TY - JOUR
A1 - Lange, Bastian
A1 - Bürkner, Hans-Joachim
T1 - Ambiguous avant-gardes and their geographies
BT - on blank spots of the postgrowth debate
JF - Die Erde : journal of the Geographical Society of Berlin ; Zeitschrift der Gesellschaft für Erdkunde zu Berlin
N2 - In the following article, the focus is on the transformative potentials created by so-called persistence avant-gardes and prevention innovators. The text extends Bluhdorn's guiding concept of narratives of hope (Bluhdorn 2017; Bluhdorn and Butzlaff 2019) by considering those groups that are marginalized within debates on socio-ecological transformation. With a closer look at the narratives of prevention and blockade that these actors engage, the ambiguous nature of postgrowth avant-gardes is carved out. Their discursive, argumentative, and effective inhibition of transitory policies is interpreted as a pro-active potential, rather than a mere obstacle to socio-ecological transformation. Adding a geographical perspective, the paper pleads for a more precise theoretical penetration of the ambivalent figure of avantgardes when analyzing processes of local and regional postgrowth.
N2 - Mit dem Beitrag richten wir den Fokus auf transformative Potenziale, die von sogenannten Beharrungsavantgar-den und Präventionsinnovatoren ausgehen. Der Text erweitert Blühdorns Leitkonzept der Hoffnungsnarrative (Blühdorn 2017; Blühdorn and Butzlaff 2019), indem er jene Gruppen in den Blick nimmt, die in den Debatten um die sozial-ökologische Transformation marginalisiert werden. Mit einem genaueren Blick auf die Präventions- und Blockade-Narrative dieser Akteure wird die Mehrdeutigkeit der Postwachstumsavantgarden herausgear-beitet. Ihre diskursive, argumentative und effektive Verhinderung transitorischer Politiken wird als proaktives Potenzial und nicht als bloßes Hindernis für eine sozial-ökologische Transformation interpretiert. Unter Hinzu-nahme einer geographischen Perspektive plädiert der Beitrag für eine präzisere theoretische Durchdringung der ambivalenten Figur der Avantgarden bei der Analyse lokaler und regionaler Postwachstumsvorgänge.
KW - alternative economies
KW - transformative policies
KW - change agents
KW - postgrowth
KW - regional development
KW - East Germany
Y1 - 2021
U6 - https://doi.org/10.12854/erde-2021-566
SN - 0013-9998
VL - 152
IS - 4
SP - 273
EP - 287
PB - Gesellschaft für Erdkunde
CY - Berlin
ER -
TY - JOUR
A1 - Scherler, Dirk
A1 - Schwanghart, Wolfgang
T1 - Drainage divide networks - part 1: Identification and ordering in digital elevation models
JF - Earth surface dynamics : ESURF
N2 - We propose a novel way to measure and analyze networks of drainage divides from digital elevation models. We developed an algorithm that extracts drainage divides based on the drainage basin boundaries defined by a stream network. In contrast to streams, there is no straightforward approach to order and classify divides, although it is intuitive that some divides are more important than others. A meaningful way of ordering divides is the average distance one would have to travel down on either side of a divide to reach a common stream location. However, because measuring these distances is computationally expensive and prone to edge effects, we instead sort divide segments based on their tree-like network structure, starting from endpoints at river confluences. The sorted nature of the network allows for assigning distances to points along the divides, which can be shown to scale with the average distance downslope to the common stream location. Furthermore, because divide segments tend to have characteristic lengths, an ordering scheme in which divide orders increase by 1 at junctions mimics these distances. We applied our new algorithm to the Big Tujunga catchment in the San Gabriel Mountains of southern California and studied the morphology of the drainage divide network. Our results show that topographic metrics, like the downstream flow distance to a stream and hillslope relief, attain characteristic values that depend on the drainage area threshold used to derive the stream network. Portions along the divide network that have lower than average relief or are closer than average to streams are often distinctly asymmetric in shape, suggesting that these divides are unstable. Our new and automated approach thus helps to objectively extract and analyze divide networks from digital elevation models.
Y1 - 2020
U6 - https://doi.org/10.5194/esurf-8-245-2020
SN - 2196-6311
SN - 2196-632X
VL - 8
IS - 2
SP - 245
EP - 259
PB - Copernicus Publ.
CY - Göttingen
ER -
TY - JOUR
A1 - Wehrhan, Marc
A1 - Puppe, Daniel
A1 - Kaczorek, Danuta
A1 - Sommer, Michael
T1 - Spatial patterns of aboveground phytogenic Si stocks in a grass-dominated catchment
BT - results from UAS-based high-resolution remote sensing
JF - Biogeosciences : BG
N2 - Various studies have been performed to quantify silicon (Si) stocks in plant biomass and related Si fluxes in terrestrial biogeosystems. Most studies are deliberately designed on the plot scale to ensure low heterogeneity in soils and plant composition, hence similar environmental conditions. Due to the immanent spatial soil variability, the transferability of results to larger areas, such as catchments, is therefore limited. However, the emergence of new technical features and increasing knowledge on details in Si cycling lead to a more complex picture at landscape and catchment scales. Dynamic and static soil properties change along the soil continuum and might influence not only the species composition of natural vegetation but also its biomass distribution and related Si stocks. Maximum likelihood (ML) classification was applied to multispectral imagery captured by an unmanned aerial system (UAS) aiming at the identification of land cover classes (LCCs). Subsequently, the normalized difference vegetation index (NDVI) and ground-based measurements of biomass were used to quantify aboveground Si stocks in two Si-accumulating plants (Calamagrostis epige-jos and Phragmites australis) in a heterogeneous catchment and related corresponding spatial patterns of these stocks to soil properties. We found aboveground Si stocks of C. epige-jos and P. australis to be surprisingly high (maxima of Si stocks reach values up to 98 g Sim(-2)), i.e. comparable to or markedly exceeding reported values for the Si storage in aboveground vegetation of various terrestrial ecosystems. We further found spatial patterns of plant aboveground Si stocks to reflect spatial heterogeneities in soil properties. From our results, we concluded that (i) aboveground biomass of plants seems to be the main factor of corresponding phytogenic Si stock quantities, and (ii) a detection of biomass heterogeneities via UAS-based remote sensing represents a promising tool for the quantification of lifelike phytogenic Si pools at landscape scales.
Y1 - 2021
U6 - https://doi.org/10.5194/bg-18-5163-2021
SN - 1726-4170
SN - 1726-4189
VL - 18
IS - 18
SP - 5163
EP - 5183
PB - Copernicus
CY - Göttingen
ER -
TY - JOUR
A1 - Herrero, Mario
A1 - Thornton, Philip K.
A1 - Mason-D'Croz, Daniel
A1 - Palmer, Jeda
A1 - Bodirsky, Benjamin Leon
A1 - Pradhan, Prajal
A1 - Barrett, Christopher B.
A1 - Benton, Tim G.
A1 - Hall, Andrew
A1 - Pikaar, Ilje
A1 - Bogard, Jessica R.
A1 - Bonnett, Graham D.
A1 - Bryan, Brett A.
A1 - Campbell, Bruce M.
A1 - Christensen, Svend
A1 - Clark, Michael
A1 - Fanzo, Jessica
A1 - Godde, Cecile M.
A1 - Jarvis, Andy
A1 - Loboguerrero, Ana Maria
A1 - Mathys, Alexander
A1 - McIntyre, C. Lynne
A1 - Naylor, Rosamond L.
A1 - Nelson, Rebecca
A1 - Obersteiner, Michael
A1 - Parodi, Alejandro
A1 - Popp, Alexander
A1 - Ricketts, Katie
A1 - Smith, Pete
A1 - Valin, Hugo
A1 - Vermeulen, Sonja J.
A1 - Vervoort, Joost
A1 - van Wijk, Mark
A1 - van Zanten, Hannah H. E.
A1 - West, Paul C.
A1 - Wood, Stephen A.
A1 - Rockström, Johan
T1 - Articulating the effect of food systems innovation on the Sustainable Development Goals
JF - The lancet Planetary health
N2 - Food system innovations will be instrumental to achieving multiple Sustainable Development Goals (SDGs). However, major innovation breakthroughs can trigger profound and disruptive changes, leading to simultaneous and interlinked reconfigurations of multiple parts of the global food system. The emergence of new technologies or social solutions, therefore, have very different impact profiles, with favourable consequences for some SDGs and unintended adverse side-effects for others. Stand-alone innovations seldom achieve positive outcomes over multiple sustainability dimensions. Instead, they should be embedded as part of systemic changes that facilitate the implementation of the SDGs. Emerging trade-offs need to be intentionally addressed to achieve true sustainability, particularly those involving social aspects like inequality in its many forms, social justice, and strong institutions, which remain challenging. Trade-offs with undesirable consequences are manageable through the development of well planned transition pathways, careful monitoring of key indicators, and through the implementation of transparent science targets at the local level.
Y1 - 2020
U6 - https://doi.org/10.1016/S2542-5196(20)30277-1
SN - 2542-5196
VL - 5
IS - 1
SP - E50
EP - E62
PB - Elsevier
CY - Oxford
ER -
TY - JOUR
A1 - Rockström, Johan
T1 - Speeding up state-of-the-art assessments on global sustainability
BT - introducing the Cambridge Sustainability Commissions
JF - Global sustainability
Y1 - 2022
U6 - https://doi.org/10.1017/sus.2022.1
SN - 2059-4798
VL - 5
PB - Cambridge University Press
CY - Cambridge
ER -
TY - JOUR
A1 - Fournier, Bertrand
A1 - Steiner, Magdalena
A1 - Brochet, Xavier
A1 - Degrune, Florine
A1 - Mammeri, Jibril
A1 - Carvalho, Diogo Leite
A1 - Siliceo, Sara Leal
A1 - Bacher, Sven
A1 - Peña-Reyes, Carlos Andrés
A1 - Heger, Thierry Jean
T1 - Toward the use of protists as bioindicators of multiple stresses in agricultural soils
BT - a case study in vineyard ecosystems
JF - Ecological indicators : integrating monitoring, assessment and management
N2 - Management of agricultural soil quality requires fast and cost-efficient methods to identify multiple stressors that can affect soil organisms and associated ecological processes. Here, we propose to use soil protists which have a great yet poorly explored potential for bioindication. They are ubiquitous, highly diverse, and respond to various stresses to agricultural soils caused by frequent management or environmental changes. We test an approach that combines metabarcoding data and machine learning algorithms to identify potential stressors of soil protist community composition and diversity. We measured 17 key variables that reflect various potential stresses on soil protists across 132 plots in 28 Swiss vineyards over 2 years. We identified the taxa showing strong responses to the selected soil variables (potential bioindicator taxa) and tested for their predictive power. Changes in protist taxa occurrence and, to a lesser extent, diversity metrics exhibited great predictive power for the considered soil variables. Soil copper concentration, moisture, pH, and basal respiration were the best predicted soil variables, suggesting that protists are particularly responsive to stresses caused by these variables. The most responsive taxa were found within the clades Rhizaria and Alveolata. Our results also reveal that a majority of the potential bioindicators identified in this study can be used across years, in different regions and across different grape varieties. Altogether, soil protist metabarcoding data combined with machine learning can help identifying specific abiotic stresses on microbial communities caused by agricultural management. Such an approach provides complementary information to existing soil monitoring tools that can help manage the impact of agricultural practices on soil biodiversity and quality.
KW - Biomonitoring
KW - Machine learning
KW - Predictive model
KW - Soil function
KW - Soil
KW - quality
KW - Microbial ecology
Y1 - 2022
U6 - https://doi.org/10.1016/j.ecolind.2022.108955
SN - 1470-160X
SN - 1872-7034
VL - 139
PB - Elsevier
CY - Amsterdam
ER -
TY - JOUR
A1 - Soergel, Bjoern
A1 - Kriegler, Elmar
A1 - Bodirsky, Benjamin Leon
A1 - Bauer, Nico
A1 - Leimbach, Marian
A1 - Popp, Alexander
T1 - Combining ambitious climate policies with efforts to eradicate poverty
JF - Nature Communications
N2 - Climate change threatens to undermine efforts to eradicate extreme poverty. However, climate policies could impose a financial burden on the global poor through increased energy and food prices. Here, we project poverty rates until 2050 and assess how they are influenced by mitigation policies consistent with the 1.5 degrees C target. A continuation of historical trends will leave 350 million people globally in extreme poverty by 2030. Without progressive redistribution, climate policies would push an additional 50 million people into poverty. However, redistributing the national carbon pricing revenues domestically as an equal-per-capita climate dividend compensates this policy side effect, even leading to a small net reduction of the global poverty headcount (-6 million). An additional international climate finance scheme enables a substantial poverty reduction globally and also in Sub-Saharan Africa. Combining national redistribution with international climate finance thus provides an important entry point to climate policy in developing countries. Ambitious climate policies can negatively impact the global poor by affecting income, food and energy prices. Here, the authors quantify this effect, and show that it can be compensated by national redistribution of the carbon pricing revenues in combination with international climate finance.
Y1 - 2021
U6 - https://doi.org/10.1038/s41467-021-22315-9
SN - 2041-1723
VL - 12
PB - Nature Publishing Group
CY - London
ER -
TY - JOUR
A1 - Schaller, Jörg
A1 - Scherwietes, Eric
A1 - Gerber, Lukas
A1 - Vaidya, Shrijana
A1 - Kaczorek, Danuta
A1 - Pausch, Johanna
A1 - Barkusky, Dietmar
A1 - Sommer, Michael
A1 - Hoffmann, Mathias
T1 - Silica fertilization improved wheat performance and increased phosphorus concentrations during drought at the field scale
JF - Scientific reports
N2 - Drought and the availability of mineable phosphorus minerals used for fertilization are two of the important issues agriculture is facing in the future. High phosphorus availability in soils is necessary to maintain high agricultural yields. Drought is one of the major threats for terrestrial ecosystem performance and crop production in future. Among the measures proposed to cope with the upcoming challenges of intensifying drought stress and to decrease the need for phosphorus fertilizer application is the fertilization with silica (Si). Here we tested the importance of soil Si fertilization on wheat phosphorus concentration as well as wheat performance during drought at the field scale. Our data clearly showed a higher soil moisture for the Si fertilized plots. This higher soil moisture contributes to a better plant performance in terms of higher photosynthetic activity and later senescence as well as faster stomata responses ensuring higher productivity during drought periods. The plant phosphorus concentration was also higher in Si fertilized compared to control plots. Overall, Si fertilization or management of the soil Si pools seem to be a promising tool to maintain crop production under predicted longer and more serve droughts in the future and reduces phosphorus fertilizer requirements.
Y1 - 2021
U6 - https://doi.org/10.1038/s41598-021-00464-7
SN - 2045-2322
VL - 11
IS - 1
PB - Macmillan Publishers Limited, part of Springer Nature
CY - [London]
ER -
TY - JOUR
A1 - Koç, Gamze
A1 - Petrow, Theresia
A1 - Thieken, Annegret
T1 - Analysis of the Most Severe Flood Events in Turkey (1960–2014)
BT - Which Triggering Mechanisms and Aggravating Pathways Can be Identified?
JF - Water
N2 - The most severe flood events in Turkey were determined for the period 1960–2014 by considering the number of fatalities, the number of affected people, and the total economic losses as indicators. The potential triggering mechanisms (i.e., atmospheric circulations and precipitation amounts) and aggravating pathways (i.e., topographic features, catchment size, land use types, and soil properties) of these 25 events were analyzed. On this basis, a new approach was developed to identify the main influencing factor per event and to provide additional information for determining the dominant flood occurrence pathways for severe floods. The events were then classified through hierarchical cluster analysis. As a result, six different clusters were found and characterized. Cluster 1 comprised flood events that were mainly influenced by drainage characteristics (e.g., catchment size and shape); Cluster 2 comprised events aggravated predominantly by urbanization; steep topography was identified to be the dominant factor for Cluster 3; extreme rainfall was determined as the main triggering factor for Cluster 4; saturated soil conditions were found to be the dominant factor for Cluster 5; and orographic effects of mountain ranges characterized Cluster 6. This study determined pathway patterns of the severe floods in Turkey with regard to their main causal or aggravating mechanisms. Accordingly, geomorphological properties are of major importance in large catchments in eastern and northeastern Anatolia. In addition, in small catchments, the share of urbanized area seems to be an important factor for the extent of flood impacts. This paper presents an outcome that could be used for future urban planning and flood risk prevention studies to understand the flood mechanisms in different regions of Turkey.
KW - hierarchical clustering
KW - Hess-Brezowsky Großwetterlagen classification
KW - ERA5
KW - flood hazards
KW - pathway
KW - Turkey
Y1 - 2020
U6 - https://doi.org/10.3390/w12061562
SN - 2073-4441
VL - 12
IS - 6
PB - MDPI
CY - Basel
ER -
TY - JOUR
A1 - Laudan, Jonas
A1 - Zöller, Gert
A1 - Thieken, Annegret
T1 - Flash floods versus river floods
BT - a comparison of psychological impacts and implications for precautionary behaviour
JF - Natural Hazards and Earth System Sciences
N2 - River floods are among the most damaging natural hazards that frequently occur in Germany. Flooding causes high economic losses and impacts many residents. In 2016, several southern German municipalities were hit by flash floods after unexpectedly severe heavy rainfall, while in 2013 widespread river flooding had occurred. This study investigates and compares the psychological impacts of river floods and flash floods and potential consequences for precautionary behaviour. Data were collected using computer-aided telephone interviews that were conducted among flood-affected households around 9 months after each damaging event. This study applies Bayesian statistics and negative binomial regressions to test the suitability of psychological indicators to predict the precaution motivation of individuals. The results show that it is not the particular flood type but rather the severity and local impacts of the event that are crucial for the different, and potentially negative, impacts on mental health. According to the used data, however, predictions of the individual precaution motivation should not be based on the derived psychological indicators – i.e. coping appraisal, threat appraisal, burden and evasion – since their explanatory power was generally low and results are, for the most part, non-significant. Only burden reveals a significant positive relation to planned precaution regarding weak flash floods. In contrast to weak flash floods and river floods, the perceived threat of strong flash floods is significantly lower although feelings of burden and lower coping appraisals are more pronounced. Further research is needed to better include psychological assessment procedures and to focus on alternative data sources regarding floods and the connected precaution motivation of affected residents.
KW - private households
KW - risk perceptions
KW - extreme rainfall
KW - health
KW - mitigation
KW - Germany
KW - people
KW - damage
KW - preparedness
KW - residents
Y1 - 2019
U6 - https://doi.org/10.5194/nhess-20-999-2020
SN - 1684-9981
VL - 20
SP - 999
EP - 1023
PB - European Geophysical Society
CY - Katlenburg-Lindau
ER -
TY - JOUR
A1 - Hudson, Paul
A1 - Pham, My
A1 - Hagedoorn, Liselotte
A1 - Thieken, Annegret
A1 - Lasage, Ralph
A1 - Bubeck, Philip
T1 - Self-stated recovery from flooding
BT - empirical results from a survey in Central Vietnam
JF - Journal of Flood Risk Management
N2 - Social inequalities lead to flood resilience inequalities across social groups, a topic that requires improved documentation and understanding. The objective of this paper is to attend to these differences by investigating self-stated flood recovery across genders in Vietnam as a conceptual replication of earlier results from Germany. This study employs a regression-based analysis of 1,010 respondents divided between a rural coastal and an urban community in Thua Thien-Hue province. The results highlight an important set of recovery process-related variables. The set of relevant variables is similar across genders in terms of inclusion and influence, and includes age, social capital, internal and external support after a flood, perceived severity of previous flood impacts, and the perception of stress-resilience. However, women were affected more heavily by flooding in terms of longer recovery times, which should be accounted for in risk management. Overall, the studied variables perform similarly in Vietnam and Germany. This study, therefore, conceptually replicates previous results suggesting that women display slightly slower recovery levels as well as that psychological variables influence recovery rates more than adverse flood impacts. This provides an indication of the results' potentially robust nature due to the different socio-environmental contexts in Germany and Vietnam.
KW - flood recovery
KW - resilience
KW - societal equity
KW - vulnerability
Y1 - 2020
U6 - https://doi.org/10.1111/jfr3.12680
SN - 1753-318X
VL - 14
PB - Wiley-Blackwell
CY - Oxford
ER -
TY - JOUR
A1 - Jehmlich, Caroline
A1 - Hudson, Paul
A1 - Thieken, Annegret
T1 - Short contribution on adaptive behaviour of flood-prone companies
BT - a pilot study of Dresden-Laubegast, Germany
JF - Journal of Flood Risk Management
N2 - Integrated flood management strategies consider property-level precautionary measures as a vital part. Whereas this is a well-researched topic for residents, little is known about the adaptive behaviour of flood-prone companies although they often settle on the ground floor of buildings and are thus among the first affected by flooding. This pilot study analyses flood responses of 64 businesses in a district of the city of Dresden, Germany that experienced major flooding in 2002 and 2013. Using standardised survey data and accompanying qualitative interviews, the analyses revealed that the largest driver of adaptive behaviour is experiencing flood events. Intangible factors such as tradition and a sense of community play a role for the decision to stay in the area, while lacking ownership might hamper property-level adaptation. Further research is also needed to understand the role of insurance and governmental aid for recovery and adaptation of businesses.
KW - adaptation
KW - disaster risk reduction
KW - integrated flood risk management
KW - risk perception
Y1 - 2019
U6 - https://doi.org/10.1111/jfr3.12653
SN - 1753-318X
VL - 13
PB - Wiley-Blackwell
CY - Oxford
ER -
TY - JOUR
A1 - Samprogna Mohor, Guilherme
A1 - Thieken, Annegret
A1 - Korup, Oliver
T1 - Residential flood loss estimated from Bayesian multilevel models
JF - Natural Hazards and Earth System Sciences
N2 - Models for the predictions of monetary losses from floods mainly blend data deemed to represent a single flood type and region. Moreover, these approaches largely ignore indicators of preparedness and how predictors may vary between regions and events, challenging the transferability of flood loss models. We use a flood loss database of 1812 German flood-affected households to explore how Bayesian multilevel models can estimate normalised flood damage stratified by event, region, or flood process type. Multilevel models acknowledge natural groups in the data and allow each group to learn from others. We obtain posterior estimates that differ between flood types, with credibly varying influences of water depth, contamination, duration, implementation of property-level precautionary measures, insurance, and previous flood experience; these influences overlap across most events or regions, however. We infer that the underlying damaging processes of distinct flood types deserve further attention. Each reported flood loss and affected region involved mixed flood types, likely explaining the uncertainty in the coefficients. Our results emphasise the need to consider flood types as an important step towards applying flood loss models elsewhere. We argue that failing to do so may unduly generalise the model and systematically bias loss estimations from empirical data.
KW - damage
KW - insurance
KW - Germany
KW - transferability
KW - preparedness
KW - recovery
Y1 - 2020
U6 - https://doi.org/10.5194/nhess-21-1599-2021
SN - 2195-9269
VL - 21
SP - 1599
EP - 1614
PB - European Geophysical Society
CY - Katlenburg-Lindau
ER -
TY - JOUR
A1 - Koc, Gamze
A1 - Petrow, Theresia
A1 - Thieken, Annegret
T1 - Analysis of the most severe flood events in Turkey (1960-2014)
BT - which triggering mechanisms and aggravating pathways can be identified?
JF - Water / Molecular Diversity Preservation International (MDPI)
N2 - The most severe flood events in Turkey were determined for the period 1960-2014 by considering the number of fatalities, the number of affected people, and the total economic losses as indicators. The potential triggering mechanisms (i.e., atmospheric circulations and precipitation amounts) and aggravating pathways (i.e., topographic features, catchment size, land use types, and soil properties) of these 25 events were analyzed. On this basis, a new approach was developed to identify the main influencing factor per event and to provide additional information for determining the dominant flood occurrence pathways for severe floods. The events were then classified through hierarchical cluster analysis. As a result, six different clusters were found and characterized. Cluster 1 comprised flood events that were mainly influenced by drainage characteristics (e.g., catchment size and shape); Cluster 2 comprised events aggravated predominantly by urbanization; steep topography was identified to be the dominant factor for Cluster 3; extreme rainfall was determined as the main triggering factor for Cluster 4; saturated soil conditions were found to be the dominant factor for Cluster 5; and orographic effects of mountain ranges characterized Cluster 6. This study determined pathway patterns of the severe floods in Turkey with regard to their main causal or aggravating mechanisms. Accordingly, geomorphological properties are of major importance in large catchments in eastern and northeastern Anatolia. In addition, in small catchments, the share of urbanized area seems to be an important factor for the extent of flood impacts. This paper presents an outcome that could be used for future urban planning and flood risk prevention studies to understand the flood mechanisms in different regions of Turkey.
KW - hierarchical clustering
KW - Hess-Brezowsky Grosswetterlagen classification
KW - ERA5
KW - flood hazards
KW - pathway
KW - Turkey
Y1 - 2020
U6 - https://doi.org/10.3390/w12061562
SN - 2073-4441
VL - 12
IS - 6
PB - MDPI
CY - Basel
ER -
TY - JOUR
A1 - Kellermann, Patric
A1 - Schröter, Kai
A1 - Thieken, Annegret
A1 - Haubrock, Sören-Nils
A1 - Kreibich, Heidi
T1 - The object-specific flood damage database HOWAS 21
JF - Natural hazards and earth system sciences
N2 - The Flood Damage Database HOWAS 21 contains object-specific flood damage data resulting from fluvial, pluvial and groundwater flooding. The datasets incorporate various variables of flood hazard, exposure, vulnerability and direct tangible damage at properties from several economic sectors. The main purpose of development of HOWAS 21 was to support forensic flood analysis and the derivation of flood damage models. HOWAS 21 was first developed for Germany and currently almost exclusively contains datasets from Germany. However, its scope has recently been enlarged with the aim to serve as an international flood damage database; e.g. its web application is now available in German and English. This paper presents the recent advancements of HOWAS 21 and highlights exemplary analyses to demonstrate the use of HOWAS 21 flood damage data. The data applications indicate a large potential of the database for fostering a better understanding and estimation of the consequences of flooding.
Y1 - 2020
U6 - https://doi.org/10.5194/nhess-20-2503-2020
SN - 1561-8633
SN - 1684-9981
VL - 20
IS - 9
SP - 2503
EP - 2519
PB - Copernicus
CY - Göttingen
ER -
TY - JOUR
A1 - Wutzler, Bianca
A1 - Hudson, Paul
A1 - Thieken, Annegret
T1 - Adaptation strategies of flood-damaged businesses in Germany
JF - Frontiers in Water
N2 - Flood risk management in Germany follows an integrative approach in which both private households and businesses can make an important contribution to reducing flood damage by implementing property-level adaptation measures. While the flood adaptation behavior of private households has already been widely researched, comparatively less attention has been paid to the adaptation strategies of businesses. However, their ability to cope with flood risk plays an important role in the social and economic development of a flood-prone region. Therefore, using quantitative survey data, this study aims to identify different strategies and adaptation drivers of 557 businesses damaged by a riverine flood in 2013 and 104 businesses damaged by pluvial or flash floods between 2014 and 2017. Our results indicate that a low perceived self-efficacy may be an important factor that can reduce the motivation of businesses to adapt to flood risk. Furthermore, property-owners tended to act more proactively than tenants. In addition, high experience with previous flood events and low perceived response costs could strengthen proactive adaptation behavior. These findings should be considered in business-tailored risk communication.
KW - risk management
KW - climate change adaptation
KW - floods
KW - disaster risk reduction
KW - Germany
KW - precaution
KW - emergency management
Y1 - 2022
U6 - https://doi.org/10.3389/frwa.2022.932061
SN - 2624-9375
PB - Frontiers Media SA
CY - Lausanne, Schweiz
ER -
TY - JOUR
A1 - Goetz, Jason
A1 - Kohrs, Robin
A1 - Parra Hormazábal, Eric
A1 - Bustos Morales, Manuel
A1 - Araneda Riquelme, María Belén
A1 - Henríquez Ruiz, Cristian
A1 - Brenning, Alexander
T1 - Optimizing and validating the Gravitational Process Path model for regional debris-flow runout modelling
JF - Natural hazards and earth system sciences : NHESS / European Geophysical Society
N2 - Knowing the source and runout of debris flows can help in planning strategies aimed at mitigating these hazards. Our research in this paper focuses on developing a novel approach for optimizing runout models for regional susceptibility modelling, with a case study in the upper Maipo River basin in the Andes of Santiago, Chile. We propose a two-stage optimization approach for automatically selecting parameters for estimating runout path and distance. This approach optimizes the random-walk and Perla et al.'s (PCM) two-parameter friction model components of the open-source Gravitational Process Path (GPP) modelling framework. To validate model performance, we assess the spatial transferability of the optimized runout model using spatial crossvalidation, including exploring the model's sensitivity to sample size. We also present diagnostic tools for visualizing uncertainties in parameter selection and model performance. Although there was considerable variation in optimal parameters for individual events, we found our runout modelling approach performed well at regional prediction of potential runout areas. We also found that although a relatively small sample size was sufficient to achieve generally good runout modelling performance, larger samples sizes (i.e. >= 80) had higher model performance and lower uncertainties for estimating runout distances at unknown locations. We anticipate that this automated approach using the open-source R software and the System for Automated Geoscientific Analyses geographic information system (SAGA-GIS) will make process-based debris-flow models more readily accessible and thus enable researchers and spatial planners to improve regional-scale hazard assessments.
Y1 - 2021
U6 - https://doi.org/10.5194/nhess-21-2543-2021
SN - 1561-8633
SN - 1684-9981
VL - 21
IS - 8
SP - 2543
EP - 2562
PB - European Geophysical Society
CY - Katlenburg-Lindau
ER -
TY - JOUR
A1 - Müller, Sebastian
A1 - Schüler, Lennart
A1 - Zech, Alraune
A1 - Heße, Falk
T1 - GSTools v1.3: a toolbox for geostatistical modelling in Python
JF - Geoscientific model development : an interactive open access journal of the European Geosciences Union
N2 - Geostatistics as a subfield of statistics accounts for the spatial correlations encountered in many applications of, for example, earth sciences. Valuable information can be extracted from these correlations, also helping to address the often encountered burden of data scarcity. Despite the value of additional data, the use of geostatistics still falls short of its potential. This problem is often connected to the lack of user-friendly software hampering the use and application of geostatistics. We therefore present GSTools, a Python-based software suite for solving a wide range of geostatistical problems. We chose Python due to its unique balance between usability, flexibility, and efficiency and due to its adoption in the scientific community. GSTools provides methods for generating random fields; it can perform kriging, variogram estimation and much more. We demonstrate its abilities by virtue of a series of example applications detailing their use.
Y1 - 2022
U6 - https://doi.org/10.5194/gmd-15-3161-2022
SN - 1991-959X
SN - 1991-9603
VL - 15
IS - 7
SP - 3161
EP - 3182
PB - Copernicus
CY - Göttingen
ER -
TY - JOUR
A1 - Bauer, Jonas
A1 - Börsig, Nicolas
A1 - Pham, Van Cam
A1 - Hoan, Tran Viet
A1 - Nguyen, Ha Thi
A1 - Norra, Stefan
T1 - Geochemistry and evolution of groundwater resources in the context of salinization and freshening in the southernmost Mekong Delta, Vietnam
JF - Journal of Hydrology: Regional Studies
N2 - Study region:
Ca Mau Province (CMP), Mekong Delta (MD), Vietnam.
Study focus:
Groundwater from deep aquifers is the most reliable source of freshwater in the MD but extensive overexploitation in the last decades led to the drop of hydraulic heads and negative environmental impacts. Therefore, a comprehensive groundwater investigation was conducted to evaluate its composition in the context of Quaternary marine transgression and regression cycles, geochemical processes as well as groundwater extraction.
New hydrological insights for the region:
The abundance of groundwater of Na-HCO3 type and distinct ion ratios, such as Na+/Cl-, indicate extensive freshwater intrusion in an initially saline hydrogeological system, with decreasing intensity from upper Pleistocene to deeper Miocene aquifers, most likely during the last marine regression phase 60-12 ka BP. Deviations from the conservative mixing line between the two endmembers seawater and freshwater are attributed to ion-exchange processes on mineral surfaces, making ion ratios in combination with a customized water type analysis a useful tool to distinguish between salinization and freshening processes. Elevated salinity in some areas is attributed to HCO3- generation by organic matter decomposition in marine sediments rather than to seawater intrusion. Nevertheless, a few randomly distributed locations show strong evidence of recent salinization in an early stage, which may be caused by the downwards migration of saline Holocene groundwater through natural and anthropogenic pathways into deep aquifers.
KW - Ca Mau
KW - Hydrogeology
KW - Delta aquifer system
KW - Salinity
KW - Freshwater
KW - Seawater intrusion
Y1 - 2022
U6 - https://doi.org/10.1016/j.ejrh.2022.101010
SN - 2214-5818
VL - 40
PB - Elsevier
CY - Amsterdam
ER -
TY - JOUR
A1 - Fairey, Brenton J.
A1 - Timmerman, Martin Jan
A1 - Sudo, Masafumi
A1 - Tsikos, Harilaos
T1 - The role of hydrothermal activity in the formation of Karst-hosted manganese deposits of the Postmasburg Mn Field, Northern Cape Province, South Africa
JF - Minerals
N2 - The Postmasburg Manganese Field (PMF), Northern Cape Province, South Africa, once represented one of the largest sources of manganese ore worldwide. Two belts of manganese ore deposits have been distinguished in the PMF, namely the Western Belt of ferruginous manganese ores and the Eastern Belt of siliceous manganese ores. Prevailing models of ore formation in these two belts invoke karstification of manganese-rich dolomites and residual accumulation of manganese wad which later underwent diagenetic and low-grade metamorphic processes. For the most part, the role of hydrothermal processes and metasomatic alteration towards ore formation has not been adequately discussed. Here we report an abundance of common and some rare Al-, Na-, K- and Ba-bearing minerals, particularly aegirine, albite, microcline, banalsite, serandite-pectolite, paragonite and natrolite in Mn ores of the PMF, indicative of hydrothermal influence. Enrichments in Na, K and/or Ba in the ores are generally on a percentage level for most samples analysed through bulk-rock techniques. The presence of As-rich tokyoite also suggests the presence of As and V in the hydrothermal fluid. The fluid was likely oxidized and alkaline in nature, akin to a mature basinal brine. Various replacement textures, particularly of Na- and K- rich minerals by Ba-bearing phases, suggest sequential deposition of gangue as well as ore-minerals from the hydrothermal fluid, with Ba phases being deposited at a later stage. The stratigraphic variability of the studied ores and their deviation from the strict classification of ferruginous and siliceous ores in the literature, suggests that a re-evaluation of genetic models is warranted. New Ar-Ar ages for K-feldspars suggest a late Neoproterozoic timing for hydrothermal activity. This corroborates previous geochronological evidence for regional hydrothermal activity that affected Mn ores at the PMF but also, possibly, the high-grade Mn ores of the Kalahari Manganese Field to the north. A revised, all-encompassing model for the development of the manganese deposits of the PMF is then proposed, whereby the source of metals is attributed to underlying carbonate rocks beyond the Reivilo Formation of the Campbellrand Subgroup. The main process by which metals are primarily accumulated is attributed to karstification of the dolomitic substrate. The overlying Asbestos Hills Subgroup banded iron formation (BIF) is suggested as a potential source of alkali metals, which also provides a mechanism for leaching of these BIFs to form high-grade residual iron ore deposits.
KW - manganese ore
KW - Postmasburg manganese field
KW - hydrothermal
KW - karst
KW - South Africa
Y1 - 2019
U6 - https://doi.org/10.3390/min9070408
SN - 2075-163X
VL - 9
IS - 7
PB - MDPI
CY - Basel
ER -
TY - JOUR
A1 - Neugart, Susanne
A1 - Wiesner-Reinhold, Melanie
A1 - Frede, Katja
A1 - Jander, Elisabeth
A1 - Homann, Thomas
A1 - Rawel, Harshadrai Manilal
A1 - Schreiner, Monika
A1 - Baldermann, Susanne
T1 - Effect of Solid Biological Waste Compost on the Metabolite Profile of Brassica rapa ssp chinensis
JF - Frontiers in plant science : FPLS
N2 - Large quantities of biological waste are generated at various steps within the food production chain and a great utilization potential for this solid biological waste exists apart from the current main usage for the feedstuff sector. It remains unclear how the usage of biological waste as compost modulates plant metabolites. We investigated the effect of biological waste of the processing of coffee, aronia, and hop added to soil on the plant metabolite profile by means of liquid chromatography in pak choi sprouts. Here we demonstrate that the solid biological waste composts induced specific changes in the metabolite profiles and the changes are depending on the type of the organic residues and its concentration in soil. The targeted analysis of selected plant metabolites, associated with health beneficial properties of the Brassicaceae family, revealed increased concentrations of carotenoids (up to 3.2-fold) and decreased amounts of glucosinolates (up to 4.7-fold) as well as phenolic compounds (up to 1.5-fold).
KW - metabolite profiling
KW - LC/MS
KW - pak choi
KW - carotenoids
KW - phenolic compounds
KW - glucosinolates
Y1 - 2018
U6 - https://doi.org/10.3389/fpls.2018.00305
SN - 1664-462X
VL - 9
PB - Frontiers Media
CY - Lausanne
ER -
TY - JOUR
A1 - Jobe, Jessica Ann Thompson
A1 - Li, Tao
A1 - Bookhagen, Bodo
A1 - Chen, Jie
A1 - Burbank, Douglas W.
T1 - Dating growth strata and basin fill by combining Al-26/Be-10 burial dating and magnetostratigraphy
BT - Constraining active deformation in the Pamir-Tian Shan convergence zone, NW China
JF - Lithosphere
N2 - Cosmogenic burial dating enables dating of coarse-grained, Pliocene-Pleistocene sedimentary units that are typically difficult to date with traditional methods, such as magnetostratigraphy. In the actively deforming western Tarim Basin in NW China, Pliocene-Pleistocene conglomerates were dated at eight sites, integrating Al-26/Be-10 burial dating with previously published magnetostratigraphic sections. These samples were collected from growth strata on the flanks of growing folds and from sedimentary units beneath active faults to place timing constraints on the initiation of deformation of structures within the basin and on shortening rates on active faults. These new basin-fill and growthstrata ages document the late Neogene and Quaternary growth of the Pamir and Tian Shan orogens between >5 and 1 Ma and delineate the eastward propagation of deformation at rates up to 115 km/m.y. and basinward growth of both mountain belts at rates up to 12 km/m.y.
Y1 - 2018
U6 - https://doi.org/10.1130/L727.1
SN - 1941-8264
SN - 1947-4253
VL - 10
IS - 6
SP - 806
EP - 828
PB - American Institute of Physics
CY - Boulder
ER -
TY - JOUR
A1 - Puppe, Daniel
A1 - Leue, Martin
A1 - Sommer, Michael
A1 - Schaller, Jörg
A1 - Kaczorek, Danuta
T1 - Auto-fluorescence in phytoliths
BT - a mechanistic understanding derived from microscopic and spectroscopic analyses
JF - Frontiers in Environmental Science
N2 - The detection of auto-fluorescence in phytogenic, hydrated amorphous silica depositions (phytoliths) has been found to be a promising approach to verify if phytoliths were burnt or not, especially in archaeological contexts. However, it is unknown so far at what temperature and how auto-fluorescence is induced in phytoliths. We used fluorescence microscopy, scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDX), and Fourier transform infrared spectroscopy to analyze auto-fluorescence in modern phytoliths extracted from plant samples or in intact leaves of winter wheat. Leaves and extracted phytoliths were heated at different temperatures up to 600 degrees C. The aims of our experiments were i) to find out what temperature is needed to induce auto-fluorescence in phytoliths, ii) to detect temperature-dependent changes in the molecular structure of phytoliths related to auto-fluorescence, and iii) to derive a mechanistic understanding of auto-fluorescence in phytoliths. We found organic compounds associated with phytoliths to cause auto-fluorescence in phytoliths treated at temperatures below approx. 400 degrees C. In phytoliths treated at higher temperatures, i.e., 450 and 600 degrees C, phytolith auto-fluorescence was mainly caused by molecular changes of phytolith silica. Based on our results we propose that auto-fluorescence in phytoliths is caused by clusterization-triggered emissions, which are caused by overlapping electron clouds forming non-conventional chromophores. In phytoliths heated at temperatures above about 400 degrees C dihydroxylation and the formation of siloxanes result in oxygen clusters that serve as non-conventional chromophores in fluorescence events. Furthermore, SEM-EDX analyses revealed that extractable phytoliths were dominated by lumen phytoliths (62%) compared to cell wall phytoliths (38%). Our findings might be not only relevant in archaeological phytolith-based examinations, but also for studies on the temperature-dependent release of silicon from phytoliths and the potential of long-term carbon sequestration in phytoliths.
KW - fluorescence microscopy
KW - FTIR spectroscopy
KW - SEM-EDX
KW - burnt phytoliths;
KW - carbon sequestration
Y1 - 2022
U6 - https://doi.org/10.3389/fenvs.2022.915947
SN - 2296-665X
VL - 10
PB - Frontiers Media
CY - Lausanne
ER -
TY - JOUR
A1 - Schmidt, Martin
A1 - Nendel, Claas
A1 - Funk, Roger
A1 - Mitchell, Matthew G. E.
A1 - Lischeid, Gunnar
T1 - Modeling Yields Response to Shading in the Field-to-Forest Transition Zones in Heterogeneous Landscapes
JF - Agriculture
N2 - In crop modeling and yield predictions, the heterogeneity of agricultural landscapes is usually not accounted for. This heterogeneity often arises from landscape elements like forests, hedges, or single trees and shrubs that cast shadows. Shading from forested areas or shrubs has effects on transpiration, temperature, and soil moisture, all of which affect the crop yield in the adjacent arable land. Transitional gradients of solar irradiance can be described as a function of the distance to the zero line (edge), the cardinal direction, and the height of trees. The magnitude of yield reduction in transition zones is highly influenced by solar irradiance-a factor that is not yet implemented in crop growth models on a landscape level. We present a spatially explicit model for shading caused by forested areas, in agricultural landscapes. With increasing distance to forest, solar irradiance and yield increase. Our model predicts that the shading effect from the forested areas occurs up to 15 m from the forest edge, for the simulated wheat yields, and up to 30 m, for simulated maize. Moreover, we estimated the spatial extent of transition zones, to calculate the regional yield reduction caused by shading of the forest edges, which amounted to 5% to 8% in an exemplary region.
KW - edge effect
KW - transition zone
KW - solar irradiance
KW - crop growth
KW - maize
KW - wheat
Y1 - 2019
U6 - https://doi.org/10.3390/agriculture9010006
SN - 2077-0472
VL - 9
IS - 1
PB - MDPI
CY - Basel
ER -
TY - JOUR
A1 - Weng, Wei
A1 - Lüdeke, Matthias K. B.
A1 - Zemp, Delphine Clara
A1 - Lakes, Tobia
A1 - Kropp, Jürgen
T1 - Aerial and surface rivers
BT - downwind impacts on water availability from land use changes in Amazonia
JF - Hydrology and earth system sciences : HESS
N2 - The abundant evapotranspiration provided by the Amazon forests is an important component of the hydrological cycle, both regionally and globally. Since the last century, deforestation and expanding agricultural activities have been changing the ecosystem and its provision of moisture to the atmosphere. However, it remains uncertain how the ongoing land use change will influence rainfall, runoff, and water availability as findings from previous studies differ. Using moisture tracking experiments based on observational data, we provide a spatially detailed analysis recognizing potential teleconnection between source and sink regions of atmospheric moisture. We apply land use scenarios in upwind moisture sources and quantify the corresponding rainfall and runoff changes in downwind moisture sinks. We find spatially varying responses of water regimes to land use changes, which may explain the diverse results from previous studies. Parts of the Peruvian Amazon and western Bolivia are identified as the sink areas most sensitive to land use change in the Amazon and we highlight the current water stress by Amazonian land use change on these areas in terms of the water availability. Furthermore, we also identify the influential source areas where land use change may considerably reduce a given target sink's water reception (from our example of the Ucayali River basin outlet, rainfall by 5–12 % and runoff by 19–50 % according to scenarios). Sensitive sinks and influential sources are therefore suggested as hotspots for achieving sustainable land–water management.
Y1 - 2018
U6 - https://doi.org/10.5194/hess-22-911-2018
SN - 1027-5606
SN - 1607-7938
VL - 22
IS - 1
SP - 911
EP - 927
PB - Copernicus
CY - Göttingen
ER -
TY - JOUR
A1 - Pradhan, Prajal
A1 - Kropp, Jürgen
T1 - Interplay between diets, health, and climate change
JF - Sustainability
N2 - The world is facing a triple burden of undernourishment, obesity, and environmental impacts from agriculture while nourishing its population. This burden makes sustainable nourishment of the growing population a global challenge. Addressing this challenge requires an understanding of the interplay between diets, health, and associated environmental impacts (e.g., climate change). For this, we identify 11 typical diets that represent dietary habits worldwide for the last five decades. Plant-source foods provide most of all three macronutrients (carbohydrates, protein, and fat) in developing countries. In contrast, animal-source foods provide a majority of protein and fat in developed ones. The identified diets deviate from the recommended healthy diet with either too much (e.g., red meat) or too little (e.g., fruits and vegetables) food and nutrition supply. The total calorie supplies are lower than required for two diets. Sugar consumption is higher than recommended for five diets. Three and five diets consist of larger-than-recommended carbohydrate and fat shares, respectively. Four diets with a large share of animal-source foods exceed the recommended value of red meat. Only two diets consist of at least 400 gm/cap/day of fruits and vegetables while accounting for food waste. Prevalence of undernourishment and underweight dominates in the diets with lower calories. In comparison, a higher prevalence of obesity is observed for diets with higher calories with high shares of sugar, fat, and animal-source foods. However, embodied emissions in the diets do not show a clear relation with calorie supplies and compositions. Two high-calorie diets embody more than 1.5 t CO2eq/cap/yr, and two low-calorie diets embody around 1 t CO2eq/cap/yr. Our analysis highlights that sustainable and healthy diets can serve the purposes of both nourishing the population and, at the same time, reducing the environmental impacts of agriculture.
KW - dietary patterns
KW - healthy diets
KW - embodied emissions
KW - diet shifts
KW - sustainable diets
KW - emission intensity
Y1 - 2020
U6 - https://doi.org/10.3390/su12093878
SN - 2071-1050
VL - 12
IS - 9
PB - MDPI
CY - Basel
ER -
TY - JOUR
A1 - Krummenauer, Linda
A1 - Costa, Luís Fílípe Carvalho da
A1 - Prahl, Boris F.
A1 - Kropp, Jürgen
T1 - Future heat adaptation and exposure among urban populations and why a prospering economy alone won’t save us
JF - Scientific reports
N2 - When inferring on the magnitude of future heat-related mortality due to climate change, human adaptation to heat should be accounted for. We model long-term changes in minimum mortality temperatures (MMT), a well-established metric denoting the lowest risk of heat-related mortality, as a function of climate change and socio-economic progress across 3820 cities. Depending on the combination of climate trajectories and socio-economic pathways evaluated, by 2100 the risk to human health is expected to decline in 60% to 80% of the cities against contemporary conditions. This is caused by an average global increase in MMTs driven by long-term human acclimatisation to future climatic conditions and economic development of countries. While our adaptation model suggests that negative effects on health from global warming can broadly be kept in check, the trade-offs are highly contingent to the scenario path and location-specific. For high-forcing climate scenarios (e.g. RCP8.5) the maintenance of uninterrupted high economic growth by 2100 is a hard requirement to increase MMTs and level-off the negative health effects from additional scenario-driven heat exposure. Choosing a 2 degrees C-compatible climate trajectory alleviates the dependence on fast growth, leaving room for a sustainable economy, and leads to higher reductions of mortality risk.
Y1 - 2021
U6 - https://doi.org/10.1038/s41598-021-99757-0
SN - 2045-2322
VL - 11
IS - 1
PB - Macmillan Publishers Limited, part of Springer Nature
CY - Berlin
ER -
TY - JOUR
A1 - Athare, Tushar Ramchandra
A1 - Pradhan, Prajal
A1 - Singh, S. R. K.
A1 - Kropp, Jürgen
T1 - India consists of multiple food systems with scoioeconomic and environmental variations
JF - PLOS ONE / Public Library of Science
N2 - Agriculture in India accounts for 18% of greenhouse gas (GHG) emissions and uses significant land and water. Various socioeconomic factors and food subsidies influence diets in India. Indian food systems face the challenge of sustainably nourishing the 1.3 billion population. However, existing studies focus on a few food system components, and holistic analysis is still missing. We identify Indian food systems covering six food system components: food consumption, production, processing, policy, environmental footprints, and socioeconomic factors from the latest Indian household consumer expenditure survey. We identify 10 Indian food systems using k-means cluster analysis on 15 food system indicators belonging to the six components. Based on the major source of calorie intake, we classify the ten food systems into production-based (3), subsidy-based (3), and market-based (4) food systems. Home-produced and subsidized food contribute up to 2000 kcal/consumer unit (CU)/day and 1651 kcal/CU/day, respectively, in these food systems. The calorie intake of 2158 to 3530 kcal/CU/day in the food systems reveals issues of malnutrition in India. Environmental footprints are commensurate with calorie intake in the food systems. Embodied GHG, land footprint, and water footprint estimates range from 1.30 to 2.19 kg CO(2)eq/CU/day, 3.89 to 6.04 m(2)/CU/day, and 2.02 to 3.16 m(3)/CU/day, respectively. Our study provides a holistic understanding of Indian food systems for targeted nutritional interventions on household malnutrition in India while also protecting planetary health.
Y1 - 2022
U6 - https://doi.org/10.1371/journal.pone.0270342
SN - 1932-6203
VL - 17
IS - 8
PB - PLoS
CY - San Fransisco
ER -
TY - JOUR
A1 - Khurana, Swamini
A1 - Hesse, Falk
A1 - Kleidon-Hildebrandt, Anke
A1 - Thullner, Martin
T1 - Should we worry about surficial dynamics when assessing nutrient cycling in the groundwater?
JF - Frontiers in water
N2 - The fluxes of water and solutes in the subsurface compartment of the Critical Zone are temporally dynamic and it is unclear how this impacts microbial mediated nutrient cycling in the spatially heterogeneous subsurface. To investigate this, we undertook numerical modeling, simulating the transport in a wide range of spatially heterogeneous domains, and the biogeochemical transformation of organic carbon and nitrogen compounds using a complex microbial community with four (4) distinct functional groups, in water saturated subsurface compartments. We performed a comprehensive uncertainty analysis accounting for varying residence times and spatial heterogeneity. While the aggregated removal of chemical species in the domains over the entire simulation period was approximately the same as that in steady state conditions, the sub-scale temporal variation of microbial biomass and chemical discharge from a domain depended strongly on the interplay of spatial heterogeneity and temporal dynamics of the forcing. We showed that the travel time and the Damkohler number (Da) can be used to predict the temporally varying chemical discharge from a spatially heterogeneous domain. In homogeneous domains, chemical discharge in temporally dynamic conditions could be double of that in the steady state conditions while microbial biomass varied up to 75% of that in steady state conditions. In heterogeneous domains, the interquartile range of uncertainty in chemical discharge in reaction dominated systems (log(10)Da > 0) was double of that in steady state conditions. However, high heterogeneous domains resulted in outliers where chemical discharge could be as high as 10-20 times of that in steady state conditions in high flow periods. And in transport dominated systems (log(10)Da < 0), the chemical discharge could be half of that in steady state conditions in unusually low flow conditions. In conclusion, ignoring spatio-temporal heterogeneities in a numerical modeling approach may exacerbate inaccurate estimation of nutrient export and microbial biomass. The results are relevant to long-term field monitoring studies, and for homogeneous soil column-scale experiments investigating the role of temporal dynamics on microbial redox dynamics.
KW - reactive transport modeling
KW - spatio-temporal heterogeneity
KW - uncertainty
KW - geomicrobial activity
KW - nutrient export
Y1 - 2022
U6 - https://doi.org/10.3389/frwa.2022.780297
SN - 2624-9375
VL - 4
PB - Frontiers Media
CY - Lausanne
ER -
TY - JOUR
A1 - Schneidemesser, Erika von
A1 - Sibiya, Bheki
A1 - Caseiro, Alexandre
A1 - Butler, Tim
A1 - Lawrence, Mark
A1 - Leitao, Joana
A1 - Lupaşcu, Aura
A1 - Salvador, Pedro
T1 - Learning from the COVID-19 lockdown in Berlin
BT - Observations and modelling to support understanding policies to reduce NO2
JF - Atmospheric environment: X
N2 - Urban air pollution is a substantial threat to human health. Traffic emissions remain a large contributor to air pollution in urban areas. The mobility restrictions put in place in response to the COVID-19 pandemic provided a large-scale real-world experiment that allows for the evaluation of changes in traffic emissions and the corresponding changes in air quality. Here we use observational data, as well as modelling, to analyse changes in nitrogen dioxide, ozone, and particulate matter resulting from the COVID-19 restrictions at the height of the lockdown period in Spring of 2020. Accounting for the influence of meteorology on air quality, we found that reduction of ca. 30-50 % in traffic counts, dominated by changes in passenger cars, corresponded to reductions in median observed nitrogen dioxide concentrations of ca. 40 % (traffic and urban background locations) and a ca. 22 % increase in ozone (urban background locations) during weekdays. Lesser reductions in nitrogen dioxide concentrations were observed at urban background stations at weekends, and no change in ozone was observed. The modelled reductions in median nitrogen dioxide at urban background locations were smaller than the observed reductions and the change was not significant. The model results showed no significant change in ozone on weekdays or weekends. The lack of a simulated weekday/weekend effect is consistent with previous work suggesting that NOx emissions from traffic could be significantly underestimated in European cities by models. These results indicate the potential for improvements in air quality due to policies for reducing traffic, along with the scale of reductions that would be needed to result in meaningful changes in air quality if a transition to sustainable mobility is to be seriously considered. They also confirm once more the highly relevant role of traffic for air quality in urban areas.
KW - Urban areas
KW - Air pollution
KW - Emissions
KW - COVID-19
KW - Nitrogen dioxide
KW - Ozone
KW - Europe
Y1 - 2021
U6 - https://doi.org/10.1016/j.aeaoa.2021.100122
SN - 2590-1621
VL - 12
PB - Elsevier
CY - Amsterdam
ER -
TY - JOUR
A1 - Freymark, Jessica
A1 - Bott, Judith
A1 - Cacace, Mauro
A1 - Ziegler, Moritz 0.
A1 - Scheck-Wenderoth, Magdalena
T1 - Influence of the Main Border Faults on the 3D Hydraulic Field of the Central Upper Rhine Graben
JF - Geofluids
N2 - The Upper Rhine Graben (URG) is an active rift with a high geothermal potential. Despite being a well-studied area, the three-dimensional interaction of the main controlling factors of the thermal and hydraulic regime is still not fully understood. Therefore, we have used a data-based 3D structural model of the lithological configuration of the central URG for some conceptual numerical experiments of 3D coupled simulations of fluid and heat transport. To assess the influence of the main faults bordering the graben on the hydraulic and the deep thermal field, we carried out a sensitivity analysis on fault width and permeability. Depending on the assigned width and permeability of the main border faults, fluid velocity and temperatures are affected only in the direct proximity of the respective border faults. Hence, the hydraulic characteristics of these major faults do not significantly influence the graben-wide groundwater flow patterns. Instead, the different scenarios tested provide a consistent image of the main characteristics of fluid and heat transport as they have in common: (1) a topography-driven basin-wide fluid flow perpendicular to the rift axis from the graben shoulders to the rift center, (2) a N/NE-directed flow parallel to the rift axis in the center of the rift and, (3) a pronounced upflow of hot fluids along the rift central axis, where the streams from both sides of the rift merge. This upflow axis is predicted to occur predominantly in the center of the URG (northern and southern model area) and shifted towards the eastern boundary fault (central model area).
Y1 - 2019
U6 - https://doi.org/10.1155/2019/7520714
SN - 1468-8115
SN - 1468-8123
PB - Wiley-Hindawi
CY - London
ER -
TY - JOUR
A1 - Vyse, Stuart Andrew
A1 - Semiromi, Majid Taie
A1 - Lischeid, Gunnar
A1 - Merz, Christoph
T1 - Characterizing hydrological processes within kettle holes using stable water isotopes in the Uckermark of northern Brandenburg, Germany
JF - Hydrological Processes
N2 - Understanding the hydrologic connectivity between kettle holes and shallow groundwater, particularly in reaction to the highly variable local meteorological conditions, is of paramount importance for tracing water in a hydro(geo)logically complex landscape and thus for integrated water resource management. This article is aimed at identifying the dominant hydrological processes affecting the kettle holes' water balance and their interactions with the shallow groundwater domain in the Uckermark region, located in the north-east of Germany. For this reason, based on the stable isotopes of oxygen (delta O-18) and hydrogen (delta H-2), an isotopic mass balance model was employed to compute the evaporative loss of water from the kettle holes from February to August 2017. Results demonstrated that shallow groundwater inflow may play the pivotal role in the processes taking part in the hydrology of the kettle holes in the Uckermark region. Based on the calculated evaporation/inflow (E/I) ratios, most of the kettle holes (86.7%) were ascertained to have a partially open, flow-through-dominated system. Moreover, we identified an inverse correlation between E/I ratios and the altitudes of the kettle holes. The same holds for electrical conductivity (EC) and the altitudes of the kettle holes. In accordance with the findings obtained from this study, a conceptual model explaining the interaction between the shallow groundwater and the kettle holes of Uckermark was developed. The model exhibited that across the highest altitudes, the recharge kettle holes are dominant, where a lower ratio of E/I and a lower EC was detected. By contrast, the lowest topographical depressions represent the discharge kettle holes, where a higher ratio of E/I and EC could be identified. The kettle holes existing in between were categorized as flow-through kettle holes through which the recharge takes place from one side and discharge from the other side.
KW - evaporation
KW - groundwater inflow
KW - kettle hole
KW - stable water isotope
KW - surface–groundwater interactions
Y1 - 2020
U6 - https://doi.org/10.1002/hyp.13699
SN - 0885-6087
SN - 1099-1085
VL - 34
IS - 8
SP - 1868
EP - 1887
PB - Wiley
CY - New York
ER -
TY - JOUR
A1 - Smetanová, Anna
A1 - Müller, Anne
A1 - Zargar, Morteza
A1 - Suleiman, Mohamed A.
A1 - Gholami, Faraz Rabei
A1 - Mousavi, Maryam
T1 - Mesoscale mapping of sediment source hotspots for dam sediment management in data-sparse semi-arid catchments
JF - Water
N2 - Land degradation and water availability in semi-arid regions are interdependent challenges for management that are influenced by climatic and anthropogenic changes. Erosion and high sediment loads in rivers cause reservoir siltation and decrease storage capacity, which pose risk on water security for citizens, agriculture, and industry. In regions where resources for management are limited, identifying spatial-temporal variability of sediment sources is crucial to decrease siltation. Despite widespread availability of rigorous methods, approaches simplifying spatial and temporal variability of erosion are often inappropriately applied to very data sparse semi-arid regions. In this work, we review existing approaches for mapping erosional hotspots, and provide an example of spatial-temporal mapping approach in two case study regions. The barriers limiting data availability and their effects on erosion mapping methods, their validation, and resulting prioritization of leverage management areas are discussed.
KW - reservoir siltation
KW - water security
KW - water management
KW - data sharing
KW - spatial-temporal
KW - erosion hotspots
KW - mapping
KW - global datasets
KW - mesoscale
KW - leverage areas
Y1 - 2020
U6 - https://doi.org/10.3390/w12020396
SN - 2073-4441
VL - 12
IS - 2
SP - 1
EP - 24
PB - MDPI
CY - Basel
ER -
TY - JOUR
A1 - Siegmund, Nicole
A1 - Panebianco, Juan E.
A1 - Avecilla, Fernando
A1 - Iturri, Laura Antonela
A1 - Sommer, Michael
A1 - Buschiazzo, Daniel
A1 - Funk, Roger
T1 - From gustiness to dustiness
BT - the impact of wind gusts on particulate matter emissions in field experiments in La Pampa, Argentina
JF - Atmosphere
N2 - This study delivers the first empirical data-driven analysis of the impact of turbulence induced gustiness on the fine dust emissions from a measuring field. For quantification of the gust impact, a new measure, the Gust uptake Efficiency (GuE) is introduced. GuE provides a percentage of over- or under-proportional dust uptake due to gust activity during a wind event. For the three analyzed wind events, GuE values of up to 150% could be found, yet they significantly differed per particle size class with a tendency for lower values for smaller particles. In addition, a high-resolution correlation analysis among 31 particle size classes and wind speed was conducted; it revealed strong negative correlation coefficients for very small particles and positive correlations for bigger particles, where 5 mu m appears to be an empirical threshold dividing both directions. We conclude with a number of suggestions for further investigations: an optimized field experiment setup, a new particle size ratio (PM1/PM0.5 in addition to PM10/PM2.5), as well as a comprehensive data-driven search for an optimal wind gust definition in terms of soil erosivity.
KW - wind gusts
KW - wind erosion
KW - particle uptake
KW - dust plumes
Y1 - 2022
U6 - https://doi.org/10.3390/atmos13081173
SN - 2073-4433
VL - 13
IS - 8
PB - MDPI
CY - Basel
ER -
TY - JOUR
A1 - Frieler, Katja
A1 - Schauberger, Bernhard
A1 - Arneth, Almut
A1 - Balkovic, Juraj
A1 - Chryssanthacopoulos, James
A1 - Deryng, Delphine
A1 - Elliott, Joshua
A1 - Folberth, Christian
A1 - Khabarov, Nikolay
A1 - Müller, Christoph
A1 - Olin, Stefan
A1 - Pugh, Thomas A. M.
A1 - Schaphoff, Sibyll
A1 - Schewe, Jacob
A1 - Schmid, Erwin
A1 - Warszawski, Lila
A1 - Levermann, Anders
T1 - Understanding the weather signal in national crop-yield variability
JF - Earths future
N2 - Year-to-year variations in crop yields can have major impacts on the livelihoods of subsistence farmers and may trigger significant global price fluctuations, with severe consequences for people in developing countries. Fluctuations can be induced by weather conditions, management decisions, weeds, diseases, and pests. Although an explicit quantification and deeper understanding of weather-induced crop-yield variability is essential for adaptation strategies, so far it has only been addressed by empirical models. Here, we provide conservative estimates of the fraction of reported national yield variabilities that can be attributed to weather by state-of-the-art, process-based crop model simulations. We find that observed weather variations can explain more than 50% of the variability in wheat yields in Australia, Canada, Spain, Hungary, and Romania. For maize, weather sensitivities exceed 50% in seven countries, including the United States. The explained variance exceeds 50% for rice in Japan and South Korea and for soy in Argentina. Avoiding water stress by simulating yields assuming full irrigation shows that water limitation is a major driver of the observed variations in most of these countries. Identifying the mechanisms leading to crop-yield fluctuations is not only fundamental for dampening fluctuations, but is also important in the context of the debate on the attribution of loss and damage to climate change. Since process-based crop models not only account for weather influences on crop yields, but also provide options to represent human-management measures, they could become essential tools for differentiating these drivers, and for exploring options to reduce future yield fluctuations.
Y1 - 2017
U6 - https://doi.org/10.1002/2016EF000525
SN - 2328-4277
VL - 5
SP - 605
EP - 616
PB - Wiley
CY - Hoboken
ER -
TY - JOUR
A1 - Schaller, Jörg
A1 - Puppe, Daniel
A1 - Kaczorek, Danuta
A1 - Ellerbrock, Ruth
A1 - Sommer, Michael
T1 - Silicon cycling in soils revisited
JF - Plants : open access journal
N2 - Silicon (Si) speciation and availability in soils is highly important for ecosystem functioning, because Si is a beneficial element for plant growth. Si chemistry is highly complex compared to other elements in soils, because Si reaction rates are relatively slow and dependent on Si species. Consequently, we review the occurrence of different Si species in soil solution and their changes by polymerization, depolymerization, and condensation in relation to important soil processes. We show that an argumentation based on thermodynamic endmembers of Si dependent processes, as currently done, is often difficult, because some reactions such as mineral crystallization require months to years (sometimes even centuries or millennia). Furthermore, we give an overview of Si reactions in soil solution and the predominance of certain solid compounds, which is a neglected but important parameter controlling the availability, reactivity, and function of Si in soils. We further discuss the drivers of soil Si cycling and how humans interfere with these processes. The soil Si cycle is of major importance for ecosystem functioning; therefore, a deeper understanding of drivers of Si cycling (e.g., predominant speciation), human disturbances and the implication for important soil properties (water storage, nutrient availability, and micro aggregate stability) is of fundamental relevance.
KW - andosols
KW - clay neoformation
KW - crop yield
KW - land use change
KW - micro
KW - aggregate stability
KW - phytoliths
KW - sediments
KW - silicon cycling
KW - silicon
KW - extraction methods
KW - silicon pore water speciation
Y1 - 2021
U6 - https://doi.org/10.3390/plants10020295
SN - 2223-7747
VL - 10
IS - 2
PB - MDPI
CY - Basel
ER -
TY - JOUR
A1 - Hoan, Tran Viet
A1 - Richter, Karl-Gerd
A1 - Borsig, Nicolas
A1 - Bauer, Jonas
A1 - Ha, Nguyen Thi
A1 - Norra, Stefan
T1 - An improved groundwater model framework for aquifer structures of the quaternary-formed sediment body in the southernmost parts of the Mekong Delta, Vietnam
JF - Hydrology : open access journal
N2 - The Ca Mau peninsula (CMP) is a key economic region in southern Vietnam. In recent decades, the high demand for water has increased the exploitation of groundwater, thus lowering the groundwater level and leading to risks of degradation, depletion, and land subsidence, as well as salinity intrusion in the groundwater of the whole Mekong Delta region. By using a finite element groundwater model with boundary expansion to the sea, we updated the latest data on hydrogeological profiles, groundwater levels, and exploitation. The basic model setup covers seven aquifers and seven aquitards. It is determined that the inflow along the coastline to the mainland is 39% of the total inflow. The exploitation of the study area in 2019 was 567,364 m(3)/day. The most exploited aquifers are the upper-middle Pleistocene (qp(2-3)) and the middle Pliocene (n(2)(2)), accounting for 63.7% and 24.6%, respectively; the least exploited aquifers are the upper Pleistocene and the upper Miocene, accounting for 0.35% and 0.02%, respectively. In the deeper aquifers, qp(2-3) and n(2)(2), the change in storage is negative due to the high exploitation rate, leading to a decline in the reserves of these aquifers. These groundwater model results are the calculations of groundwater reserves from the coast to the mainland in the entire system of aquifers in the CMP. This makes groundwater decision managers, stakeholders, and others more efficient in sustainable water resources planning in the CMP and Mekong Delta (MKD).
KW - groundwater modeling
KW - hydrogeology
KW - aquifers system
KW - water balance;
KW - validation of model
KW - Ca Mau peninsula
KW - Kien Giang
KW - Soc Trang
KW - Hau Giang
KW - Bac Lieu
Y1 - 2022
U6 - https://doi.org/10.3390/hydrology9040061
SN - 2306-5338
VL - 9
IS - 4
PB - MDPI
CY - Basel
ER -
TY - JOUR
A1 - Reinecke, Robert
A1 - Trautmann, Tim
A1 - Wagener, Thorsten
A1 - Schüler, Katja
T1 - The critical need to foster computational reproducibility
JF - Environmental research letters
KW - reproducibility
KW - models
KW - software
KW - Open Science
Y1 - 2022
U6 - https://doi.org/10.1088/1748-9326/ac5cf8
SN - 1748-9326
VL - 17
IS - 4
PB - IOP Publ. Ltd.
CY - Bristol
ER -
TY - JOUR
A1 - Didovets, Iulii
A1 - Krysanova, Valentina
A1 - Bürger, Gerd
A1 - Snizhko, Sergiy
A1 - Balabukh, Vira
A1 - Bronstert, Axel
T1 - Climate change impact on regional floods in the Carpathian region
JF - Journal of hydrology : Regional studies
N2 - Study region: Tisza and Prut catchments, originating on the slopes of the Carpathian mountains. Study focus: The study reported here investigates (i) climate change impacts on flood risk in the region, and (ii) uncertainty related to hydrological modelling, downscaling techniques and climate projections. The climate projections used in the study were derived from five GCMs, downscaled either dynamically with RCMs or with the statistical downscaling model XDS. The resulting climate change scenarios were applied to drive the eco-hydrological model SWIM, which was calibrated and validated for the catchments in advance using observed climate and hydrological data. The changes in the 30-year flood hazards and 98 and 95 percentiles of discharge were evaluated for the far future period (2071-2100) in comparison with the reference period (1981-2010). New hydrological insights for the region: The majority of model outputs under RCP 4.5 show a small to strong increase of the 30-year flood level in the Tisza ranging from 4.5% to 62%, and moderate increase in the Prut ranging from 11% to 22%. The impact results under RCP 8.5 are more uncertain with changes in both directions due to high uncertainties in GCM-RCM climate projections, downscaling methods and the low density of available climate stations.
KW - Climate change impact
KW - Floods
KW - Hydrological modelling
KW - SWIM
KW - Tisza
KW - Prut
KW - Carpathians
KW - Ukraine
Y1 - 2019
U6 - https://doi.org/10.1016/j.ejrh.2019.01.002
SN - 2214-5818
VL - 22
PB - Elsevier
CY - Amsterdam
ER -
TY - JOUR
A1 - Devitt, Laura
A1 - Neal, Jeffrey
A1 - Wagener, Thorsten
A1 - Coxon, Gemma
T1 - Uncertainty in the extreme flood magnitude estimates of large-scale flood hazard models
JF - Environmental research letters : ERL / Institute of Physics
N2 - The growing worldwide impact of flood events has motivated the development and application of global flood hazard models (GFHMs). These models have become useful tools for flood risk assessment and management, especially in regions where little local hazard information is available. One of the key uncertainties associated with GFHMs is the estimation of extreme flood magnitudes to generate flood hazard maps. In this study, the 1-in-100 year flood (Q100) magnitude was estimated using flow outputs from four global hydrological models (GHMs) and two global flood frequency analysis datasets for 1350 gauges across the conterminous US. The annual maximum flows of the observed and modelled timeseries of streamflow were bootstrapped to evaluate the sensitivity of the underlying data to extrapolation. Results show that there are clear spatial patterns of bias associated with each method. GHMs show a general tendency to overpredict Western US gauges and underpredict Eastern US gauges. The GloFAS and HYPE models underpredict Q100 by more than 25% in 68% and 52% of gauges, respectively. The PCR-GLOBWB and CaMa-Flood models overestimate Q100 by more than 25% at 60% and 65% of gauges in West and Central US, respectively. The global frequency analysis datasets have spatial variabilities that differ from the GHMs. We found that river basin area and topographic elevation explain some of the spatial variability in predictive performance found in this study. However, there is no single model or method that performs best everywhere, and therefore we recommend a weighted ensemble of predictions of extreme flood magnitudes should be used for large-scale flood hazard assessment.
KW - large-scale flood hazard models
KW - global hydrological model
KW - flood risk
Y1 - 2021
U6 - https://doi.org/10.1088/1748-9326/abfac4
SN - 1748-9326
VL - 16
IS - 6
PB - IOP Publ. Ltd.
CY - Bristol
ER -
TY - JOUR
A1 - Mtilatila, Lucy Mphatso Ng'ombe
A1 - Bronstert, Axel
A1 - Shrestha, Pallav
A1 - Kadewere, Peter
A1 - Vormoor, Klaus Josef
T1 - Susceptibility of water resources and hydropower production to climate change in the tropics
BT - the case of Lake Malawi and Shire River Basins, SE Africa
JF - Hydrology : open access journal
N2 - The sensitivity of key hydrologic variables and hydropower generation to climate change in the Lake Malawi and Shire River basins is assessed. The study adapts the mesoscale Hydrological Model (mHM) which is applied separately in the Upper Lake Malawi and Shire River basins. A particular Lake Malawi model, which focuses on reservoir routing and lake water balance, has been developed and is interlinked between the two basins. Climate change projections from 20 Coordinated Regional Climate Downscaling Experiment (CORDEX) models for Africa based on two scenarios (RCP4.5 and RCP8.5) for the periods 2021-2050 and 2071-2100 are used. An annual temperature increase of 1 degrees C decreases mean lake level and outflow by 0.3 m and 17%, respectively, signifying the importance of intensified evaporation for Lake Malawi's water budget. Meanwhile, a +5% (-5%) deviation in annual rainfall changes mean lake level by +0.7 m (-0.6 m). The combined effects of temperature increase and rainfall decrease result in significantly lower flows in the Shire River. The hydrological river regime may change from perennial to seasonal with the combination of annual temperature increase and precipitation decrease beyond 1.5 degrees C (3.5 degrees C) and -20% (-15%). The study further projects a reduction in annual hydropower production between 1% (RCP8.5) and 2.5% (RCP4.5) during 2021-2050 and between 5% (RCP4.5) and 24% (RCP8.5) during 2071-2100. The results show that it is of great importance that a further development of hydro energy on the Shire River should take into account the effects of climate change, e.g., longer low flow periods and/or higher discharge fluctuations, and thus uncertainty in the amount of electricity produced.
KW - Lake Malawi Basin
KW - Shire River Basin
KW - lake water balance
KW - climate change impacts in the tropics
KW - hydropower generation
KW - response surface analysis
KW - sensitivity analysis
Y1 - 2020
U6 - https://doi.org/10.3390/hydrology7030054
SN - 2306-5338
VL - 7
IS - 3
PB - MDPI
CY - Basel
ER -
TY - JOUR
A1 - Seleem, Omar
A1 - Ayzel, Georgy
A1 - Costa Tomaz de Souza, Arthur
A1 - Bronstert, Axel
A1 - Heistermann, Maik
T1 - Towards urban flood susceptibility mapping using data-driven models in Berlin, Germany
JF - Geomatics, natural hazards and risk
N2 - Identifying urban pluvial flood-prone areas is necessary but the application of two-dimensional hydrodynamic models is limited to small areas. Data-driven models have been showing their ability to map flood susceptibility but their application in urban pluvial flooding is still rare. A flood inventory (4333 flooded locations) and 11 factors which potentially indicate an increased hazard for pluvial flooding were used to implement convolutional neural network (CNN), artificial neural network (ANN), random forest (RF) and support vector machine (SVM) to: (1) Map flood susceptibility in Berlin at 30, 10, 5, and 2 m spatial resolutions. (2) Evaluate the trained models' transferability in space. (3) Estimate the most useful factors for flood susceptibility mapping. The models' performance was validated using the Kappa, and the area under the receiver operating characteristic curve (AUC). The results indicated that all models perform very well (minimum AUC = 0.87 for the testing dataset). The RF models outperformed all other models at all spatial resolutions and the RF model at 2 m spatial resolution was superior for the present flood inventory and predictor variables. The majority of the models had a moderate performance for predictions outside the training area based on Kappa evaluation (minimum AUC = 0.8). Aspect and altitude were the most influencing factors on the image-based and point-based models respectively. Data-driven models can be a reliable tool for urban pluvial flood susceptibility mapping wherever a reliable flood inventory is available.
KW - Urban pluvial flood susceptibility
KW - convolutional neural network
KW - deep
KW - learning
KW - random forest
KW - support vector machine
KW - spatial resolution;
KW - flood predictors
Y1 - 2022
U6 - https://doi.org/10.1080/19475705.2022.2097131
SN - 1947-5705
SN - 1947-5713
VL - 13
IS - 1
SP - 1640
EP - 1662
PB - Taylor & Francis
CY - London
ER -
TY - JOUR
A1 - Seleem, Omar
A1 - Ayzel, Georgy
A1 - Bronstert, Axel
A1 - Heistermann, Maik
T1 - Transferability of data-driven models to predict urban pluvial flood water depth in Berlin, Germany
JF - Natural Hazards and Earth System Sciences
N2 - Data-driven models have been recently suggested to surrogate computationally expensive hydrodynamic models to map flood hazards. However, most studies focused on developing models for the same area or the same precipitation event. It is thus not obvious how transferable the models are in space. This study evaluates the performance of a convolutional neural network (CNN) based on the U-Net architecture and the random forest (RF) algorithm to predict flood water depth, the models' transferability in space and performance improvement using transfer learning techniques. We used three study areas in Berlin to train, validate and test the models. The results showed that (1) the RF models outperformed the CNN models for predictions within the training domain, presumable at the cost of overfitting; (2) the CNN models had significantly higher potential than the RF models to generalize beyond the training domain; and (3) the CNN models could better benefit from transfer learning technique to boost their performance outside training domains than RF models.
Y1 - 2023
U6 - https://doi.org/10.5194/nhess-23-809-2023
SN - 1684-9981
SN - 1561-8633
VL - 23
IS - 2
SP - 809
EP - 822
PB - Copernicus
CY - Göttingen
ER -
TY - JOUR
A1 - Rottler, Erwin
A1 - Francke, Till
A1 - Bürger, Gerd
A1 - Bronstert, Axel
T1 - Long-term changes in central European river discharge for 1869–2016
BT - impact of changing snow covers, reservoir constructions and an intensified hydrological cycle
JF - Hydrology and Earth System Sciences
N2 - Recent climatic changes have the potential to severely alter river runoff, particularly in snow-dominated river basins. Effects of changing snow covers superimpose with changes in precipitation and anthropogenic modifications of the watershed and river network. In the attempt to identify and disentangle long-term effects of different mechanisms, we employ a set of analytical tools to extract long-term changes in river runoff at high resolution. We combine quantile sampling with moving average trend statistics and empirical mode decomposition and apply these tools to discharge data recorded along rivers with nival, pluvial and mixed flow regimes as well as temperature and precipitation data covering the time frame 1869-2016. With a focus on central Europe, we analyse the long-term impact of snow cover and precipitation changes along with their interaction with reservoir constructions.
Our results show that runoff seasonality of snow-dominated rivers decreases. Runoff increases in winter and spring, while discharge decreases in summer and at the beginning of autumn. We attribute this redistribution of annual flow mainly to reservoir constructions in the Alpine ridge. During the course of the last century, large fractions of the Alpine rivers were dammed to produce hydropower. In recent decades, runoff changes induced by reservoir constructions seem to overlap with changes in snow cover. We suggest that Alpine signals propagate downstream and affect runoff far outside the Alpine area in river segments with mixed flow regimes. Furthermore, our results hint at more (intense) rain-fall in recent decades. Detected increases in high discharge can be traced back to corresponding changes in precipitation.
KW - empirical mode decomposition
KW - atmospheric blocking
KW - heavy precipitation
KW - streamflow trends
KW - climate-change
KW - rhine basin
KW - time-series
KW - events
KW - Switzerland
KW - variability
Y1 - 2020
U6 - https://doi.org/10.5194/hess-24-1721-2020
SN - 1027-5606
SN - 1607-7938
VL - 24
IS - 4
SP - 1721
EP - 1740
PB - Copernicus
CY - Göttingen
ER -
TY - JOUR
A1 - Rottler, Erwin
A1 - Vormoor, Klaus Josef
A1 - Francke, Till
A1 - Warscher, Michael
A1 - Strasser, Ulrich
A1 - Bronstert, Axel
T1 - Elevation-dependent compensation effects in snowmelt in the Rhine River Basin upstream gauge Basel
JF - Hydrology research : an international journal / Nordic Association of Hydrology ; British Hydrological Society
N2 - In snow-dominated river basins, floods often occur during early summer, when snowmelt-induced runoff superimposes with rainfall-induced runoff. An earlier onset of seasonal snowmelt as a consequence of a warming climate is often expected to shift snowmelt contribution to river runoff and potential flooding to an earlier date. Against this background, we assess the impact of rising temperatures on seasonal snowpacks and quantify changes in timing, magnitude and elevation of snowmelt. We analyse in situ snow measurements, conduct snow simulations and examine changes in river runoff at key gauging stations. With regard to snowmelt, we detect a threefold effect of rising temperatures: snowmelt becomes weaker, occurs earlier and forms at higher elevations. Due to the wide range of elevations in the catchment, snowmelt does not occur simultaneously at all elevations. Results indicate that elevation bands melt together in blocks. We hypothesise that in a warmer world with similar sequences of weather conditions, snowmelt is moved upward to higher elevation. The movement upward the elevation range makes snowmelt in individual elevation bands occur earlier, although the timing of the snowmelt-induced runoff stays the same. Meltwater from higher elevations, at least partly, replaces meltwater from elevations below.
KW - compensation effects
KW - elevation-dependency
KW - Rhine River
KW - snowmelt
KW - timing
Y1 - 2021
U6 - https://doi.org/10.2166/nh.2021.092
SN - 2224-7955
VL - 52
IS - 2
SP - 536
EP - 557
PB - IWA Publ.
CY - London
ER -
TY - JOUR
A1 - Mtilatila, Lucy Mphatso Ng'ombe
A1 - Bronstert, Axel
A1 - Vormoor, Klaus Josef
T1 - Temporal evaluation and projections of meteorological droughts in the Greater Lake Malawi Basin, Southeast Africa
JF - Frontiers in water
N2 - The study examined the potential future changes of drought characteristics in the Greater Lake Malawi Basin in Southeast Africa. This region strongly depends on water resources to generate electricity and food. Future projections (considering both moderate and high emission scenarios) of temperature and precipitation from an ensemble of 16 bias-corrected climate model combinations were blended with a scenario-neutral response surface approach to analyses changes in: (i) the meteorological conditions, (ii) the meteorological water balance, and (iii) selected drought characteristics such as drought intensity, drought months, and drought events, which were derived from the Standardized Precipitation and Evapotranspiration Index. Changes were analyzed for a near-term (2021-2050) and far-term period (2071-2100) with reference to 1976-2005. The effect of bias-correction (i.e., empirical quantile mapping) on the ability of the climate model ensemble to reproduce observed drought characteristics as compared to raw climate projections was also investigated. Results suggest that the bias-correction improves the climate models in terms of reproducing temperature and precipitation statistics but not drought characteristics. Still, despite the differences in the internal structures and uncertainties that exist among the climate models, they all agree on an increase of meteorological droughts in the future in terms of higher drought intensity and longer events. Drought intensity is projected to increase between +25 and +50% during 2021-2050 and between +131 and +388% during 2071-2100. This translates into +3 to +5, and +7 to +8 more drought months per year during both periods, respectively. With longer lasting drought events, the number of drought events decreases. Projected droughts based on the high emission scenario are 1.7 times more severe than droughts based on the moderate scenario. That means that droughts in this region will likely become more severe in the coming decades. Despite the inherent high uncertainties of climate projections, the results provide a basis in planning and (water-)managing activities for climate change adaptation measures in Malawi. This is of particular relevance for water management issues referring hydro power generation and food production, both for rain-fed and irrigated agriculture.
KW - meteorological drought
KW - drought intensity
KW - climate change
KW - drought
KW - events
KW - Lake Malawi
KW - Shire River
KW - drought projections
KW - South-Eastern
KW - Africa
Y1 - 2022
U6 - https://doi.org/10.3389/frwa.2022.1041452
SN - 2624-9375
VL - 4
PB - Frontiers Media
CY - Lausanne
ER -
TY - JOUR
A1 - Seleem, Omar
A1 - Heistermann, Maik
A1 - Bronstert, Axel
T1 - Efficient Hazard Assessment For Pluvial Floods In Urban Environments
BT - A Benchmarking Case Study For The City Of Berlin, Germany
JF - Water
N2 - The presence of impermeable surfaces in urban areas hinders natural drainage and directs the surface runoff to storm drainage systems with finite capacity, which makes these areas prone to pluvial flooding. The occurrence of pluvial flooding depends on the existence of minimal areas for surface runoff generation and concentration. Detailed hydrologic and hydrodynamic simulations are computationally expensive and require intensive resources. This study compared and evaluated the performance of two simplified methods to identify urban pluvial flood-prone areas, namely the fill–spill–merge (FSM) method and the topographic wetness index (TWI) method and used the TELEMAC-2D hydrodynamic numerical model for benchmarking and validation. The FSM method uses common GIS operations to identify flood-prone depressions from a high-resolution digital elevation model (DEM). The TWI method employs the maximum likelihood method (MLE) to probabilistically calibrate a TWI threshold (τ) based on the inundation maps from a 2D hydrodynamic model for a given spatial window (W) within the urban area. We found that the FSM method clearly outperforms the TWI method both conceptually and effectively in terms of model performance.
KW - urban pluvial flooding
KW - digital elevation model (DEM)
KW - fill–spill–merge method
KW - topographic wetness index (TWI)
KW - TELEMAC-2D model
KW - flood-prone area
Y1 - 2021
U6 - https://doi.org/10.3390/w13182476
SN - 2073-4441
VL - 13
IS - 18
PB - MDPI
CY - Basel
ER -
TY - JOUR
A1 - Mtilatila, Lucy Mphatso Ng'ombe
A1 - Bronstert, Axel
A1 - Vormoor, Klaus Josef
T1 - Temporal evaluation and projections of meteorological droughts in the Greater Lake Malawi Basin, Southeast Africa
JF - Frontiers in Water
N2 - The study examined the potential future changes of drought characteristics in the Greater Lake Malawi Basin in Southeast Africa. This region strongly depends on water resources to generate electricity and food. Future projections (considering both moderate and high emission scenarios) of temperature and precipitation from an ensemble of 16 bias-corrected climate model combinations were blended with a scenario-neutral response surface approach to analyses changes in: (i) the meteorological conditions, (ii) the meteorological water balance, and (iii) selected drought characteristics such as drought intensity, drought months, and drought events, which were derived from the Standardized Precipitation and Evapotranspiration Index. Changes were analyzed for a near-term (2021–2050) and far-term period (2071–2100) with reference to 1976–2005. The effect of bias-correction (i.e., empirical quantile mapping) on the ability of the climate model ensemble to reproduce observed drought characteristics as compared to raw climate projections was also investigated. Results suggest that the bias-correction improves the climate models in terms of reproducing temperature and precipitation statistics but not drought characteristics. Still, despite the differences in the internal structures and uncertainties that exist among the climate models, they all agree on an increase of meteorological droughts in the future in terms of higher drought intensity and longer events. Drought intensity is projected to increase between +25 and +50% during 2021–2050 and between +131 and +388% during 2071–2100. This translates into +3 to +5, and +7 to +8 more drought months per year during both periods, respectively. With longer lasting drought events, the number of drought events decreases. Projected droughts based on the high emission scenario are 1.7 times more severe than droughts based on the moderate scenario. That means that droughts in this region will likely become more severe in the coming decades. Despite the inherent high uncertainties of climate projections, the results provide a basis in planning and (water-)managing activities for climate change adaptation measures in Malawi. This is of particular relevance for water management issues referring hydro power generation and food production, both for rain-fed and irrigated agriculture.
KW - meteorological drought
KW - drought intensity
KW - climate change
KW - drought events
KW - Lake Malawi
KW - Shire River
KW - drought projections
KW - South-Eastern Africa
Y1 - 2022
U6 - https://doi.org/10.3389/frwa.2022.1041452
SN - 2624-9375
SP - 1
EP - 16
PB - Frontiers Media S.A.
CY - Lausanne, Schweiz
ER -
TY - JOUR
A1 - Bryant, Seth
A1 - McGrath, Heather
A1 - Boudreault, Mathieu
T1 - Gridded flood depth estimates from satellite-derived inundations
JF - Natural hazards and earth system sciences
N2 - Canada's RADARSAT missions improve the potential to study past flood events; however, existing tools to derive flood depths from this remote-sensing data do not correct for errors, leading to poor estimates.
To provide more accurate gridded depth estimates of historical flooding, a new tool is proposed that integrates Height Above Nearest Drainage and Cost Allocation algorithms. This tool is tested against two trusted, hydraulically derived, gridded depths of recent floods in Canada.
This validation shows the proposed tool outperforms existing tools and can provide more accurate estimates from minimal data without the need for complex physics-based models or expert judgement.
With improvements in remote-sensing data, the tool proposed here can provide flood researchers and emergency managers accurate depths in near-real time.
Y1 - 2022
U6 - https://doi.org/10.5194/nhess-22-1437-2022
SN - 1561-8633
SN - 1684-9981
VL - 22
IS - 4
SP - 1437
EP - 1450
PB - European Geophysical Society
CY - Katlenburg-Lindau
ER -
TY - JOUR
A1 - Kühn, Elisabeth
A1 - Becker, Marc
A1 - Harpke, Alexander
A1 - Kühn, Ingolf
A1 - Kuhlicke, Christian
A1 - Schmitt, Thomas
A1 - Settele, Josef
A1 - Musche, Martin
T1 - The benefits of counting butterflies: recommendations for a successful citizen science project
JF - Ecology and Society
N2 - Citizen science (CS) projects, being popular across many fields of science, have recently also become a popular tool to collect biodiversity data. Although the benefits of such projects for science and policy making are well understood, relatively little is known about the benefits participants get from these projects as well as their personal backgrounds and motivations. Furthermore, very little is known about their expectations. We here examine these aspects, with the citizen science project "German Butterfly Monitoring" as an example. A questionnaire was sent to all participants of the project and the responses to the questionnaire indicated the following: center dot Most transect walkers do not have a professional background in this field, though they do have a high educational level, and are close to retirement, with a high number of females; center dot An important motivation to join the project is to preserve the natural environment and to contribute to scientific knowledge; center dot Participants benefit by enhancing their knowledge about butterflies and especially their ability to identify different species (taxonomic knowledge); center dot Participants do not have specific expectations regarding the project beyond proper management and coordination, but have an intrinsic sense of working for a greater good. The willingness to join a project is higher if the project contributes to the solution of a problem discussed in the media (here, insect decline). Based on our findings from the analysis of the questionnaire we can derive a set of recommendations for establishing a successful CS project. These include the importance of good communication, e.g., by explaining what the (scientific) purpose of the project is and what problems are to be solved with the help of the data collected in the project. The motivation to join a CS project is mostly intrinsic and CS is a good tool to engage people during difficult times such as the COVID-19 pandemic, giving participants the feeling of doing something useful.
KW - COVID-19 pandemic
KW - gender gap
KW - insect decline
KW - intrinsic motivation
KW - monitoring
Y1 - 2022
U6 - https://doi.org/10.5751/ES-12861-270238
SN - 1708-3087
VL - 27
IS - 2
PB - Resilience Alliance
CY - Wolfville
ER -
TY - JOUR
A1 - Vogel, Johannes
A1 - Paton, Eva
A1 - Aich, Valentin
A1 - Bronstert, Axel
T1 - Increasing compound warm spells and droughts in the Mediterranean Basin
JF - Weather and climate extremes
N2 - The co-occurrence of warm spells and droughts can lead to detrimental socio-economic and ecological impacts, largely surpassing the impacts of either warm spells or droughts alone. We quantify changes in the number of compound warm spells and droughts from 1979 to 2018 in the Mediterranean Basin using the ERA5 data set. We analyse two types of compound events: 1) warm season compound events, which are extreme in absolute terms in the warm season from May to October and 2) year-round deseasonalised compound events, which are extreme in relative terms respective to the time of the year. The number of compound events increases significantly and especially warm spells are increasing strongly – with an annual growth rates of 3.9 (3.5) % for warm season (deseasonalised) compound events and 4.6 (4.4) % for warm spells –, whereas for droughts the change is more ambiguous depending on the applied definition. Therefore, the rise in the number of compound events is primarily driven by temperature changes and not the lack of precipitation. The months July and August show the highest increases in warm season compound events, whereas the highest increases of deseasonalised compound events occur in spring and early summer. This increase in deseasonalised compound events can potentially have a significant impact on the functioning of Mediterranean ecosystems as this is the peak phase of ecosystem productivity and a vital phenophase.
KW - Compound events
KW - Warm spells
KW - Droughts
KW - Mediterranean basin
KW - Extreme events
KW - Climate change
Y1 - 2021
U6 - https://doi.org/10.1016/j.wace.2021.100312
SN - 2212-0947
VL - 32
PB - Elsevier
CY - Amsterdam
ER -
TY - JOUR
A1 - Bürger, Gerd
A1 - Pfister, Angela
A1 - Bronstert, Axel
T1 - Zunehmende Starkregenintensitäten als Folge der Klimaerwärmung
T1 - Increasing intensity of heavy rainfall caused by global warming
BT - Datenanalyse und Zukunftsprojektion
BT - data analysis and future projections
JF - Hydrologie und Wasserbewirtschaftung : HyWa = Hydrology and water resources management, Germany / Hrsg.: Fachverwaltungen des Bundes und der Länder
N2 - Extreme rainfall events of short duration in the range of hours and below are increasingly coming into focus due to the resulting damage from flash floods and also due to their possible intensification by anthropogenic climate change. The current study investigates possible trends in heavy rainfall intensities for stations from Swiss and Austrian alpine regions as well as for the Emscher-Lippe area in North Rhine-Westphalia on the basis of partly very long (> 50 years) and temporally highly resolved time series (<= 15 minutes). It becomes clear that there is an increase in extreme rainfall intensities, which can be well explained by the warming of the regional climate: the analyses of long-term trends in exceedance counts and return levels show considerable uncertainties, but are in the order of 30 % increase per century. In addition, based on an "average" climate simulation for the 21st century, this paper describes a projection for extreme precipitation intensities at very high temporal resolution for a number of stations in the Emscher-Lippe region. A coupled spatial and temporal "downscaling" is applied, the key innovation of which is the consideration of the dependence of local rainfall intensity on air temperature. This procedure involves two steps: First, large-scale climate fields at daily resolution are statistically linked by regression to station temperature and precipitation values (spatial downscaling). In the second step, these station values are disaggregated to a temporal resolution of 10 minutes using a so-called multiplicative stochastic cascade model (MC) (temporal downscaling). The novel, temperature-sensitive variant additionally considers air temperature as an explanatory variable for precipitation intensities. Thus, the higher atmospheric moisture content expected with warming, which results from the Clausius-Clapeyron (CC) relationship, is included in the temporal downscaling.
For the statistical evaluation of the extreme short-term precipitation, the upper quantiles (99.9 %), exceedance counts (P > 5mm), and 3-yr return levels of the <= 15-min duration step has been used. Only by adding temperature is the observed temperature observed of the extreme quantiles ("CC scaling") well reproduced. When comparing observed data and present-day simulations of the model cascade, the temperature-sensitive procedure shows consistent results. Compared to trends in recent decades, similar or even larger increases in extreme intensities are projected for the future. This is remarkable in that these appear to be driven primarily by local temperature, as the projected trends in daily precipitation values are negligible for this region.
N2 - Extreme Regenereignisse von kurzer Dauer im Bereich von Stunden und darunter rücken aufgrund der dadurch bedingten Schäden durch Sturzfluten und auch wegen ihrer möglichen Intensivierungen durch den anthropogenen Klimawandel immer stärker in den Fokus. Die vorliegende Studie untersucht auf Basis von teilweise sehr langen (> 50 Jahre) und zeitlich hochaufgelösten Zeitreihen (≤ 15 Minuten) mögliche Trends in Starkregenintensitäten für Stationen aus schweizerischen und österreichischen Alpenregionen sowie für das Emscher-Lippe-Gebiet in Nordrhein-Westfalen. Es wird deutlich, dass es eine Zunahme der extremen Niederschlagsintensitäten gibt, welche gut durch die Erwärmung des regionalen Klimas erklärt werden kann: Die Analysen langfristiger Trends der Überschreitungssummen und Wiederkehrniveaus zeigen zwar erhebliche Unsicherheiten, lassen jedoch eine Zunahme in einer Größenordnung von 30 % pro Jahrhundert erkennen. Zudem wird in diesem Beitrag, basierend auf einer "mittleren" Klimasimulation für das 21. Jahrhundert, für ausgewählte Stationen der Emscher-Lippe-Region eine Projektion für extreme Niederschlagsintensitäten in sehr hoher zeitlicher Auflösung beschrieben. Dabei wird ein gekoppeltes räumliches und zeitliches "Downscaling" angewendet, dessen entscheidende Neuerung die Berücksichtigung der Abhängigkeit der lokalen Regenintensität von der Lufttemperatur ist. Dieses Verfahren beinhaltet zwei Schritte: Zuerst werden großräumige Klimafelder in täglicher Auflösung durch Regression mit den Temperatur- und Niederschlagswerten der Stationen statistisch verbunden (räumliches Downscaling). Im zweiten Schritt werden dann diese Stationswerte mithilfe eines sogenannten multiplikativen stochastischen Kaskadenmodells (MC) auf eine zeitliche Auflösung von 10 Minuten disaggregiert (zeitliches Downscaling). Die neuartige, temperatursensitive Variante berücksichtigt zusätzlich die Lufttemperatur als erklärende Variable für die Niederschlagsintensitäten. Dadurch wird der mit einer Erwärmung zu erwartende höhere atmosphärische Feuchtegehalt, welcher sich aus der Clausius-Clapeyron-Beziehung (CC) ergibt, mit in das zeitliche Downscaling einbezogen.
Für die statistische Auswertung der extremen kurzfristigen Niederschläge wurden die oberen Quantile (99,9 %), Überschreitungssummen (ÜS, P > 5 mm) und 3-jährliche Wiederkehrniveaus (WN) einer Dauerstufe von ≤ 15-Minuten betrachtet. Diese Auswahl erlaubt die gleichzeitige Analyse sowohl von Extremwertstatistiken als auch von deren langfristigen Trends; leichte Abweichungen von dieser Wahl beeinflussen die Hauptergebnisse nur unwesentlich. Nur durch die Hinzunahme der Temperatur wird die beobachtete Temperaturabhängigkeit der extremen Quantile (CC-Scaling) gut wiedergegeben. Bei Vergleich von Beobachtungsdaten und Gegenwartssimulationen der Modellkaskade zeigt das temperatursensitive Verfahren konsistente Ergebnisse. Im Vergleich zu den Entwicklungen der letzten Jahrzehnte werden für die Zukunft ähnliche oder sogar noch stärkere Anstiege der extremen Niederschlagsintensitäten projiziert. Dies ist insofern bemerkenswert, als diese anscheinend hauptsächlich durch die örtliche Temperatur bestimmt werden, denn die projizierten Trends der Niederschlags-Tageswerte sind für diese Region vernachlässigbar.
KW - heavy rainfall
KW - short duration
KW - global warming
KW - Clausius-Clapeyron
KW - equation
KW - precipitation intensity
KW - multiplicative cascade model
KW - Strakregen
KW - kurzfristige Dauerstufe
KW - Klimawandel
KW - Clausius-Clapeyron-Gleichung
KW - Niederschlagsintensitäten
KW - Multiplikatives Kaskadenmodel
Y1 - 2021
U6 - https://doi.org/10.5675/HyWa_2021.6_1
SN - 1439-1783
SN - 2749-859X
VL - 65
IS - 6
SP - 262
EP - 271
PB - Bundesanst. für Gewässerkunde
CY - Koblenz
ER -
TY - JOUR
A1 - von Specht, Sebastian
A1 - Öztürk, Ugur
A1 - Veh, Georg
A1 - Cotton, Fabrice
A1 - Korup, Oliver
T1 - Effects of finite source rupture on landslide triggering
BT - the 2016 M-w 7.1 Kumamoto earthquake
JF - Solid earth
N2 - The propagation of a seismic rupture on a fault introduces spatial variations in the seismic wave field surrounding the fault. This directivity effect results in larger shaking amplitudes in the rupture propagation direction. Its seismic radiation pattern also causes amplitude variations between the strike-normal and strike-parallel components of horizontal ground motion. We investigated the landslide response to these effects during the 2016 Kumamoto earthquake (M-w 7.1) in central Kyushu (Japan). Although the distribution of some 1500 earthquake-triggered landslides as a function of rupture distance is consistent with the observed Arias intensity, the landslides were more concentrated to the northeast of the southwest-northeast striking rupture. We examined several landslide susceptibility factors: hillslope inclination, the median amplification factor (MAF) of ground shaking, lithology, land cover, and topographic wetness. None of these factors sufficiently explains the landslide distribution or orientation (aspect), although the landslide head scarps have an elevated hillslope inclination and MAF. We propose a new physics-based ground-motion model (GMM) that accounts for the seismic rupture effects, and we demonstrate that the low-frequency seismic radiation pattern is consistent with the overall landslide distribution. Its spatial pattern is influenced by the rupture directivity effect, whereas landslide aspect is influenced by amplitude variations between the fault-normal and fault-parallel motion at frequencies < 2 Hz. This azimuth dependence implies that comparable landslide concentrations can occur at different distances from the rupture. This quantitative link between the prevalent landslide aspect and the low-frequency seismic radiation pattern can improve coseismic landslide hazard assessment.
Y1 - 2019
U6 - https://doi.org/10.5194/se-10-463-2019
SN - 1869-9510
SN - 1869-9529
VL - 10
IS - 2
SP - 463
EP - 486
PB - Copernicus
CY - Göttingen
ER -
TY - JOUR
A1 - Ritter, Christoph
A1 - Ángeles Burgos, María
A1 - Böckmann, Christine
A1 - Mateos, David
A1 - Lisok, Justyna
A1 - Markowicz, Krzysztof M.
A1 - Moroni, Beatrice
A1 - Cappelletti, David
A1 - Udisti, Roberto
A1 - Maturilli, Marion
A1 - Neuber, Roland
T1 - Microphysical properties and radiative impact of an intense biomass burning aerosol event measured over Ny-angstrom lesund, Spitsbergen in July 2015
JF - Tellus - Series B, Chemical and Physical Meteorology
N2 - In this work, an evaluation of an intense biomass burning event observed over Ny-angstrom lesund (Spitsbergen, European Arctic) in July 2015 is presented. Data from the multi-wavelengths Raman-lidar KARL, a sun photometer and radiosonde measurements are used to derive some microphysical properties of the biomass burning aerosol as size distribution, refractive index and single scattering albedo at different relative humidities. Predominantly particles in the accumulation mode have been found with a bi-modal distribution and dominance of the smaller mode. Above 80% relative humidity, hygroscopic growth in terms of an increase of particle diameter and a slight decrease of the index of refraction (real and imaginary part) has been found. Values of the single scattering albedo around 0.9 both at 355nm and 532nm indicate some absorption by the aerosol. Values of the lidar ratio are around 26sr for 355nm and around 50sr for 532nm, almost independent of the relative humidity. Further, data from the photometer and surface radiation values from the local baseline surface radiation network (BSRN) have been applied to derive the radiative impact of the biomass burning event purely from observational data by comparison with a clear background day. We found a strong cooling for the visible radiation and a slight warming in the infra-red. The net aerosol forcing, derived by comparison with a clear background day purely from observational data, obtained a value of -95 W/m(2) per unit AOD500.
KW - aerosol
KW - lidar
KW - retrieval of aerosol properties
KW - radiative forcing
KW - Arctic aerosol
Y1 - 2018
U6 - https://doi.org/10.1080/16000889.2018.1539618
SN - 1600-0889
VL - 70
PB - Routledge, Taylor & Francis Group
CY - Abingdon
ER -
TY - JOUR
A1 - Schweppe, Robert
A1 - Thober, Stephan
A1 - Müller, Sebastian
A1 - Kelbling, Matthias
A1 - Kumar, Rohini
A1 - Attinger, Sabine
A1 - Samaniego, Luis
T1 - MPR 1.0: a stand-alone multiscale parameter regionalization tool for improved parameter estimation of land surface models
JF - Geoscientific model development : an interactive open access journal of the European Geosciences Union
N2 - Distributed environmental models such as land surface models (LSMs) require model parameters in each spatial modeling unit (e.g., grid cell), thereby leading to a high-dimensional parameter space. One approach to decrease the dimensionality of the parameter space in these models is to use regularization techniques. One such highly efficient technique is the multiscale parameter regionalization (MPR) framework that translates high-resolution predictor variables (e.g., soil textural properties) into model parameters (e.g., porosity) via transfer functions (TFs) and upscaling operators that are suitable for every modeled process. This framework yields seamless model parameters at multiple scales and locations in an effective manner. However, integration of MPR into existing modeling workflows has been hindered thus far by hard-coded configurations and non-modular software designs. For these reasons, we redesigned MPR as a model-agnostic, stand-alone tool. It is a useful software for creating graphs of NetCDF variables, wherein each node is a variable and the links consist of TFs and/or upscaling operators. In this study, we present and verify our tool against a previous version, which was implemented in the mesoscale hydrologic model (mHM; https://www.ufz.de/mhm, last access: 16 January 2022). By using this tool for the generation of continental-scale soil hydraulic parameters applicable to different models (Noah-MP and HTESSEL), we showcase its general functionality and flexibility. Further, using model parameters estimated by the MPR tool leads to significant changes in long-term estimates of evapotranspiration, as compared to their default parameterizations. For example, a change of up to 25 % in long-term evapotranspiration flux is observed in Noah-MP and HTESSEL in the Mississippi River basin. We postulate that use of the stand-alone MPR tool will considerably increase the transparency and reproducibility of the parameter estimation process in distributed (environmental) models. It will also allow a rigorous uncertainty estimation related to the errors of the predictors (e.g., soil texture fields), transfer function and its parameters, and remapping (or upscaling) algorithms.
Y1 - 2022
U6 - https://doi.org/10.5194/gmd-15-859-2022
SN - 1991-959X
SN - 1991-9603
VL - 15
IS - 2
SP - 859
EP - 882
PB - Copernicus
CY - Göttingen
ER -
TY - JOUR
A1 - Funk, Roger
A1 - Busse, Jaqueline
A1 - Siegmund, Nicole
A1 - Sommer, Michael
A1 - Iturri, Laura Antonela
A1 - Panebianco, Juan E.
A1 - Avecilla, Fernando
A1 - Buschiazzo, Daniel
T1 - Phytoliths in particulate matter released by wind erosion on arable land in La Pampa, Argentina
JF - Frontiers in environmental science
N2 - Silicon (Si) is considered a beneficial element in plant nutrition, but its importance on ecosystems goes far beyond that. Various forms of silicon are found in soils, of which the phytogenic pool plays a decisive role due to its good availability. This Si returns to the soil through the decomposition of plant residues, where they then participate in the further cycle as biogenic amorphous silica (bASi) or so-called phytoliths. These have a high affinity for water, so that the water holding capacity and water availability of soils can be increased even by small amounts of ASi. Agricultural land is a considerable global dust source, and dust samples from arable land have shown in cloud formation experiments a several times higher ice nucleation activity than pure mineral dust. Here, particle sizes in the particulate matter fractions (PM) are important, which can travel long distances and reach high altitudes in the atmosphere. Based on this, the research question was whether phytoliths could be detected in PM samples from wind erosion events, what are the main particle sizes of phytoliths and whether an initial quantification was possible.Measurements of PM concentrations were carried out at a wind erosion measuring field in the province La Pampa, Argentina. PM were sampled during five erosion events with Environmental Dust Monitors (EDM). After counting and classifying all particles with diameters between 0.3 and 32 mu m in the EDMs, they are collected on filters. The filters were analyzed by Scanning Electron Microscopy and Energy Dispersive X-Ray analysis (SEM-EDX) to investigate single or ensembles of particles regarding composition and possible origins.The analyses showed up to 8.3 per cent being phytoliths in the emitted dust and up to 25 per cent of organic origin. Particles of organic origin are mostly in the coarse dust fraction, whereas phytoliths are predominately transported in the finer dust fractions. Since phytoliths are both an important source of Si as a plant nutrient and are also involved in soil C fixation, their losses from arable land via dust emissions should be considered and its specific influence on atmospheric processes should be studied in detail in the future.
KW - dust
KW - dust composition
KW - particulate matter
KW - scanning electron microscope
KW - (SEM) analysis
KW - phytolith
Y1 - 2022
U6 - https://doi.org/10.3389/fenvs.2022.969898
SN - 2296-665X
VL - 10
PB - Frontiers Media
CY - Lausanne
ER -
TY - JOUR
A1 - Haber-Pohlmeier, Sabina
A1 - Tötzke, Christian
A1 - Lehmann, E.
A1 - Kardjilov, Nikolay
A1 - Pohlmeier, A.
A1 - Oswald, Sascha
T1 - Combination of magnetic resonance imaging and neutron computed tomography for three-dimensional rhizosphere imaging
JF - Vadose zone journal
N2 - Core Ideas
3D MRI relaxation time maps reflect water mobility in root, rhizosphere, and soil.
3D NCT water content maps of the same plant complement relaxation time maps.
The relaxation time T1 decreases from soil to root, whereas water content increases.
Parameters together indicate modification of rhizosphere pore space by gel phase.
The zone of reduced T1 corresponds to the zone remaining dry after rewetting.
In situ investigations of the rhizosphere require high‐resolution imaging techniques, which allow a look into the optically opaque soil compartment. We present the novel combination of magnetic resonance imaging (MRI) and neutron computed tomography (NCT) to achieve synergistic information such as water mobility in terms of three‐dimensional (3D) relaxation time maps and total water content maps. Besides a stationary MRI scanner for relaxation time mapping, we used a transportable MRI system on site in the NCT facility to capture rhizosphere properties before desiccation and after subsequent rewetting. First, we addressed two questions using water‐filled test capillaries between 0.1 and 5 mm: which root diameters can still be detected by both methods, and to what extent are defined interfaces blurred by these imaging techniques? Going to real root system architecture, we demonstrated the sensitivity of the transportable MRI device by co‐registration with NCT and additional validation using X‐ray computed tomography. Under saturated conditions, we observed for the rhizosphere in situ a zone with shorter T1 relaxation time across a distance of about 1 mm that was not caused by reduced water content, as proven by successive NCT measurements. We conclude that the effective pore size in the pore network had changed, induced by a gel phase. After rewetting, NCT images showed a dry zone persisting while the MRI intensity inside the root increased considerably, indicating water uptake from the surrounding bulk soil through the still hydrophobic rhizosphere. Overall, combining NCT and MRI allows a more detailed analysis of the rhizosphere's functioning.
Y1 - 2019
U6 - https://doi.org/10.2136/vzj2018.09.0166
SN - 1539-1663
VL - 18
IS - 1
PB - Soil Science Society of America
CY - Madison
ER -
TY - JOUR
A1 - Tötzke, Christian
A1 - Kardjilov, Nikolay
A1 - Hilger, André
A1 - Rudolph-Mohr, Nicole
A1 - Manke, Ingo
A1 - Oswald, Sascha
T1 - Three-dimensional in vivo analysis of water uptake and translocation in maize roots by fast neutron tomography
JF - Scientific Reports
N2 - Root water uptake is an essential process for terrestrial plants that strongly affects the spatiotemporal distribution of water in vegetated soil. Fast neutron tomography is a recently established non-invasive imaging technique capable to capture the 3D architecture of root systems in situ and even allows for tracking of three-dimensional water flow in soil and roots. We present an in vivo analysis of local water uptake and transport by roots of soil-grown maize plants—for the first time measured in a three-dimensional time-resolved manner. Using deuterated water as tracer in infiltration experiments, we visualized soil imbibition, local root uptake, and tracked the transport of deuterated water throughout the fibrous root system for a day and night situation. This revealed significant differences in water transport between different root types. The primary root was the preferred water transport path in the 13-days-old plants while seminal roots of comparable size and length contributed little to plant water supply. The results underline the unique potential of fast neutron tomography to provide time-resolved 3D in vivo information on the water uptake and transport dynamics of plant root systems, thus contributing to a better understanding of the complex interactions of plant, soil and water.
KW - Environmental sciences
KW - Optics and photonics
KW - Plant sciences
Y1 - 2021
U6 - https://doi.org/10.1038/s41598-021-90062-4
SN - 2045-2322
VL - 11
PB - Macmillan Publishers Limited
CY - London
ER -
TY - JOUR
A1 - Francke, Till
A1 - Heistermann, Maik
A1 - Köhli, Markus
A1 - Budach, Christian
A1 - Schrön, Martin
A1 - Oswald, Sascha
T1 - Assessing the feasibility of a directional cosmic-ray neutron sensing sensor for estimating soil moisture
JF - Geoscientific Instrumentation, Methods and Data Systems
N2 - Cosmic-ray neutron sensing (CRNS) is a non-invasive tool for measuring hydrogen pools such as soil moisture, snow or vegetation. The intrinsic integration over a radial hectare-scale footprint is a clear advantage for averaging out small-scale heterogeneity, but on the other hand the data may become hard to interpret in complex terrain with patchy land use.
This study presents a directional shielding approach to prevent neutrons from certain angles from being counted while counting neutrons entering the detector from other angles and explores its potential to gain a sharper horizontal view on the surrounding soil moisture distribution.
Using the Monte Carlo code URANOS (Ultra Rapid Neutron-Only Simulation), we modelled the effect of additional polyethylene shields on the horizontal field of view and assessed its impact on the epithermal count rate, propagated uncertainties and aggregation time.
The results demonstrate that directional CRNS measurements are strongly dominated by isotropic neutron transport, which dilutes the signal of the targeted direction especially from the far field. For typical count rates of customary CRNS stations, directional shielding of half-spaces could not lead to acceptable precision at a daily time resolution. However, the mere statistical distinction of two rates should be feasible.
KW - water-balance
KW - quantification
KW - calibration
KW - validation
Y1 - 2021
U6 - https://doi.org/10.5194/gi-11-75-2022
SN - 2193-0864
SN - 2193-0856
VL - 11
SP - 75
EP - 92
PB - Copernicus Publ.
CY - Göttingen
ER -
TY - JOUR
A1 - Heistermann, Maik
A1 - Francke, Till
A1 - Schrön, Martin
A1 - Oswald, Sascha
T1 - Spatio-temporal soil moisture retrieval at the catchment scale using a dense network of cosmic-ray neutron sensors
JF - Hydrology and Earth System Sciences (HESS)
N2 - Cosmic-ray neutron sensing (CRNS) is a powerful technique for retrieving representative estimates of soil water content at a horizontal scale of hectometres (the “field scale”) and depths of tens of centimetres (“the root zone”). This study demonstrates the potential of the CRNS technique to obtain spatio-temporal patterns of soil moisture beyond the integrated volume from isolated CRNS footprints. We use data from an observational campaign carried out between May and July 2019 that featured a dense network of more than 20 neutron detectors with partly overlapping footprints in an area that exhibits pronounced soil moisture gradients within one square kilometre. The present study is the first to combine these observations in order to represent the heterogeneity of soil water content at the sub-footprint scale as well as between the CRNS stations. First, we apply a state-of-the-art procedure to correct the observed neutron count rates for static effects (heterogeneity in space, e.g. soil organic matter) and dynamic effects (heterogeneity in time, e.g. barometric pressure). Based on the homogenized neutron data, we investigate the robustness of a calibration approach that uses a single calibration parameter across all CRNS stations. Finally, we benchmark two different interpolation techniques for obtaining spatio-temporal representations of soil moisture: first, ordinary Kriging with a fixed range; second, spatial interpolation complemented by geophysical inversion (“constrained interpolation”). To that end, we optimize the parameters of a geostatistical interpolation model so that the error in the forward-simulated neutron count rates is minimized, and suggest a heuristic forward operator to make the optimization problem computationally feasible. Comparison with independent measurements from a cluster of soil moisture sensors (SoilNet) shows that the constrained interpolation approach is superior for representing horizontal soil moisture gradients at the hectometre scale. The study demonstrates how a CRNS network can be used to generate coherent, consistent, and continuous soil moisture patterns that could be used to validate hydrological models or remote sensing products.
Y1 - 2021
U6 - https://doi.org/10.5194/hess-25-4807-2021
SN - 1607-7938
VL - 25
PB - Copernicus Publications
CY - Göttingen
ER -
TY - JOUR
A1 - Pánek, Tomáš
A1 - Břežný, Michal
A1 - Harrison, Stephan
A1 - Schönfeldt, Elisabeth
A1 - Winocur, Diego
T1 - Large landslides cluster at the margin of a deglaciated mountain belt
JF - Scientific reports
N2 - Landslides in deglaciated and deglaciating mountains represent a major hazard, but their distribution at the spatial scale of entire mountain belts has rarely been studied. Traditional models of landslide distribution assume that landslides are concentrated in the steepest, wettest, and most tectonically active parts of the orogens, where glaciers reached their greatest thickness.
However, based on mapping large landslides (>0.9 km(2)) over an unprecedentedly large area of Southern Patagonia (similar to 305,000 km(2)), we show that the distribution of landslides can have the opposite trend.
We show that the largest landslides within the limits of the former Patagonian Ice Sheet (PIS) cluster along its eastern margins occupying lower, tectonically less active, and arid part of the Patagonian Andes. In contrast to the heavily glaciated, highest elevations of the mountain range, the peripheral regions have been glaciated only episodically, leaving a larger volume of unstable sedimentary and volcanic rocks that are subject to ongoing slope instability.
Y1 - 2022
U6 - https://doi.org/10.1038/s41598-022-09357-9
SN - 2045-2322
VL - 12
IS - 1
PB - Macmillan Publishers Limited, part of Springer Nature
CY - London
ER -
TY - JOUR
A1 - Metin, Ayse Duha
A1 - Nguyen Viet Dung,
A1 - Schröter, Kai
A1 - Guse, Björn
A1 - Apel, Heiko
A1 - Kreibich, Heidi
A1 - Vorogushyn, Sergiy
A1 - Merz, Bruno
T1 - How do changes along the risk chain affect flood risk?
JF - Natural hazards and earth system sciences
N2 - Flood risk is impacted by a range of physical and socio-economic processes. Hence, the quantification of flood risk ideally considers the complete flood risk chain, from atmospheric processes through catchment and river system processes to damage mechanisms in the affected areas. Although it is generally accepted that a multitude of changes along the risk chain can occur and impact flood risk, there is a lack of knowledge of how and to what extent changes in influencing factors propagate through the chain and finally affect flood risk. To fill this gap, we present a comprehensive sensitivity analysis which considers changes in all risk components, i.e. changes in climate, catchment, river system, land use, assets, and vulnerability. The application of this framework to the mesoscale Mulde catchment in Germany shows that flood risk can vary dramatically as a consequence of plausible change scenarios. It further reveals that components that have not received much attention, such as changes in dike systems or in vulnerability, may outweigh changes in often investigated components, such as climate. Although the specific results are conditional on the case study area and the selected assumptions, they emphasize the need for a broader consideration of potential drivers of change in a comprehensive way. Hence, our approach contributes to a better understanding of how the different risk components influence the overall flood risk.
Y1 - 2018
U6 - https://doi.org/10.5194/nhess-18-3089-2018
SN - 1561-8633
SN - 1684-9981
VL - 18
IS - 11
SP - 3089
EP - 3108
PB - Copernicus
CY - Göttingen
ER -
TY - JOUR
A1 - Speckhann, Gustavo Andrei
A1 - Kreibich, Heidi
A1 - Merz, Bruno
T1 - Inventory of dams in Germany
JF - Earth system science data : the data publishing journal
N2 - Dams are an important element of water resources management. Data about dams are crucial for practitioners, scientists, and policymakers for various purposes, such as seasonal forecasting of water availability or flood mitigation. However, detailed information on dams on the national level for Germany is so far not freely available. We present the most comprehensive open-access dam inventory for Germany (DIG) to date. We have collected and combined information on dams using books, state agency reports, engineering reports, and internet pages. We have applied a priority rule that ensures the highest level of reliability for the dam information. Our dam inventory comprises 530 dams in Germany with information on name, location, river, start year of construction and operation, crest length, dam height, lake area, lake volume, purpose, dam structure, and building characteristics. We have used a global, satellite-based water surface raster to evaluate the location of the dams. A significant proportion (63 %) of dams were built between 1950-2013. Our inventory shows that dams in Germany are mostly single-purpose (52 %), 53% can be used for flood control, and 25% are involved in energy production. The inventory is freely available through GFZ (GeoForschungsZentrum) Data Services (https://doi.org/10.5880/GFZ.4.4.2020.005)
Y1 - 2021
U6 - https://doi.org/10.5194/essd-13-731-2021
SN - 1866-3508
SN - 1866-3516
VL - 13
IS - 2
SP - 731
EP - 740
PB - Copernicus
CY - Göttingen
ER -
TY - JOUR
A1 - Trautmann, Tina
A1 - Koirala, Sujan
A1 - Carvalhais, Nuno
A1 - Güntner, Andreas
A1 - Jung, Martin
T1 - The importance of vegetation in understanding terrestrial water storage variations
JF - Hydrology and Earth System Sciences
N2 - So far, various studies have aimed at decomposing the integrated terrestrial water storage variations observed by satellite gravimetry (GRACE, GRACE-FO) with the help of large-scale hydrological models. While the results of the storage decomposition depend on model structure, little attention has been given to the impact of the way that vegetation is represented in these models. Although vegetation structure and activity represent the crucial link between water, carbon, and energy cycles, their representation in large-scale hydrological models remains a major source of uncertainty. At the same time, the increasing availability and quality of Earth-observation-based vegetation data provide valuable information with good prospects for improving model simulations and gaining better insights into the role of vegetation within the global water cycle. In this study, we use observation-based vegetation information such as vegetation indices and rooting depths for spatializing the parameters of a simple global hydrological model to define infiltration, root water uptake, and transpiration processes. The parameters are further constrained by considering observations of terrestrial water storage anomalies (TWS), soil moisture, evapotranspiration (ET) and gridded runoff ( Q) estimates in a multi-criteria calibration approach. We assess the implications of including varying vegetation characteristics on the simulation results, with a particular focus on the partitioning between water storage components. To isolate the effect of vegetation, we compare a model experiment in which vegetation parameters vary in space and time to a baseline experiment in which all parameters are calibrated as static, globally uniform values. Both experiments show good overall performance, but explicitly including varying vegetation data leads to even better performance and more physically plausible parameter values. The largest improvements regarding TWS and ET are seen in supply-limited (semi-arid) regions and in the tropics, whereas Q simulations improve mainly in northern latitudes. While the total fluxes and storages are similar, accounting for vegetation substantially changes the contributions of different soil water storage components to the TWS variations. This suggests an important role of the representation of vegetation in hydrological models for interpreting TWS variations. Our simulations further indicate a major effect of deeper moisture storages and groundwater-soil moisture-vegetation interactions as a key to understanding TWS variations. We highlight the need for further observations to identify the adequate model structure rather than only model parameters for a reasonable representation and interpretation of vegetation-water interactions.
Y1 - 2022
U6 - https://doi.org/10.5194/hess-26-1089-2022
SN - 1027-5606
SN - 1607-7938
VL - 26
IS - 4
SP - 1089
EP - 1109
PB - Copernicus
CY - Göttingen
ER -
TY - JOUR
A1 - Jing, Miao
A1 - Kumar, Rohini
A1 - Heße, Falk
A1 - Thober, Stephan
A1 - Rakovec, Oldrich
A1 - Samaniego, Luis
A1 - Attinger, Sabine
T1 - Assessing the response of groundwater quantity and travel time distribution to 1.5, 2, and 3 °C global warming in a mesoscale central German basin
JF - Hydrology and Earth System Sciences
N2 - Groundwater is the biggest single source of high-quality freshwater worldwide, which is also continuously threatened by the changing climate. In this paper, we investigate the response of the regional groundwater system to climate change under three global warming levels (1.5, 2, and 3 ∘C) in a central German basin (Nägelstedt). This investigation is conducted by deploying an integrated modeling workflow that consists of a mesoscale hydrologic model (mHM) and a fully distributed groundwater model, OpenGeoSys (OGS). mHM is forced with climate simulations of five general circulation models under three representative concentration pathways. The diffuse recharges estimated by mHM are used as boundary forcings to the OGS groundwater model to compute changes in groundwater levels and travel time distributions. Simulation results indicate that groundwater recharges and levels are expected to increase slightly under future climate scenarios. Meanwhile, the mean travel time is expected to decrease compared to the historical average. However, the ensemble simulations do not all agree on the sign of relative change. Changes in mean travel time exhibit a larger variability than those in groundwater levels. The ensemble simulations do not show a systematic relationship between the projected change (in both groundwater levels and travel times) and the warming level, but they indicate an increased variability in projected changes with adjusting the enhanced warming level from 1.5 to 3 ∘C. Correspondingly, it is highly recommended to restrain the trend of global warming.
KW - climate change impacts
KW - hydrological models
KW - coupled surface
KW - water fluxes
KW - catchment
KW - recharge
KW - dynamics
KW - aquifer
KW - flow
KW - parameterization
Y1 - 2020
U6 - https://doi.org/10.5194/hess-24-1511-2020
SN - 1607-7938
SN - 1027-5606
VL - 24
IS - 3
SP - 1511
EP - 1526
PB - Copernicus Publ.
CY - Göttingen
ER -
TY - JOUR
A1 - Jing, Miao
A1 - Hesse, Falk
A1 - Kumar, Rohini
A1 - Kolditz, Olaf
A1 - Kalbacher, Thomas
A1 - Attinger, Sabine
T1 - Influence of input and parameter uncertainty on the prediction of catchment-scale groundwater travel time distributions
JF - Hydrology and earth system sciences : HESS
N2 - Groundwater travel time distributions (TTDs) provide a robust description of the subsurface mixing behavior and hydrological response of a subsurface system. Lagrangian particle tracking is often used to derive the groundwater TTDs. The reliability of this approach is subjected to the uncertainty of external forcings, internal hydraulic properties, and the interplay between them. Here, we evaluate the uncertainty of catchment groundwater TTDs in an agricultural catchment using a 3-D groundwater model with an overall focus on revealing the relationship between external forcing, internal hydraulic properties, and TTD predictions. Eight recharge realizations are sampled from a high-resolution dataset of land surface fluxes and states. Calibration-constrained hydraulic conductivity fields (Ks fields) are stochastically generated using the null-space Monte Carlo (NSMC) method for each recharge realization. The random walk particle tracking (RWPT) method is used to track the pathways of particles and compute travel times. Moreover, an analytical model under the random sampling (RS) assumption is fit against the numerical solutions, serving as a reference for the mixing behavior of the model domain. The StorAge Selection (SAS) function is used to interpret the results in terms of quantifying the systematic preference for discharging young/old water. The simulation results reveal the primary effect of recharge on the predicted mean travel time (MTT). The different realizations of calibration-constrained Ks fields moderately magnify or attenuate the predicted MTTs. The analytical model does not properly replicate the numerical solution, and it underestimates the mean travel time. Simulated SAS functions indicate an overall preference for young water for all realizations. The spatial pattern of recharge controls the shape and breadth of simulated TTDs and SAS functions by changing the spatial distribution of particles' pathways. In conclusion, overlooking the spatial nonuniformity and uncertainty of input (forcing) will result in biased travel time predictions. We also highlight the worth of reliable observations in reducing predictive uncertainty and the good interpretability of SAS functions in terms of understanding catchment transport processes.
Y1 - 2019
U6 - https://doi.org/10.5194/hess-23-171-2019
SN - 1027-5606
SN - 1607-7938
VL - 23
IS - 1
SP - 171
EP - 190
PB - Copernicus
CY - Göttingen
ER -
TY - JOUR
A1 - Schmidt, Lennart
A1 - Heße, Falk
A1 - Attinger, Sabine
A1 - Kumar, Rohini
T1 - Challenges in applying machine learning models for hydrological inference: a case study for flooding events across Germany
JF - Water Resources Research
N2 - Machine learning (ML) algorithms are being increasingly used in Earth and Environmental modeling studies owing to the ever-increasing availability of diverse data sets and computational resources as well as advancement in ML algorithms. Despite advances in their predictive accuracy, the usefulness of ML algorithms for inference remains elusive. In this study, we employ two popular ML algorithms, artificial neural networks and random forest, to analyze a large data set of flood events across Germany with the goals to analyze their predictive accuracy and their usability to provide insights to hydrologic system functioning. The results of the ML algorithms are contrasted against a parametric approach based on multiple linear regression. For analysis, we employ a model-agnostic framework named Permuted Feature Importance to derive the influence of models' predictors. This allows us to compare the results of different algorithms for the first time in the context of hydrology. Our main findings are that (1) the ML models achieve higher prediction accuracy than linear regression, (2) the results reflect basic hydrological principles, but (3) further inference is hindered by the heterogeneity of results across algorithms. Thus, we conclude that the problem of equifinality as known from classical hydrological modeling also exists for ML and severely hampers its potential for inference. To account for the observed problems, we propose that when employing ML for inference, this should be made by using multiple algorithms and multiple methods, of which the latter should be embedded in a cross-validation routine.
KW - machine learning
KW - inference
KW - floods
Y1 - 2019
VL - 56
IS - 5
PB - John Wiley & Sons, Inc.
CY - New Jersey
ER -
TY - JOUR
A1 - Rottler, Erwin
A1 - Bronstert, Axel
A1 - Bürger, Gerd
A1 - Rakovec, Oldrich
T1 - Projected changes in Rhine River flood seasonality under global warming
JF - Hydrology and earth system sciences : HESS / European Geosciences Union
N2 - Climatic change alters the frequency and intensity of natural hazards. In order to assess potential future changes in flood seasonality in the Rhine River Basin, we analyse changes in streamflow, snowmelt, precipitation, and evapotranspiration at 1.5, 2.0 and 3.0 ◦C global warming levels. The mesoscale Hydrological Model (mHM) forced with an ensemble of climate projection scenarios (five general circulation models under three representative concentration pathways) is used to simulate the present and future climate conditions of both, pluvial and nival hydrological regimes. Our results indicate that the interplay between changes in snowmelt- and rainfall-driven runoff is crucial to understand changes in streamflow maxima in the Rhine River. Climate projections suggest that future changes in flood characteristics in the entire Rhine River are controlled by both, more intense precipitation events and diminishing snow packs. The nature of this interplay defines the type of change in runoff peaks. On the sub-basin level (the Moselle River), more intense rainfall during winter is mostly counterbalanced by reduced snowmelt contribution to the streamflow. In the High Rhine (gauge at Basel), the strongest increases in streamflow maxima show up during winter, when strong increases in liquid precipitation intensity encounter almost unchanged snowmelt-driven runoff. The analysis of snowmelt events suggests that at no point in time during the snowmelt season, a warming climate results in an increase in the risk of snowmelt-driven flooding. We do not find indications of a transient merging of pluvial and nival floods due to climate warming.
Y1 - 2020
U6 - https://doi.org/10.5194/hess-25-2353-2021
SN - 1607-7938
SN - 1027-5606
VL - 25
IS - 5
SP - 2353
EP - 2371
PB - Copernicus Publications
CY - Göttingen
ER -
TY - JOUR
A1 - Bilbao-Lasa, Peru
A1 - Jara Muñoz, Julius
A1 - Pedoja, Kevin
A1 - Álvarez, Irantzu
A1 - Aranburu, Arantza
A1 - Iriarte, Eneko
A1 - Galparsoro, Ibon
T1 - Submerged marine terraces identification and an approach for numerical modeling the sequence formation in the Bay of Biscay (Northeastern Iberian Peninsula)
JF - Frontiers in Earth Science
N2 - Submerged sequences of marine terraces potentially provide crucial information of past sea-level positions. However, the distribution and characteristics of drowned marine terrace sequences are poorly known at a global scale. Using bathymetric data and novel mapping and modeling techniques, we studied a submerged sequence of marine terraces in the Bay of Biscay with the objective to identify the distribution and morphologies of submerged marine terraces and the timing and conditions that allowed their formation and preservation. To accomplish the objectives a high-resolution bathymetry (5 m) was analyzed using Geographic Information Systems and TerraceM(R). The successive submerged terraces were identified using a Surface Classification Model, which linearly combines the slope and the roughness of the surface to extract fossil sea-cliffs and fossil rocky shore platforms. For that purpose, contour and hillshaded maps were also analyzed. Then, shoreline angles, a geomorphic marker located at the intersection between the fossil sea-cliff and platform, were mapped analyzing swath profiles perpendicular to the isobaths. Most of the submerged strandlines are irregularly preserved throughout the continental shelf. In summary, 12 submerged terraces with their shoreline angles between approximately: -13 m (T1), -30 and -32 m (T2), -34 and 41 m (T3), -44 and -47 m (T4), -49 and 53 m (T5), -55 and 58 m (T6), -59 and 62 m (T7), -65 and 67 m (T8), -68 and 70 m (T9), -74 and -77 m (T10), -83 and -86 m (T11) and -89 and 92 m (T12). Nevertheless, the ones showing the best lateral continuity and preservation in the central part of the shelf are T3, T4, T5, T7, T8, and T10. The age of the terraces has been estimated using a landscape evolution model. To simulate the formation and preservation of submerged terraces three different scenarios: (i) 20-0 ka; (ii) 128-0 ka; and (iii) 128-20 ka, were compared. The best scenario for terrace generation was between 128 and 20 Ka, where T3, T5, and T7 could have been formed.
KW - marine terrace
KW - submerged sequence
KW - digital bathymetric model
KW - TerraceM
KW - numerical modeling
KW - Bay of Biscay
Y1 - 2020
U6 - https://doi.org/10.3389/feart.2020.00047
SN - 2296-6463
VL - 8
IS - 47
SP - 1
EP - 20
PB - Frontiers Media
CY - Lausanne
ER -
TY - JOUR
A1 - Veh, Georg
A1 - Lützow, Natalie
A1 - Kharlamova, Varvara
A1 - Petrakov, Dmitry
A1 - Hugonnet, Romain
A1 - Korup, Oliver
T1 - Trends, breaks, and biases in the frequency of reported glacier lake outburst floods
JF - Earth's future
N2 - Thousands of glacier lakes have been forming behind natural dams in high mountains following glacier retreat since the early 20th century. Some of these lakes abruptly released pulses of water and sediment with disastrous downstream consequences. Yet it remains unclear whether the reported rise of these glacier lake outburst floods (GLOFs) has been fueled by a warming atmosphere and enhanced meltwater production, or simply a growing research effort. Here we estimate trends and biases in GLOF reporting based on the largest global catalog of 1,997 dated glacier-related floods in six major mountain ranges from 1901 to 2017. We find that the positive trend in the number of reported GLOFs has decayed distinctly after a break in the 1970s, coinciding with independently detected trend changes in annual air temperatures and in the annual number of field-based glacier surveys (a proxy of scientific reporting). We observe that GLOF reports and glacier surveys decelerated, while temperature rise accelerated in the past five decades. Enhanced warming alone can thus hardly explain the annual number of reported GLOFs, suggesting that temperature-driven glacier lake formation, growth, and failure are weakly coupled, or that outbursts have been overlooked. Indeed, our analysis emphasizes a distinct geographic and temporal bias in GLOF reporting, and we project that between two to four out of five GLOFs on average might have gone unnoticed in the early to mid-20th century. We recommend that such biases should be considered, or better corrected for, when attributing the frequency of reported GLOFs to atmospheric warming.
KW - glaciers
KW - climate change
KW - hazard
KW - mountains
KW - cryosphere
KW - frequency
Y1 - 2022
U6 - https://doi.org/10.1029/2021EF002426
SN - 2328-4277
VL - 10
IS - 3
PB - American Geophysical Union
CY - Washington
ER -
TY - JOUR
A1 - Metin, Ayse Duha
A1 - Dung, Nguyen Viet
A1 - Schröter, Kai
A1 - Vorogushyn, Sergiy
A1 - Guse, Björn
A1 - Kreibich, Heidi
A1 - Merz, Bruno
T1 - The role of spatial dependence for large-scale flood risk estimation
JF - Natural hazards and earth system sciences
N2 - Flood risk assessments are typically based on scenarios which assume homogeneous return periods of flood peaks throughout the catchment. This assumption is unrealistic for real flood events and may bias risk estimates for specific return periods. We investigate how three assumptions about the spatial dependence affect risk estimates: (i) spatially homogeneous scenarios (complete dependence), (ii) spatially heterogeneous scenarios (modelled dependence) and (iii) spatially heterogeneous but uncorrelated scenarios (complete independence). To this end, the model chain RFM (regional flood model) is applied to the Elbe catchment in Germany, accounting for the spatio-temporal dynamics of all flood generation processes, from the rainfall through catchment and river system processes to damage mechanisms. Different assumptions about the spatial dependence do not influence the expected annual damage (EAD); however, they bias the risk curve, i.e. the cumulative distribution function of damage. The widespread assumption of complete dependence strongly overestimates flood damage of the order of 100% for return periods larger than approximately 200 years. On the other hand, for small and medium floods with return periods smaller than approximately 50 years, damage is underestimated. The overestimation aggravates when risk is estimated for larger areas. This study demonstrates the importance of representing the spatial dependence of flood peaks and damage for risk assessments.
Y1 - 2020
U6 - https://doi.org/10.5194/nhess-20-967-2020
SN - 1561-8633
SN - 1684-9981
VL - 20
IS - 4
SP - 967
EP - 979
PB - European Geosciences Union (EGU) ; Copernicus
CY - Göttingen
ER -
TY - JOUR
A1 - Bryant, Seth
A1 - Davies, Evan
A1 - Sol, David
A1 - Davis, Sandy
T1 - The progression of flood risk in southern Alberta since the 2013 flood
JF - Journal of flood risk management
N2 - After a century of semi-restricted floodplain development, Southern Alberta, Canada, was struck by the devastating 2013 Flood. Aging infrastructure and limited property-level floodproofing likely contributed to the $4-6 billion (CAD) losses. Following this catastrophe, Alberta has seen a revival in flood management, largely focused on structural protections. However, concurrent with the recent structural work was a 100,000+ increase in Calgary's population in the 5 years following the flood, leading to further densification of high-hazard areas. This study implements the novel Stochastic Object-based Flood damage Dynamic Assessment (SOFDA) model framework to quantify the progression of the direct-damage flood risk in a mature urban neighborhood after the 2013 Flood. Five years of remote-sensing data, property assessment records, and inundation simulations following the flood are used to construct the model. Results show that in these 5 years, vulnerability trends (like densification) have increased flood risk by 4%; however, recent structural mitigation projects have reduced overall flood risk by 47% for this case study. These results demonstrate that the flood management revival in Southern Alberta has largely been successful at reducing flood risk; however, the gains are under threat from continued development and densification absent additional floodproofing regulations.
KW - Calgary
KW - depth-damage functions
KW - expected annual damages
KW - flood risk
KW - model
KW - property level protection measures
KW - risk analysis
KW - risk dynamics
Y1 - 2022
U6 - https://doi.org/10.1111/jfr3.12811
SN - 1753-318X
VL - 15
IS - 3
PB - Wiley-Blackwell
CY - Oxford
ER -
TY - JOUR
A1 - Ramachandran, Srikanthan
A1 - Rupakheti, Maheswar
A1 - Lawrence, Mark
T1 - Aerosol-induced atmospheric heating rate decreases over South and East Asia as a result of changing content and composition
JF - Scientific reports
N2 - Aerosol emissions from human activities are extensive and changing rapidly over Asia. Model simulations and satellite observations indicate a dipole pattern in aerosol emissions and loading between South Asia and East Asia, two of the most heavily polluted regions of the world. We examine the previously unexplored diverging trends in the existing dipole pattern of aerosols between East and South Asia using the high quality, two-decade long ground-based time series of observations of aerosol properties from the Aerosol Robotic Network (AERONET), from satellites (Moderate Resolution Imaging Spectroradiometer (MODIS) and Ozone Monitoring Instrument (OMI)), and from model simulations (Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2). The data cover the period since 2001 for Kanpur (South Asia) and Beijing (East Asia), two locations taken as being broadly representative of the respective regions. Since 2010 a dipole in aerosol optical depth (AOD) is maintained, but the trend is reversed-the decrease in AOD over Beijing (East Asia) is rapid since 2010, being 17% less in current decade compared to first decade of twenty-first century, while the AOD over South Asia increased by 12% during the same period. Furthermore, we find that the aerosol composition is also changing over time. The single scattering albedo (SSA), a measure of aerosol's absorption capacity and related to aerosol composition, is slightly higher over Beijing than Kanpur, and has increased from 0.91 in 2002 to 0.93 in 2017 over Beijing and from 0.89 to 0.92 during the same period over Kanpur, confirming that aerosols in this region have on an average become more scattering in nature. These changes have led to a notable decrease in aerosol-induced atmospheric heating rate (HR) over both regions between the two decades, decreasing considerably more over East Asia (- 31%) than over South Asia (- 9%). The annual mean HR is lower now, it is still large (>= 0.6 K per day), which has significant climate implications. The seasonal trends in AOD, SSA and HR are more pronounced than their respective annual trends over both regions. The seasonal trends are caused mainly by the increase/decrease in anthropogenic aerosol emissions (sulfate, black carbon and organic carbon) while the natural aerosols (dust and sea salt) did not change significantly over South and East Asia during the last two decades. The MERRA-2 model is able to simulate the observed trends in AODs well but not the magnitude, while it also did not simulate the SSA values or trends well. These robust findings based on observations of key aerosol parameters and previously unrecognized diverging trends over South and East Asia need to be accounted for in current state-of-the-art climate models to ensure accurate quantification of the complex and evolving impact of aerosols on the regional climate over Asia.
Y1 - 2020
U6 - https://doi.org/10.1038/s41598-020-76936-z
SN - 2045-2322
VL - 10
IS - 1
PB - Macmillan Publishers Limited, part of Springer Nature
CY - [London]
ER -
TY - JOUR
A1 - Rözer, Viktor
A1 - Kreibich, Heidi
A1 - Schröter, Kai
A1 - Müller, Meike
A1 - Sairam, Nivedita
A1 - Doss-Gollin, James
A1 - Lall, Upmanu
A1 - Merz, Bruno
T1 - Probabilistic Models Significantly Reduce Uncertainty in Hurricane Harvey Pluvial Flood Loss Estimates
JF - Earths future
N2 - Pluvial flood risk is mostly excluded in urban flood risk assessment. However, the risk of pluvial flooding is a growing challenge with a projected increase of extreme rainstorms compounding with an ongoing global urbanization. Considered as a flood type with minimal impacts when rainfall rates exceed the capacity of urban drainage systems, the aftermath of rainfall-triggered flooding during Hurricane Harvey and other events show the urgent need to assess the risk of pluvial flooding. Due to the local extent and small-scale variations, the quantification of pluvial flood risk requires risk assessments on high spatial resolutions. While flood hazard and exposure information is becoming increasingly accurate, the estimation of losses is still a poorly understood component of pluvial flood risk quantification. We use a new probabilistic multivariable modeling approach to estimate pluvial flood losses of individual buildings, explicitly accounting for the associated uncertainties. Except for the water depth as the common most important predictor, we identified the drivers for having loss or not and for the degree of loss to be different. Applying this approach to estimate and validate building structure losses during Hurricane Harvey using a property level data set, we find that the reliability and dispersion of predictive loss distributions vary widely depending on the model and aggregation level of property level loss estimates. Our results show that the use of multivariable zero-inflated beta models reduce the 90% prediction intervalsfor Hurricane Harvey building structure loss estimates on average by 78% (totalling U.S.$3.8 billion) compared to commonly used models.
KW - pluvial flooding
KW - loss modeling
KW - urban flooding
KW - probabilistic
KW - Hurricane Harvey
KW - climate change adaptation
Y1 - 2019
U6 - https://doi.org/10.1029/2018EF001074
SN - 2328-4277
VL - 7
IS - 4
SP - 384
EP - 394
PB - American Geophysical Union
CY - Washington
ER -
TY - JOUR
A1 - Sairam, Nivedita
A1 - Schröter, Kai
A1 - Lüdtke, Stefan
A1 - Merz, Bruno
A1 - Kreibich, Heidi
T1 - Quantifying Flood Vulnerability Reduction via Private Precaution
JF - Earth future
N2 - Private precaution is an important component in contemporary flood risk management and climate adaptation. However, quantitative knowledge about vulnerability reduction via private precautionary measures is scarce and their effects are hardly considered in loss modeling and risk assessments. However, this is a prerequisite to enable temporally dynamic flood damage and risk modeling, and thus the evaluation of risk management and adaptation strategies. To quantify the average reduction in vulnerability of residential buildings via private precaution empirical vulnerability data (n = 948) is used. Households with and without precautionary measures undertaken before the flood event are classified into treatment and nontreatment groups and matched. Postmatching regression is used to quantify the treatment effect. Additionally, we test state-of-the-art flood loss models regarding their capability to capture this difference in vulnerability. The estimated average treatment effect of implementing private precaution is between 11 and 15 thousand EUR per household, confirming the significant effectiveness of private precautionary measures in reducing flood vulnerability. From all tested flood loss models, the expert Bayesian network-based model BN-FLEMOps and the rule-based loss model FLEMOps perform best in capturing the difference in vulnerability due to private precaution. Thus, the use of such loss models is suggested for flood risk assessments to effectively support evaluations and decision making for adaptable flood risk management.
KW - flood loss
KW - average treatment effect
KW - matching methods
KW - loss models
KW - risk analysis
KW - adaptation
Y1 - 2019
U6 - https://doi.org/10.1029/2018EF000994
SN - 2328-4277
VL - 7
IS - 3
SP - 235
EP - 249
PB - American Geophysical Union
CY - Washington
ER -
TY - JOUR
A1 - Dietze, Michael
A1 - Bell, Rainer
A1 - Öztürk, Ugur
A1 - Cook, Kristen L.
A1 - Andermann, Christoff
A1 - Beer, Alexander R.
A1 - Damm, Bodo
A1 - Lucia, Ana
A1 - Fauer, Felix S.
A1 - Nissen, Katrin M.
A1 - Sieg, Tobias
A1 - Thieken, Annegret H.
T1 - More than heavy rain turning into fast-flowing water - a landscape perspective on the 2021 Eifel floods
JF - Natural hazards and earth system sciences
N2 - Rapidly evolving floods are rare but powerful drivers of landscape reorganisation that have severe and long-lasting impacts on both the functions of a landscape's subsystems and the affected society. The July 2021 flood that particularly hit several river catchments of the Eifel region in western Germany and Belgium was a drastic example. While media and scientists highlighted the meteorological and hydrological aspects of this flood, it was not just the rising water levels in the main valleys that posed a hazard, caused damage, and drove environmental reorganisation. Instead, the concurrent coupling of landscape elements and the wood, sediment, and debris carried by the fast-flowing water made this flood so devastating and difficult to predict. Because more intense floods are able to interact with more landscape components, they at times reveal rare non-linear feedbacks, which may be hidden during smaller events due to their high thresholds of initiation. Here, we briefly review the boundary conditions of the 14-15 July 2021 flood and discuss the emerging features that made this event different from previous floods. We identify hillslope processes, aspects of debris mobilisation, the legacy of sustained human land use, and emerging process connections and feedbacks as critical non-hydrological dimensions of the flood. With this landscape scale perspective, we develop requirements for improved future event anticipation, mitigation, and fundamental system understanding.
Y1 - 2022
U6 - https://doi.org/10.5194/nhess-22-1845-2022
SN - 1561-8633
SN - 1684-9981
VL - 22
IS - 6
SP - 1845
EP - 1856
PB - Copernicus
CY - Göttingen
ER -
TY - JOUR
A1 - Herzschuh, Ulrike
A1 - Cao, Xianyong
A1 - Laepple, Thomas
A1 - Dallmeyer, Anne
A1 - Telford, Richard J.
A1 - Ni, Jian
A1 - Chen, Fahu
A1 - Kong, Zhaochen
A1 - Liu, Guangxiu
A1 - Liu, Kam-Biu
A1 - Liu, Xingqi
A1 - Stebich, Martina
A1 - Tang, Lingyu
A1 - Tian, Fang
A1 - Wang, Yongbo
A1 - Wischnewski, Juliane
A1 - Xu, Qinghai
A1 - Yan, Shun
A1 - Yang, Zhenjing
A1 - Yu, Ge
A1 - Zhang, Yun
A1 - Zhao, Yan
A1 - Zheng, Zhuo
T1 - Position and orientation of the westerly jet determined Holocene rainfall patterns in China
JF - Nature Communications
N2 - Proxy-based reconstructions and modeling of Holocene spatiotemporal precipitation patterns for China and Mongolia have hitherto yielded contradictory results indicating that the basic mechanisms behind the East Asian Summer Monsoon and its interaction with the westerly jet stream remain poorly understood. We present quantitative reconstructions of Holocene precipitation derived from 101 fossil pollen records and analyse them with the help of a minimal empirical model. We show that the westerly jet-stream axis shifted gradually southward and became less tilted since the middle Holocene. This was tracked by the summer monsoon rain band resulting in an early-Holocene precipitation maximum over most of western China, a mid-Holocene maximum in north-central and northeastern China, and a late-Holocene maximum in southeastern China. Our results suggest that a correct simulation of the orientation and position of the westerly jet stream is crucial to the reliable prediction of precipitation patterns in China and Mongolia.
Y1 - 2019
U6 - https://doi.org/10.1038/s41467-019-09866-8
SN - 2041-1723
VL - 10
PB - Nature Publ. Group
CY - London
ER -
TY - JOUR
A1 - Steirou, Eva
A1 - Gerlitz, Lars
A1 - Apel, Heiko
A1 - Sun, Xun
A1 - Merz, Bruno
T1 - Climate influences on flood probabilities across Europe
JF - Hydrology and earth system sciences : HESS
N2 - The link between streamflow extremes and climatology has been widely studied in recent decades. However, a study investigating the effect of large-scale circulation variations on the distribution of seasonal discharge extremes at the European level is missing. Here we fit a climate-informed generalized extreme value (GEV) distribution to about 600 streamflow records in Europe for each of the standard seasons, i.e., to winter, spring, summer and autumn maxima, and compare it with the classical GEV distribution with parameters invariant in time. The study adopts a Bayesian framework and covers the period 1950 to 2016. Five indices with proven influence on the European climate are examined independently as covariates, namely the North Atlantic Oscillation (NAO), the east Atlantic pattern (EA), the east Atlantic-western Russian pattern (EA/WR), the Scandinavia pattern (SCA) and the polar-Eurasian pattern (POL). It is found that for a high percentage of stations the climate-informed model is preferred to the classical model. Particularly for NAO during winter, a strong influence on streamflow extremes is detected for large parts of Europe (preferred to the classical GEV distribution for 46% of the stations). Climate-informed fits are characterized by spatial coherence and form patterns that resemble relations between the climate indices and seasonal precipitation, suggesting a prominent role of the considered circulation modes for flood generation. For certain regions, such as northwestern Scandinavia and the British Isles, yearly variations of the mean seasonal climate indices result in considerably different extreme value distributions and thus in highly different flood estimates for individual years that can also persist for longer time periods.
Y1 - 2019
U6 - https://doi.org/10.5194/hess-23-1305-2019
SN - 1027-5606
SN - 1607-7938
VL - 23
IS - 3
SP - 1305
EP - 1322
PB - Copernicus
CY - Göttingen
ER -
TY - JOUR
A1 - Dietze, Elisabeth
A1 - Mangelsdorf, Kai
A1 - Andreev, Andrei
A1 - Karger, Cornelia
A1 - Schreuder, Laura T.
A1 - Hopmans, Ellen C.
A1 - Rach, Oliver
A1 - Sachse, Dirk
A1 - Wennrich, Volker
A1 - Herzschuh, Ulrike
T1 - Relationships between low-temperature fires, climate and vegetation during three late glacials and interglacials of the last 430 kyr in northeastern Siberia reconstructed from monosaccharide anhydrides in Lake El’gygytgyn sediments
JF - Climate of the Past
N2 - Landscapes in high northern latitudes are assumed to be highly sensitive to future global change, but the rates and long-term trajectories of changes are rather uncertain. In the boreal zone, fires are an important factor in climate-vegetation interactions and biogeochemical cycles. Fire regimes are characterized by small, frequent, low-intensity fires within summergreen boreal forests dominated by larch, whereas evergreen boreal forests dominated by spruce and pine burn large areas less frequently but at higher intensities. Here, we explore the potential of the monosaccharide anhydrides (MA) levoglucosan, mannosan and galactosan to serve as proxies of low-intensity biomass burning in glacial-to-interglacial lake sediments from the high northern latitudes. We use sediments from Lake El'gygytgyn (cores PG 1351 and ICDP 5011-1), located in the far north-east of Russia, and study glacial and interglacial samples of the last 430 kyr (marine isotope stages 5e, 6, 7e, 8, 11c and 12) that had different climate and biome configurations. Combined with pollen and non-pollen palynomorph records from the same samples, we assess how far the modern relationships between fire, climate and vegetation persisted during the past, on orbital to centennial timescales. We find that MAs attached to particulates were well-preserved in up to 430 kyr old sediments with higher influxes from low-intensity biomass burning in interglacials compared to glacials. MA influxes significantly increase when summergreen boreal forest spreads closer to the lake, whereas they decrease when tundra-steppe environments and, especially, Sphagnum peatlands spread. This suggests that low-temperature fires are a typical characteristic of Siberian larch forests also on long timescales. The results also suggest that low-intensity fires would be reduced by vegetation shifts towards very dry environments due to reduced biomass availability, as well as by shifts towards peatlands, which limits fuel dryness. In addition, we observed very low MA ratios, which we interpret as high contributions of galactosan and mannosan from biomass sources other than those currently monitored, such as the moss-lichen mats in the understorey of the summergreen boreal forest. Overall, sedimentary MAs can provide a powerful proxy for fire regime reconstructions and extend our knowledge of long-term natural fire-climate-vegetation feedbacks in the high northern latitudes.
KW - molecular tracers
KW - organic aerosols
KW - emission factors
KW - carbonaceous aerosols
KW - pollen records
KW - core PG1351
KW - biomass
KW - holocene
KW - levoglucosan
KW - charcoal
Y1 - 2020
U6 - https://doi.org/10.5194/cp-16-799-2020
SN - 1814-9332
SN - 1814-9324
VL - 16
IS - 2
SP - 788
EP - 818
PB - Copernicus Publications
CY - Göttingen
ER -
TY - JOUR
A1 - Miesner, Timon
A1 - Herzschuh, Ulrike
A1 - Pestryakova, Luidmila Agafyevna
A1 - Wieczorek, Mareike
A1 - Zakharov, Evgenii S.
A1 - Kolmogorov, Alexei I.
A1 - Davydova, Paraskovya V.
A1 - Kruse, Stefan
T1 - Forest structure and individual tree inventories of northeastern Siberia along climatic gradients
JF - Earth system science data : ESSD
N2 - We compile a data set of forest surveys from expeditions to the northeast of the Russian Federation, in Krasnoyarsk Krai, the Republic of Sakha (Yakutia), and the Chukotka Autonomous Okrug (59-73 degrees N, 97-169 degrees E), performed between the years 2011 and 2021. The region is characterized by permafrost soils and forests dominated by larch (Larix gmelinii Rupr. and Larix cajanderi Mayr).
Our data set consists of a plot database describing 226 georeferenced vegetation survey plots and a tree database with information about all the trees on these plots. The tree database, consisting of two tables with the same column names, contains information on the height, species, and vitality of 40 289 trees. A subset of the trees was subject to a more detailed inventory, which recorded the stem diameter at base and at breast height, crown diameter, and height of the beginning of the crown.
We recorded heights up to 28.5 m (median 2.5 m) and stand densities up to 120 000 trees per hectare (median 1197 ha(-1)), with both values tending to be higher in the more southerly areas. Observed taxa include Larix Mill., Pinus L., Picea A. Dietr., Abies Mill., Salix L., Betula L., Populus L., Alnus Mill., and Ulmus L.
In this study, we present the forest inventory data aggregated per plot. Additionally, we connect the data with different remote sensing data products to find out how accurately forest structure can be predicted from such products. Allometries were calculated to obtain the diameter from height measurements for every species group. For Larix, the most frequent of 10 species groups, allometries depended also on the stand density, as denser stands are characterized by thinner trees, relative to height. The remote sensing products used to compare against the inventory data include climate, forest biomass, canopy height, and forest loss or disturbance. We find that the forest metrics measured in the field can only be reconstructed from the remote sensing data to a limited extent, as they depend on local properties. This illustrates the need for ground inventories like those data we present here.
The data can be used for studying the forest structure of northeastern Siberia and for the calibration and validation of remotely sensed data.
Y1 - 2022
U6 - https://doi.org/10.5194/essd-14-5695-2022
SN - 1866-3508
SN - 1866-3516
VL - 14
IS - 12
SP - 5695
EP - 5716
PB - Copernicus
CY - Göttingen
ER -
TY - JOUR
A1 - Kruse, Stefan
A1 - Stünzi, Simone Maria
A1 - Boike, Julia
A1 - Langer, Moritz
A1 - Gloy, Josias
A1 - Herzschuh, Ulrike
T1 - Novel coupled permafrost-forest model (LAVESI-CryoGrid v1.0) revealing the interplay between permafrost, vegetation, and climate across eastern Siberia
JF - Geoscientific model development : GMD ; an interactive open access journal of the European Geosciences Union
N2 - Boreal forests of Siberia play a relevant role in the global carbon cycle. However, global warming threatens the existence of summergreen larch-dominated ecosystems, likely enabling a transition to evergreen tree taxa with deeper active layers. Complex permafrost-vegetation interactions make it uncertain whether these ecosystems could develop into a carbon source rather than continuing atmospheric carbon sequestration under global warming. Consequently, shedding light on the role of current and future active layer dynamics and the feedbacks with the apparent tree species is crucial to predict boreal forest transition dynamics and thus for aboveground forest biomass and carbon stock developments. Hence, we established a coupled model version amalgamating a one-dimensional permafrost multilayer forest land-surface model (CryoGrid) with LAVESI, an individual-based and spatially explicit forest model for larch species (Larix Mill.), extended for this study by including other relevant Siberian forest species and explicit terrain.
Following parameterization, we ran simulations with the coupled version to the near future to 2030 with a mild climate-warming scenario. We focus on three regions covering a gradient of summergreen forests in the east at Spasskaya Pad, mixed summergreen-evergreen forests close to Nyurba, and the warmest area at Lake Khamra in the southeast of Yakutia, Russia. Coupled simulations were run with the newly implemented boreal forest species and compared to runs allowing only one species at a time, as well as to simulations using just LAVESI. Results reveal that the coupled version corrects for overestimation of active layer thickness (ALT) and soil moisture, and large differences in established forests are simulated. We conclude that the coupled version can simulate the complex environment of eastern Siberia by reproducing vegetation patterns, making it an excellent tool to disentangle processes driving boreal forest dynamics.
Y1 - 2022
U6 - https://doi.org/10.5194/gmd-15-2395-2022
SN - 1991-959X
SN - 1991-9603
VL - 15
IS - 6
SP - 2395
EP - 2422
PB - Copernicus
CY - Göttingen
ER -
TY - JOUR
A1 - Radosavljevic, Boris
A1 - Lantuit, Hugues
A1 - Knoblauch, Christian
A1 - Couture, Nicole
A1 - Herzschuh, Ulrike
A1 - Fritz, Michael
T1 - Arctic nearshore sediment dynamics - an example from Herschel Island - Qikiqtaruk, Canada
JF - Journal of marine science and engineering
N2 - Increasing arctic coastal erosion rates imply a greater release of sediments and organic matter into the coastal zone. With 213 sediment samples taken around Herschel Island-Qikiqtaruk, Canadian Beaufort Sea, we aimed to gain new insights on sediment dynamics and geochemical properties of a shallow arctic nearshore zone. Spatial characteristics of nearshore sediment texture (moderately to poorly sorted silt) are dictated by hydrodynamic processes, but ice-related processes also play a role. We determined organic matter (OM) distribution and inferred the origin and quality of organic carbon by C/N ratios and stable carbon isotopes delta C-13. The carbon content was higher offshore and in sheltered areas (mean: 1.0 wt.%., S.D.: 0.9) and the C/N ratios also showed a similar spatial pattern (mean: 11.1, S.D.: 3.1), while the delta C-13 (mean: -26.4 parts per thousand VPDB, S.D.: 0.4) distribution was more complex. We compared the geochemical parameters of our study with terrestrial and marine samples from other studies using a bootstrap approach. Sediments of the current study contained 6.5 times and 1.8 times less total organic carbon than undisturbed and disturbed terrestrial sediments, respectively. Therefore, degradation of OM and separation of carbon pools take place on land and continue in the nearshore zone, where OM is leached, mineralized, or transported beyond the study area.
KW - permafrost
KW - Arctic Ocean
KW - stable carbon isotopes
KW - nitrogen
KW - sediment
KW - chemistry
KW - sediment dynamics
KW - Beaufort Sea
KW - grain size
Y1 - 2022
U6 - https://doi.org/10.3390/jmse10111589
SN - 2077-1312
VL - 10
IS - 11
PB - MDPI
CY - Basel
ER -
TY - JOUR
A1 - Dallmeyer, Anne
A1 - Kleinen, Thomas
A1 - Claussen, Martin
A1 - Weitzel, Nils
A1 - Cao, Xianyong
A1 - Herzschuh, Ulrike
T1 - The deglacial forest conundrum
JF - Nature Communications
N2 - How fast the Northern Hemisphere (NH) forest biome tracks strongly warming climates is largely unknown. Regional studies reveal lags between decades and millennia. Here we report a conundrum: Deglacial forest expansion in the NH extra-tropics occurs approximately 4000 years earlier in a transient MPI-ESM1.2 simulation than shown by pollen-based biome reconstructions. Shortcomings in the model and the reconstructions could both contribute to this mismatch, leaving the underlying causes unresolved. The simulated vegetation responds within decades to simulated climate changes, which agree with pollen-independent reconstructions. Thus, we can exclude climate biases as main driver for differences. Instead, the mismatch points at a multi-millennial disequilibrium of the NH forest biome to the climate signal. Therefore, the evaluation of time-slice simulations in strongly changing climates with pollen records should be critically reassessed. Our results imply that NH forests may be responding much slower to ongoing climate changes than Earth System Models predict.
Deglacial forest expansion in the Northern Hemisphere poses a conundrum: Model results agree with the climate signal but are several millennia ahead of reconstructed forest dynamics. The underlying causes remain unsolved.
Y1 - 2022
U6 - https://doi.org/10.1038/s41467-022-33646-6
SN - 2041-1723
VL - 13
IS - 1
PB - Nature Publishing Group UK
CY - [London]
ER -
TY - JOUR
A1 - Kruse, Stefan
A1 - Herzschuh, Ulrike
T1 - Regional opportunities for tundra conservation in the next 1000 years
JF - eLife
N2 - The biodiversity of tundra areas in northern high latitudes is threatened by invasion of forests under global warming. However, poorly understood nonlinear responses of the treeline ecotone mean the timing and extent of tundra losses are unclear, but policymakers need such information to optimize conservation efforts. Our individual-based model LAVESI, developed for the Siberian tundra-taiga ecotone, can help improve our understanding. Consequently, we simulated treeline migration trajectories until the end of the millennium, causing a loss of tundra area when advancing north. Our simulations reveal that the treeline follows climate warming with a severe, century-long time lag, which is overcompensated by infilling of stands in the long run even when temperatures cool again. Our simulations reveal that only under ambitious mitigation strategies (relative concentration pathway 2.6) will ~30% of original tundra areas remain in the north but separated into two disjunct refugia.
KW - Larix gmelinii
KW - Larix cajanderi
KW - nonlinear response
KW - treeline ecotone
KW - tundra
KW - Ecology
KW - Short Report
Y1 - 2022
U6 - https://doi.org/10.7554/eLife.75163
SN - 2050-084X
VL - 11
PB - eLife Sciences Publications
CY - Cambridge
ER -
TY - JOUR
A1 - Li, Chenzhi
A1 - Postl, Alexander K.
A1 - Böhmer, Thomas
A1 - Cao, Xianyong
A1 - Dolman, Andrew M.
A1 - Herzschuh, Ulrike
T1 - Harmonized chronologies of a global late Quaternary pollen dataset (LegacyAge 1.0)
JF - Earth system science data : ESSD
N2 - We present a chronology framework named LegacyAge 1.0 containing harmonized chronologies for 2831 pollen records (downloaded from the Neotoma Paleoecology Database and the supplementary Asian datasets) together with their age control points and metadata in machine-readable data formats.
All chronologies use the Bayesian framework implemented in Bacon version 2.5.3. Optimal parameter settings of priors (accumulation.shape, memory.strength, memory.mean, accumulation.rate, and thickness) were identified based on information in the original publication or iteratively after preliminary model inspection.
The most common control points for the chronologies are radiocarbon dates (86.1 %), calibrated by the latest calibration curves (IntCal20 and SHCal20 for the terrestrial radiocarbon dates in the Northern Hemisphere and Southern Hemisphere and Marine20 for marine materials).
The original publications were consulted when dealing with outliers and inconsistencies. Several major challenges when setting up the chronologies included the waterline issue (18.8% of records), reservoir effect (4.9 %), and sediment deposition discontinuity (4.4 %).
Finally, we numerically compare the LegacyAge 1.0 chronologies to those published in the original publications and show that the reliability of the chronologies of 95.4% of records could be improved according to our assessment.
Our chronology framework and revised chronologies provide the opportunity to make use of the ages and age uncertainties in synthesis studies of, for example, pollen-based vegetation and climate change.
The LegacyAge 1.0 dataset, including metadata, datings, harmonized chronologies, and R code used, is openaccess and available at PANGAEA (https://doi.org/10.1594/PANGAEA.933132; Li et al., 2021) and Zenodo (https://doi.org/10.5281/zenodo.5815192; Li et al., 2022), respectively.
Y1 - 2022
U6 - https://doi.org/10.5194/essd-14-1331-2022
SN - 1866-3508
SN - 1866-3516
VL - 14
IS - 3
SP - 1331
EP - 1343
PB - Copernics Publications
CY - Katlenburg-Lindau
ER -
TY - JOUR
A1 - Courtin, Jérémy
A1 - Andreev, Andrei
A1 - Raschke, Elena
A1 - Bala, Sarah
A1 - Biskaborn, Boris
A1 - Liu, Sisi
A1 - Zimmermann, Heike
A1 - Diekmann, Bernhard
A1 - Stoof-Leichsenring, Kathleen R.
A1 - Pestryakova, Luidmila Agafyevna
A1 - Herzschuh, Ulrike
T1 - Vegetation changes in Southeastern Siberia during the late pleistocene and the holocene
JF - Frontiers in Ecology and Evolution
N2 - Relationships between climate, species composition, and species richness are of particular importance for understanding how boreal ecosystems will respond to ongoing climate change. This study aims to reconstruct changes in terrestrial vegetation composition and taxa richness during the glacial Late Pleistocene and the interglacial Holocene in the sparsely studied southeastern Yakutia (Siberia) by using pollen and sedimentary ancient DNA (sedaDNA) records. Pollen and sedaDNA metabarcoding data using the trnL g and h markers were obtained from a sediment core from Lake Bolshoe Toko. Both proxies were used to reconstruct the vegetation composition, while metabarcoding data were also used to investigate changes in plant taxa richness. The combination of pollen and sedaDNA approaches allows a robust estimation of regional and local past terrestrial vegetation composition around Bolshoe Toko during the last similar to 35,000 years. Both proxies suggest that during the Late Pleistocene, southeastern Siberia was covered by open steppe-tundra dominated by graminoids and forbs with patches of shrubs, confirming that steppe-tundra extended far south in Siberia. Both proxies show disturbance at the transition between the Late Pleistocene and the Holocene suggesting a period with scarce vegetation, changes in the hydrochemical conditions in the lake, and in sedimentation rates. Both proxies document drastic changes in vegetation composition in the early Holocene with an increased number of trees and shrubs and the appearance of new tree taxa in the lake's vicinity. The sedaDNA method suggests that the Late Pleistocene steppe-tundra vegetation supported a higher number of terrestrial plant taxa than the forested Holocene. This could be explained, for example, by the "keystone herbivore" hypothesis, which suggests that Late Pleistocene megaherbivores were able to maintain a high plant diversity. This is discussed in the light of the data with the broadly accepted species-area hypothesis as steppe-tundra covered such an extensive area during the Late Pleistocene.
KW - last glacial
KW - Holocene
KW - Lake Bolshoe Toko
KW - paleoenvironments
KW - sedimentary ancient DNA
KW - metabarcoding
KW - trnL
KW - pollen
Y1 - 2021
U6 - https://doi.org/10.3389/fevo.2021.625096
SN - 2296-701X
VL - 9
PB - Frontiers Media
CY - Lausanne
ER -
TY - JOUR
A1 - Glückler, Ramesh
A1 - Herzschuh, Ulrike
A1 - Kruse, Stefan
A1 - Andreev, Andrei
A1 - Vyse, Stuart Andrew
A1 - Winkler, Bettina
A1 - Biskaborn, Boris
A1 - Pestryakova, Luidmila Agafyevna
A1 - Dietze, Elisabeth
T1 - Wildfire history of the boreal forest of south-western Yakutia (Siberia) over the last two millennia documented by a lake-sediment charcoal record
JF - Biogeosciences : BG / European Geosciences Union
N2 - Wildfires, as a key disturbance in forest ecosystems, are shaping the world's boreal landscapes. Changes in fire regimes are closely linked to a wide array of environmental factors, such as vegetation composition, climate change, and human activity. Arctic and boreal regions and, in particular, Siberian boreal forests are experiencing rising air and ground temperatures with the subsequent degradation of permafrost soils leading to shifts in tree cover and species composition. Compared to the boreal zones of North America or Europe, little is known about how such environmental changes might influence long-term fire regimes in Russia. The larch-dominated eastern Siberian deciduous boreal forests differ markedly from the composition of other boreal forests, yet data about past fire regimes remain sparse. Here, we present a high-resolution macroscopic charcoal record from lacustrine sediments of Lake Khamra (southwest Yakutia, Siberia) spanning the last ca. 2200 years, including information about charcoal particle sizes and morphotypes. Our results reveal a phase of increased charcoal accumulation between 600 and 900 CE, indicative of relatively high amounts of burnt biomass and high fire frequencies. This is followed by an almost 900-year-long period of low charcoal accumulation without significant peaks likely corresponding to cooler climate conditions. After 1750 CE fire frequencies and the relative amount of biomass burnt start to increase again, coinciding with a warming climate and increased anthropogenic land development after Russian colonization. In the 20th century, total charcoal accumulation decreases again to very low levels despite higher fire frequency, potentially reflecting a change in fire management strategies and/or a shift of the fire regime towards more frequent but smaller fires. A similar pattern for different charcoal morphotypes and comparison to a pollen and non-pollen palynomorph (NPP) record from the same sediment core indicate that broad-scale changes in vegetation composition were probably not a major driver of recorded fire regime changes. Instead, the fire regime of the last two millennia at Lake Khamra seems to be controlled mainly by a combination of short-term climate variability and anthropogenic fire ignition and suppression.
Y1 - 2021
U6 - https://doi.org/10.5194/bg-18-4185-2021
SN - 1726-4170
SN - 1726-4189
VL - 18
IS - 13
SP - 4185
EP - 4209
PB - Copernicus
CY - Göttingen
ER -
TY - JOUR
A1 - Liu, Sisi
A1 - Stoof-Leichsenring, Kathleen Rosemarie
A1 - Kruse, Stefan
A1 - Pestryakova, Luidmila Agafyevna
A1 - Herzschuh, Ulrike
T1 - Holocene vegetation and plant diversity changes in the north-eastern Siberian treeline region from pollen and sedimentary ancient DNA
JF - Frontiers in Ecology and Evolution
N2 - Although sedimentary ancient DNA (sedaDNA) has been increasingly used to study paleoecological dynamics (Schulte et al., 2020), the approach has rarely been compared with the traditional method of pollen analysis for investigating past changes in the vegetation composition and diversity of Arctic treeline areas. Here, we provide a history of latitudinal floristic composition and species diversity based on a comparison ofsedaDNA and pollen data archived in three Siberian lake sediment cores spanning the mid-Holocene to the present (7.6-0 cal ka BP), from northern typical tundra to southern open larch forest in the Omoloy region. Our results show that thesedaDNA approach identifies more plant taxa found in the local vegetation communities, while the corresponding pollen analysis mainly captures the regional vegetation development and has its limitations for plant diversity reconstruction. Measures of alpha diversity were calculated based onsedaDNA data recovered from along a tundra to forest tundra to open larch forest gradient. Across all sites,sedaDNA archives provide a complementary record of the vegetation transition within each lake's catchment, tracking a distinct latitudinal vegetation type range from larch tree/alder shrub (open larch forest site) to dwarf shrub-steppe (forest tundra) to wet sedge tundra (typical tundra site). By contrast, the pollen data reveal an open landscape, which cannot distinguish the temporal changes in compositional vegetation for the open larch forest site and forest-tundra site. IncreasingLarixpollen percentages were recorded in the forest-tundra site in the last millenium although noLarixDNA was detected, suggesting that thesedaDNA approach performs better for tracking the local establishment ofLarix. Highest species richness and diversity are found in the mid-Holocene (before 4.4 ka) at the typical tundra site with a diverse range of vegetational habitats, while lowest species richness is recorded for the forest tundra where dwarf-willow habitats dominated the lake's catchment. During the late Holocene, strong declines in species richness and diversity are found at the typical tundra site with the vegetation changing to relatively simple communities. Nevertheless, plant species richness is mostly higher than at the forest-tundra site, which shows a slightly decreasing trend. Plant species richness at the open larch forest site fluctuates through time and is higher than the other sites since around 2.5 ka. Taken together, there is no evidence to suggest that the latitudinal gradients in species diversity changes are present at a millennial scale. Additionally, a weak correlation between the principal component analysis (PCA) site scores ofsedaDNA and species richness suggests that climate may not be a direct driver of species turnover within a lake's catchment. Our data suggest thatsedaDNA and pollen have different but complementary abilities for reconstructing past vegetation and species diversity along a latitude.
KW - sedimentary ancient DNA
KW - metabarcoding
KW - pollen
KW - Siberia
KW - palaeovegetation
KW - plant diversity
KW - latitudinal gradient
Y1 - 2020
U6 - https://doi.org/10.3389/fevo.2020.560243
SN - 2296-701X
VL - 8
PB - Frontiers Media
CY - Lausanne
ER -
TY - JOUR
A1 - Cao, Xianyong
A1 - Tian, Fang
A1 - Andreev, Andrei
A1 - Anderson, Patricia M.
A1 - Lozhkin, Anatoly V.
A1 - Bezrukova, Elena
A1 - Ni, Jian
A1 - Rudaya, Natalia
A1 - Stobbe, Astrid
A1 - Wieczorek, Mareike
A1 - Herzschuh, Ulrike
T1 - A taxonomically harmonized and temporally standardized fossil pollen dataset from Siberia covering the last 40 kyr
JF - Earth System Science Data
N2 - Pollen records from Siberia are mostly absent in global or Northern Hemisphere synthesis works. Here we present a taxonomically harmonized and temporally standardized pollen dataset that was synthesized using 173 palynological records from Siberia and adjacent areas (northeastern Asia, 42-75 degrees N, 50-180 degrees E). Pollen data were taxonomically harmonized, i.e. the original 437 taxa were assigned to 106 combined pollen taxa. Age-depth models for all records were revised by applying a constant Bayesian age-depth modelling routine. The pollen dataset is available as count data and percentage data in a table format (taxa vs. samples), with age information for each sample. The dataset has relatively few sites covering the last glacial period between 40 and 11.5 ka (calibrated thousands of years before 1950 CE) particularly from the central and western part of the study area. In the Holocene period, the dataset has many sites from most of the area, with the exception of the central part of Siberia. Of the 173 pollen records, 81 % of pollen counts were downloaded from open databases (GPD, EPD, PANGAEA) and 10 % were contributions by the original data gatherers, while a few were digitized from publications. Most of the pollen records originate from peatlands (48 %) and lake sediments (33 %). Most of the records (83 %) have >= 3 dates, allowing the establishment of reliable chronologies. The dataset can be used for various purposes, including pollen data mapping (example maps for Larix at selected time slices are shown) as well as quantitative climate and vegetation reconstructions. The datasets for pollen counts and pollen percentages are available at https://doi.org/10.1594/PANGAEA.898616 (Cao et al., 2019a), also including the site information, data source, original publication, dating data, and the plant functional type for each pollen taxa.
KW - Late Quaternary vegetation
KW - Holocene environmental history
KW - eastern continental Asia
KW - plant macrofossil data
KW - late pleistocene
KW - paleoenvironmental records
KW - Verkhoyansk mountains
KW - climate dynamics
KW - glacial maximum
KW - Northern Asia
Y1 - 2020
U6 - https://doi.org/10.5194/essd-12-119-2020
SN - 1866-3508
SN - 1866-3516
VL - 12
IS - 1
SP - 119
EP - 135
PB - Copernics Publications
CY - Katlenburg-Lindau
ER -
TY - JOUR
A1 - Schmidt, Lena Katharina
A1 - Francke, Till
A1 - Rottler, Erwin
A1 - Blume, Theresa
A1 - Schöber, Johannes
A1 - Bronstert, Axel
T1 - Suspended sediment and discharge dynamics in a glaciated alpine environment
BT - identifying crucial areas and time periods on several spatial and temporal scales in the Ötztal, Austria
JF - Earth surface dynamics
N2 - Glaciated high-alpine areas are fundamentally altered by climate change, with well-known implications for hydrology, e.g., due to glacier retreat, longer snow-free periods, and more frequent and intense summer rainstorms. While knowledge on how these hydrological changes will propagate to suspended sediment dynamics is still scarce, it is needed to inform mitigation and adaptation strategies. To understand the processes and source areas most relevant to sediment dynamics, we analyzed discharge and sediment dynamics in high temporal resolution as well as their patterns on several spatial scales, which to date few studies have done.
We used a nested catchment setup in the Upper Ötztal in Tyrol, Austria, where high-resolution (15 min) time series of discharge and suspended sediment concentrations are available for up to 15 years (2006–2020). The catchments of the gauges in Vent, Sölden and Tumpen range from 100 to almost 800 km2 with 10 % to 30 % glacier cover and span an elevation range of 930 to 3772 m a.s.l. We analyzed discharge and suspended sediment yields (SSY), their distribution in space, their seasonality and spatial differences therein, and the relative importance of short-term events. We complemented our analysis by linking the observations to satellite-based snow cover maps, glacier inventories, mass balances and precipitation data.
Our results indicate that the areas above 2500 m a.s.l., characterized by glacier tongues and the most recently deglaciated areas, are crucial for sediment generation in all sub-catchments. This notion is supported by the synchronous spring onset of sediment export at the three gauges, which coincides with snowmelt above 2500 m but lags behind spring discharge onsets. This points at a limitation of suspended sediment supply as long as the areas above 2500 m are snow-covered. The positive correlation of annual SSY with glacier cover (among catchments) and glacier mass balances (within a catchment) further supports the importance of the glacier-dominated areas. The analysis of short-term events showed that summer precipitation events were associated with peak sediment concentrations and yields but on average accounted for only 21 % of the annual SSY in the headwaters. These results indicate that under current conditions, thermally induced sediment export (through snow and glacier melt) is dominant in the study area.
Our results extend the scientific knowledge on current hydro-sedimentological conditions in glaciated high-alpine areas and provide a baseline for studies on projected future changes in hydro-sedimentological system dynamics.
Y1 - 2022
U6 - https://doi.org/10.5194/esurf-10-653-2022
SN - 2196-632X
SN - 2196-6311
VL - 10
IS - 3
SP - 653
EP - 669
PB - Copernicus Publications
CY - Göttingen
ER -
TY - JOUR
A1 - Heistermann, Maik
A1 - Bogena, Heye
A1 - Francke, Till
A1 - Güntner, Andreas
A1 - Jakobi, Jannis
A1 - Rasche, Daniel
A1 - Schrön, Martin
A1 - Döpper, Veronika
A1 - Fersch, Benjamin
A1 - Groh, Jannis
A1 - Patil, Amol
A1 - Pütz, Thomas
A1 - Reich, Marvin
A1 - Zacharias, Steffen
A1 - Zengerle, Carmen
A1 - Oswald, Sascha
T1 - Soil moisture observation in a forested headwater catchment: Combining a dense cosmic-ray neutron sensor network with roving and hydrogravimetry at the TERENO site Wüstebach
JF - Earth system science data
N2 - Cosmic-ray neutron sensing (CRNS) has become an effective method to measure soil moisture at a horizontal scale of hundreds of metres and a depth of decimetres. Recent studies proposed operating CRNS in a network with overlapping footprints in order to cover root-zone water dynamics at the small catchment scale and, at the same time, to represent spatial heterogeneity. In a joint field campaign from September to November 2020 (JFC-2020), five German research institutions deployed 15 CRNS sensors in the 0.4 km(2) Wustebach catchment (Eifel mountains, Germany). The catchment is dominantly forested (but includes a substantial fraction of open vegetation) and features a topographically distinct catchment boundary. In addition to the dense CRNS coverage, the campaign featured a unique combination of additional instruments and techniques: hydro-gravimetry (to detect water storage dynamics also below the root zone); ground-based and, for the first time, airborne CRNS roving; an extensive wireless soil sensor network, supplemented by manual measurements; and six weighable lysimeters. Together with comprehensive data from the long-term local research infrastructure, the published data set (available at https://doi.org/10.23728/b2share.756ca0485800474e9dc7f5949c63b872; Heistermann et al., 2022) will be a valuable asset in various research contexts: to advance the retrieval of landscape water storage from CRNS, wireless soil sensor networks, or hydrogravimetry; to identify scale-specific combinations of sensors and methods to represent soil moisture variability; to improve the understanding and simulation of land-atmosphere exchange as well as hydrological and hydrogeological processes at the hillslope and the catchment scale; and to support the retrieval of soil water content from airborne and spaceborne remote sensing platforms.
Y1 - 2022
U6 - https://doi.org/10.5194/essd-14-2501-2022
SN - 1866-3508
SN - 1866-3516
VL - 14
IS - 5
SP - 2501
EP - 2519
PB - Copernicus
CY - Göttingen
ER -
TY - JOUR
A1 - Walch, Daniela M. R.
A1 - Singh, Rakesh K.
A1 - Soreide, Janne E.
A1 - Lantuit, Hugues
A1 - Poste, Amanda
T1 - Spatio-temporal variability of suspended particulate matter in a high-arctic estuary (Adventfjorden, Svalbard) using sentinel-2 time-series
JF - Remote sensing
N2 - Arctic coasts, which feature land-ocean transport of freshwater, sediments, and other terrestrial material, are impacted by climate change, including increased temperatures, melting glaciers, changes in precipitation and runoff.
These trends are assumed to affect productivity in fjordic estuaries.
However, the spatial extent and temporal variation of the freshwater-driven darkening of fjords remain unresolved.
The present study illustrates the spatio-temporal variability of suspended particulate matter (SPM) in the Adventfjorden estuary, Svalbard, using in-situ field campaigns and ocean colour remote sensing (OCRS) via high-resolution Sentinel-2 imagery.
To compute SPM concentration (C-SPMsat), a semi-analytical algorithm was regionally calibrated using local in-situ data, which improved the accuracy of satellite-derived SPM concentration by similar to 20% (MRD). Analysis of SPM concentration for two consecutive years (2019, 2020) revealed strong seasonality of SPM in Adventfjorden.
Highest estimated SPM concentrations and river plume extent (% of fjord with C-SPMsat > 30 mg L-1) occurred during June, July, and August.
Concurrently, we observed a strong relationship between river plume extent and average air temperature over the 24 h prior to the observation (R-2 = 0.69).
Considering predicted changes to environmental conditions in the Arctic region, this study highlights the importance of the rapidly changing environmental parameters and the significance of remote sensing in analysing fluxes in light attenuating particles, especially in the coastal Arctic Ocean.
KW - ocean colour
KW - coastal darkening
KW - SPM
KW - sediment plumes
KW - Arctic coast
KW - remote sensing
KW - regional tuning
KW - coastal ecosystems;
KW - land-ocean-interaction
KW - riverine inputs
Y1 - 2022
U6 - https://doi.org/10.3390/rs14133123
SN - 2072-4292
VL - 14
IS - 13
PB - MDPI
CY - Basel
ER -
TY - JOUR
A1 - Veh, Georg
A1 - Lützow, Natalie
A1 - Kharlamova, Varvara
A1 - Petrakov, Dmitry
A1 - Hugonnet, Romain
A1 - Korup, Oliver
T1 - Trends, Breaks, and Biases in the Frequency of Reported Glacier Lake Outburst Floods
JF - Earth's Future
N2 - Thousands of glacier lakes have been forming behind natural dams in high mountains following glacier retreat since the early 20th century. Some of these lakes abruptly released pulses of water and sediment with disastrous downstream consequences. Yet it remains unclear whether the reported rise of these glacier lake outburst floods (GLOFs) has been fueled by a warming atmosphere and enhanced meltwater production, or simply a growing research effort. Here we estimate trends and biases in GLOF reporting based on the largest global catalog of 1,997 dated glacier-related floods in six major mountain ranges from 1901 to 2017. We find that the positive trend in the number of reported GLOFs has decayed distinctly after a break in the 1970s, coinciding with independently detected trend changes in annual air temperatures and in the annual number of field-based glacier surveys (a proxy of scientific reporting). We observe that GLOF reports and glacier surveys decelerated, while temperature rise accelerated in the past five decades. Enhanced warming alone can thus hardly explain the annual number of reported GLOFs, suggesting that temperature-driven glacier lake formation, growth, and failure are weakly coupled, or that outbursts have been overlooked. Indeed, our analysis emphasizes a distinct geographic and temporal bias in GLOF reporting, and we project that between two to four out of five GLOFs on average might have gone unnoticed in the early to mid-20th century. We recommend that such biases should be considered, or better corrected for, when attributing the frequency of reported GLOFs to atmospheric warming.
Y1 - 2022
U6 - https://doi.org/10.1029/2021EF002426
SN - 2328-4277
VL - 10
SP - 1
EP - 14
PB - Wiley-Blackwell
CY - Hoboken, New Jersey
ET - 3
ER -
TY - JOUR
A1 - Heistermann, Maik
A1 - Bogena, Heye
A1 - Francke, Till
A1 - Güntner, Andreas
A1 - Jakobi, Jannis
A1 - Rasche, Daniel
A1 - Schrön, Martin
A1 - Döpper, Veronika
A1 - Fersch, Benjamin
A1 - Groh, Jannis
A1 - Patil, Amol
A1 - Pütz, Thomas
A1 - Reich, Marvin
A1 - Zacharias, Steffen
A1 - Zengerle, Carmen
A1 - Oswald, Sascha
T1 - Soil moisture observation in a forested headwater catchment: combining a dense cosmic-ray neutron sensor network with roving and hydrogravimetry at the TERENO site Wüstebach
JF - Earth system science data : ESSD
N2 - Cosmic-ray neutron sensing (CRNS) has become an effective method to measure soil moisture at a horizontal scale of hundreds of metres and a depth of decimetres. Recent studies proposed operating CRNS in a network with overlapping footprints in order to cover root-zone water dynamics at the small catchment scale and, at the same time, to represent spatial heterogeneity. In a joint field campaign from September to November 2020 (JFC-2020), five German research institutions deployed 15 CRNS sensors in the 0.4 km2 Wüstebach catchment (Eifel mountains, Germany). The catchment is dominantly forested (but includes a substantial fraction of open vegetation) and features a topographically distinct catchment boundary. In addition to the dense CRNS coverage, the campaign featured a unique combination of additional instruments and techniques: hydro-gravimetry (to detect water storage dynamics also below the root zone); ground-based and, for the first time, airborne CRNS roving; an extensive wireless soil sensor network, supplemented by manual measurements; and six weighable lysimeters. Together with comprehensive data from the long-term local research infrastructure, the published data set (available at https://doi.org/10.23728/b2share.756ca0485800474e9dc7f5949c63b872; Heistermann et al., 2022) will be a valuable asset in various research contexts: to advance the retrieval of landscape water storage from CRNS, wireless soil sensor networks, or hydrogravimetry; to identify scale-specific combinations of sensors and methods to represent soil moisture variability; to improve the understanding and simulation of land–atmosphere exchange as well as hydrological and hydrogeological processes at the hillslope and the catchment scale; and to support the retrieval of soil water content from airborne and spaceborne remote sensing platforms.
Y1 - 2022
U6 - https://doi.org/10.5194/essd-14-2501-2022
SN - 1866-3516
SN - 1866-3508
VL - 14
IS - 5
SP - 2501
EP - 2519
PB - Copernicus
CY - Katlenburg-Lindau
ER -
TY - JOUR
A1 - Heistermann, Maik
A1 - Francke, Till
A1 - Scheiffele, Lena
A1 - Petrova, Katya Dimitrova
A1 - Budach, Christian
A1 - Schrön, Martin
A1 - Trost, Benjamin
A1 - Rasche, Daniel
A1 - Güntner, Andreas
A1 - Doepper, Veronika
A1 - Förster, Michael
A1 - Köhli, Markus
A1 - Angermann, Lisa
A1 - Antonoglou, Nikolaos
A1 - Zude, Manuela
A1 - Oswald, Sascha
T1 - Three years of soil moisture observations by a dense cosmic-ray neutron sensing cluster at an agricultural research site in north-east Germany
JF - Earth system science data : ESSD
N2 - Cosmic-ray neutron sensing (CRNS) allows for the estimation of root-zone soil water content (SWC) at the scale of several hectares. In this paper, we present the data recorded by a dense CRNS network operated from 2019 to 2022 at an agricultural research site in Marquardt, Germany - the first multi-year CRNS cluster. Consisting, at its core, of eight permanently installed CRNS sensors, the cluster was supplemented by a wealth of complementary measurements: data from seven additional temporary CRNS sensors, partly co-located with the permanent ones; 27 SWC profiles (mostly permanent); two groundwater observation wells; meteorological records; and Global Navigation Satellite System reflectometry (GNSS-R). Complementary to these continuous measurements, numerous campaign-based activities provided data by mobile CRNS roving, hyperspectral im-agery via UASs, intensive manual sampling of soil properties (SWC, bulk density, organic matter, texture, soil hydraulic properties), and observations of biomass and snow (cover, depth, and density). The unique temporal coverage of 3 years entails a broad spectrum of hydro-meteorological conditions, including exceptional drought periods and extreme rainfall but also episodes of snow coverage, as well as a dedicated irrigation experiment. Apart from serving to advance CRNS-related retrieval methods, this data set is expected to be useful for vari-ous disciplines, for example, soil and groundwater hydrology, agriculture, or remote sensing. Hence, we show exemplary features of the data set in order to highlight the potential for such subsequent studies. The data are available at doi.org/10.23728/b2share.551095325d74431881185fba1eb09c95 (Heistermann et al., 2022b).
Y1 - 2023
U6 - https://doi.org/10.5194/essd-15-3243-2023
SN - 1866-3508
SN - 1866-3516
VL - 15
IS - 7
SP - 3243
EP - 3262
PB - Copernics Publications
CY - Katlenburg-Lindau
ER -