TY - JOUR A1 - Bürger, Gerd A1 - Reusser, Dominik A1 - Kneis, David T1 - Early flood warnings from empirical (expanded) downscaling of the full ECMWF Ensemble Prediction System Y1 - 2009 UR - http://www.agu.org/journals/wr/ U6 - https://doi.org/10.1029/2009wr007779 SN - 0043-1397 ER - TY - JOUR A1 - Reusser, Dominik Edwin A1 - Zehe, Erwin T1 - Low-cost monitoring of snow height and thermal properties with inexpensive temperature sensors JF - Hydrological processes N2 - Small, self-recording temperature sensors were installed at several heights along a metal rod at five locations in a case study catchment. For each sensor, the presence or absence of snow cover was determined on the basis of its insulating effect and the resulting reduction of the diurnal temperature oscillations. Sensor coverage was then converted into a time series of snow height for each location. Additionally, cold content was calculated. Snow height and cold content provide valuable information for spring flood prediction. Good agreement of estimated snow heights with reference measurements was achieved and increased discharge in the study catchment coincided with low cold content of the snow cover. The results of the proposed distributed assessment of snow cover and snow state show great potential for (i) flood warning, (ii) assimilation of snow state data and (iii) modelling snowmelt process. KW - snow measurements KW - cold content KW - temperature index approach KW - heat diffusion KW - temperature Y1 - 2011 U6 - https://doi.org/10.1002/hyp.7937 SN - 0885-6087 SN - 1099-1085 VL - 25 IS - 12 SP - 1841 EP - 1852 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Reusser, Dominik Edwin A1 - Zehe, Erwin T1 - Inferring model structural deficits by analyzing temporal dynamics of model performance and parameter sensitivity JF - Water resources research N2 - In this paper we investigate the use of hydrological models as learning tools to help improve our understanding of the hydrological functioning of a catchment. With the model as a hypothetical conceptualization of how dominant hydrological processes contribute to catchment-scale response, we investigate three questions: (1) During which periods does the model (not) reproduce observed quantities and dynamics? (2) What is the nature of the error during times of bad model performance? (3) Which model components are responsible for this error? To investigate these questions, we combine a method for detecting repeating patterns of typical differences between model and observations (time series of grouped errors, TIGER) with a method for identifying the active model components during each simulation time step based on parameter sensitivity (temporal dynamics of parameter sensitivities, TEDPAS). The approach generates a time series of occurrence of dominant error types and time series of parameter sensitivities. A synoptic discussion of these time series highlights deficiencies in the assumptions about the functioning of the catchment. The approach is demonstrated for the Weisseritz headwater catchment in the eastern Ore Mountains. Our results indicate that the WaSiM-ETH complex grid-based model is not a sufficient working hypothesis for the functioning of the Weisseritz catchment and point toward future steps that can help improve our understanding of the catchment. Y1 - 2011 U6 - https://doi.org/10.1029/2010WR009946 SN - 0043-1397 SN - 1944-7973 VL - 47 PB - American Geophysical Union CY - Washington ER - TY - JOUR A1 - Reusser, Dominik Edwin A1 - Buytaert, W. A1 - Zehe, Erwin T1 - Temporal dynamics of model parameter sensitivity for computationally expensive models with the Fourier amplitude sensitivity test JF - Water resources research N2 - The quest for improved hydrological models is one of the big challenges in hydrology. When discrepancies are observed between simulated and measured discharge, it is essential to identify which algorithms may be responsible for poor model behavior. Particularly in complex hydrological models, different process representations may dominate at different moments and interact with each other, thus highly complicating this task. This paper investigates the analysis of the temporal dynamics of parameter sensitivity as a way to disentangle the simulation of a hydrological model and identify dominant parameterizations. Three existing methods (the Fourier amplitude sensitivity test, the extended Fourier amplitude sensitivity test, and Sobol's method) are compared by applying them to a TOPMODEL implementation in a small mountainous catchment in the tropics. For the major part of the simulation period, the three methods give comparable results, while the Fourier amplitude sensitivity test is much more computationally efficient. This method is also applied to the complex hydrological model WaSiM-ETH implemented in the Weisseritz catchment, Germany. A qualitative model validation was performed on the basis of the identification of relevant model components. The validation revealed that the saturation deficit parameterization of WaSiM-ETH is highly susceptible to parameter interaction and lack of identifiability. We conclude that temporal dynamics of model parameter sensitivity can be a powerful tool for hydrological model analysis, especially to identify parameter interaction as well as the dominant hydrological response modes. Finally, an open source implementation of the Fourier amplitude sensitivity test is provided. Y1 - 2011 U6 - https://doi.org/10.1029/2010WR009947 SN - 0043-1397 VL - 47 IS - 4 PB - American Geophysical Union CY - Washington ER - TY - JOUR A1 - Pradhan, Prajal A1 - Reusser, Dominik Edwin A1 - Kropp, Jürgen T1 - Embodied greenhouse gas emissions in Diets JF - PLoS one N2 - Changing food consumption patterns and associated greenhouse gas (GHG) emissions have been a matter of scientific debate for decades. The agricultural sector is one of the major GHG emitters and thus holds a large potential for climate change mitigation through optimal management and dietary changes. We assess this potential, project emissions, and investigate dietary patterns and their changes globally on a per country basis between 1961 and 2007. Sixteen representative and spatially differentiated patterns with a per capita calorie intake ranging from 1,870 to >3,400 kcal/day were derived. Detailed analyses show that low calorie diets are decreasing worldwide, while in parallel diet composition is changing as well: a discernable shift towards more balanced diets in developing countries can be observed and steps towards more meat rich diets as a typical characteristics in developed countries. Low calorie diets which are mainly observable in developing countries show a similar emission burden than moderate and high calorie diets. This can be explained by a less efficient calorie production per unit of GHG emissions in developing countries. Very high calorie diets are common in the developed world and exhibit high total per capita emissions of 3.7-6.1 kg CO2eq./day due to high carbon intensity and high intake of animal products. In case of an unbridled demographic growth and changing dietary patterns the projected emissions from agriculture will approach 20 Gt CO2eq./yr by 2050. Y1 - 2013 U6 - https://doi.org/10.1371/journal.pone.0062228 SN - 1932-6203 VL - 8 IS - 5 PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Pradhan, Prajal A1 - Lüdeke, Matthias K. B. A1 - Reusser, Dominik Edwin A1 - Kropp, Jürgen T1 - Food self-sufficiency across scales: How local can we go? JF - Environmental science & technology N2 - This study explores the potential for regions to shift to a local food supply using food self-sufficiency (FSS) as an indicator. We considered a region food self-sufficient when its total calorie production is enough to meet its demand. For future scenarios, we considered population growth, dietary changes, improved feed conversion efficiency, climate change, and crop yield increments. Starting at the 5' resolution, we investigated FSS from the lowest administrative levels to continents. Globally, about 1.9 billion people are self-sufficient within their 5' grid, while about 1 billion people from Asia and Africa require cross-continental agricultural trade in 2000. By closing yield gaps, these regions can achieve FSS, which also reduces international trade and increases a self-sufficient population in a 5' grid to 2.9 billion. The number of people depending on international trade will vary between 1.5 and 6 billion by 2050. Climate change may increase the need for international agricultural trade by 4% to 16%. Y1 - 2014 U6 - https://doi.org/10.1021/es5005939 SN - 0013-936X SN - 1520-5851 VL - 48 IS - 16 SP - 9463 EP - 9470 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Lissner, Tabea Katharina A1 - Reusser, Dominik Edwin A1 - Schewe, Jacob A1 - Lakes, T. A1 - Kropp, Jürgen T1 - Climate impacts on human livelihoods: where uncertainty matters in projections of water availability JF - Earth system dynamics N2 - Climate change will have adverse impacts on many different sectors of society, with manifold consequences for human livelihoods and well-being. However, a systematic method to quantify human well-being and livelihoods across sectors is so far unavailable, making it difficult to determine the extent of such impacts. Climate impact analyses are often limited to individual sectors (e.g. food or water) and employ sector-specific target measures, while systematic linkages to general livelihood conditions remain unexplored. Further, recent multi-model assessments have shown that uncertainties in projections of climate impacts deriving from climate and impact models, as well as greenhouse gas scenarios, are substantial, posing an additional challenge in linking climate impacts with livelihood conditions. This article first presents a methodology to consistently measure what is referred to here as AHEAD (Adequate Human livelihood conditions for wEll-being And Development). Based on a trans-disciplinary sample of concepts addressing human well-being and livelihoods, the approach measures the adequacy of conditions of 16 elements. We implement the method at global scale, using results from the Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP) to show how changes in water availability affect the fulfilment of AHEAD at national resolution. In addition, AHEAD allows for the uncertainty of climate and impact model projections to be identified and differentiated. We show how the approach can help to put the substantial inter-model spread into the context of country-specific livelihood conditions by differentiating where the uncertainty about water scarcity is relevant with regard to livelihood conditions - and where it is not. The results indicate that livelihood conditions are compromised by water scarcity in 34 countries. However, more often, AHEAD fulfilment is limited through other elements. The analysis shows that the water-specific uncertainty ranges of the model output are outside relevant thresholds for AHEAD for 65 out of 111 countries, and therefore do not contribute to the overall uncertainty about climate change impacts on livelihoods. In 46 of the countries in the analysis, water-specific uncertainty is relevant to AHEAD. The AHEAD method presented here, together with first results, forms an important step towards making scientific results more applicable for policy decisions. Y1 - 2014 U6 - https://doi.org/10.5194/esd-5-355-2014 SN - 2190-4979 SN - 2190-4987 VL - 5 IS - 2 SP - 355 EP - 373 PB - Copernicus CY - Göttingen ER - TY - JOUR A1 - Fluschnik, Till A1 - Kriewald, Steffen A1 - Ros, Anselmo Garcia Cantu A1 - Zhou, Bin A1 - Reusser, Dominik Edwin A1 - Kropp, Jürgen A1 - Rybski, Diego T1 - The Size Distribution, Scaling Properties and Spatial Organization of Urban Clusters: A Global and Regional Percolation Perspective JF - ISPRS International Journal of Geo-Information N2 - Human development has far-reaching impacts on the surface of the globe. The transformation of natural land cover occurs in different forms, and urban growth is one of the most eminent transformative processes. We analyze global land cover data and extract cities as defined by maximally connected urban clusters. The analysis of the city size distribution for all cities on the globe confirms Zipf’s law. Moreover, by investigating the percolation properties of the clustering of urban areas we assess the closeness to criticality for various countries. At the critical thresholds, the urban land cover of the countries undergoes a transition from separated clusters to a gigantic component on the country scale. We study the Zipf-exponents as a function of the closeness to percolation and find a systematic dependence, which could be the reason for deviating exponents reported in the literature. Moreover, we investigate the average size of the clusters as a function of the proximity to percolation and find country specific behavior. By relating the standard deviation and the average of cluster sizes—analogous to Taylor’s law—we suggest an alternative way to identify the percolation transition. We calculate spatial correlations of the urban land cover and find long-range correlations. Finally, by relating the areas of cities with population figures we address the global aspect of the allometry of cities, finding an exponent δ ≈ 0.85, i.e., large cities have lower densities. Y1 - 2016 U6 - https://doi.org/10.3390/ijgi5070110 SN - 2220-9964 VL - 5 SP - 1543 EP - 1559 PB - MDPI CY - Basel ER - TY - JOUR A1 - Landholm, David M. A1 - Holsten, Anne A1 - Martellozzo, Federico A1 - Reusser, Dominik Edwin A1 - Kropp, Jürgen T1 - Climate change mitigation potential of community-based initiatives in Europe JF - Regional environmental change N2 - There is a growing recognition that a transition to a sustainable low-carbon society is urgently needed. This transition takes place at multiple and complementary scales, including bottom-up approaches such as community-based initiatives (CBIs). However, empirical research on CBIs has focused until now on anecdotal evidence and little work has been done to quantitatively assess their impact in terms of greenhouse gas (GHG) emissions. In this paper, we analyze 38 European initiatives across the food, energy, transport, and waste sectors to address the following questions: How can the GHG reduction potential of CBIs be quantified and analyzed in a systematic manner across different sectors? What is the GHG mitigation potential of CBIs and how does the reduction potential differ across domains? Through the comparison of the emission intensity arising from the goods and services the CBIs provide in relation to a business-as-usual scenario, we present the potential they have across different activities. This constitutes the foundational step to upscaling and further understanding their potential contribution to achieving climate change mitigation targets. Our findings indicate that energy generation through renewable sources, changes in personal transportation, and dietary change present by far the highest GHG mitigation activities analyzed, since they reduce the carbon footprint of CBI beneficiaries by 24%, 11%, and 7%, respectively. In contrast, the potential for some activities, such as locally grown organic food, is limited. The service provided by these initiatives only reduces the carbon footprint by 0.1%. Overall, although the proliferation of CBIs is very desirable from a climate change mitigation perspective it is necessary to stress that bottom-up initiatives present other important positive dimensions besides GHG mitigation. These initiatives also hold the potential of improving community resilience by strengthening local economies and enhancing social cohesion. KW - Greenhouse gas emissions KW - Sustainability transitions KW - Grassroots initiatives KW - Carbon footprint KW - Sustainable lifestyles KW - Low carbon economy Y1 - 2018 U6 - https://doi.org/10.1007/s10113-018-1428-1 SN - 1436-3798 SN - 1436-378X VL - 19 IS - 4 SP - 927 EP - 938 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Rybski, Diego A1 - Reusser, Dominik Edwin A1 - Winz, Anna-Lena A1 - Fichtner, Christina A1 - Sterzel, Till A1 - Kropp, Jürgen T1 - Cities as nuclei of sustainability? JF - Environment and Planning B: Urban Analytics and City Science N2 - We have assembled CO2 emission figures from collections of urban GHG emission estimates published in peer-reviewed journals or reports from research institutes and non-governmental organizations. Analyzing the scaling with population size, we find that the exponent is development dependent with a transition from super- to sub-linear scaling. From the climate change mitigation point of view, the results suggest that urbanization is desirable in developed countries. Further, we compare this analysis with a second scaling relation, namely the fundamental allometry between city population and area, and propose that density might be a decisive quantity too. Last, we derive the theoretical country-wide urban emissions by integration and obtain a dependence on the size of the largest city. KW - Scaling KW - cities KW - climate change KW - development process KW - allometry Y1 - 2017 U6 - https://doi.org/10.1177/0265813516638340 SN - 2399-8083 SN - 2399-8091 VL - 44 IS - 3 SP - 425 EP - 440 PB - Sage Publ. CY - London ER - TY - JOUR A1 - Bronstert, Axel A1 - Creutzfeldt, Benjamin A1 - Gräff, Thomas A1 - Hajnsek, Irena A1 - Heistermann, Maik A1 - Itzerott, Sibylle A1 - Jagdhuber, Thomas A1 - Kneis, David A1 - Lueck, Erika A1 - Reusser, Dominik A1 - Zehe, Erwin T1 - Potentials and constraints of different types of soil moisture observations for flood simulations in headwater catchments JF - Natural hazards : journal of the International Society for the Prevention and Mitigation of Natural Hazards N2 - Flood generation in mountainous headwater catchments is governed by rainfall intensities, by the spatial distribution of rainfall and by the state of the catchment prior to the rainfall, e. g. by the spatial pattern of the soil moisture, groundwater conditions and possibly snow. The work presented here explores the limits and potentials of measuring soil moisture with different methods and in different scales and their potential use for flood simulation. These measurements were obtained in 2007 and 2008 within a comprehensive multi-scale experiment in the Weisseritz headwater catchment in the Ore-Mountains, Germany. The following technologies have been applied jointly thermogravimetric method, frequency domain reflectometry (FDR) sensors, spatial time domain reflectometry (STDR) cluster, ground-penetrating radar (GPR), airborne polarimetric synthetic aperture radar (polarimetric SAR) and advanced synthetic aperture radar (ASAR) based on the satellite Envisat. We present exemplary soil measurement results, with spatial scales ranging from point scale, via hillslope and field scale, to the catchment scale. Only the spatial TDR cluster was able to record continuous data. The other methods are limited to the date of over-flights (airplane and satellite) or measurement campaigns on the ground. For possible use in flood simulation, the observation of soil moisture at multiple scales has to be combined with suitable hydrological modelling, using the hydrological model WaSiM-ETH. Therefore, several simulation experiments have been conducted in order to test both the usability of the recorded soil moisture data and the suitability of a distributed hydrological model to make use of this information. The measurement results show that airborne-based and satellite-based systems in particular provide information on the near-surface spatial distribution. However, there are still a variety of limitations, such as the need for parallel ground measurements (Envisat ASAR), uncertainties in polarimetric decomposition techniques (polarimetric SAR), very limited information from remote sensing methods about vegetated surfaces and the non-availability of continuous measurements. The model experiments showed the importance of soil moisture as an initial condition for physically based flood modelling. However, the observed moisture data reflect the surface or near-surface soil moisture only. Hence, only saturated overland flow might be related to these data. Other flood generation processes influenced by catchment wetness in the subsurface such as subsurface storm flow or quick groundwater drainage cannot be assessed by these data. One has to acknowledge that, in spite of innovative measuring techniques on all spatial scales, soil moisture data for entire vegetated catchments are still today not operationally available. Therefore, observations of soil moisture should primarily be used to improve the quality of continuous, distributed hydrological catchment models that simulate the spatial distribution of moisture internally. Thus, when and where soil moisture data are available, they should be compared with their simulated equivalents in order to improve the parameter estimates and possibly the structure of the hydrological model. KW - Soil moisture KW - Remote sensing KW - Hydrological modelling KW - Flood forecasting KW - Soil moisture measurement comparison Y1 - 2012 U6 - https://doi.org/10.1007/s11069-011-9874-9 SN - 0921-030X SN - 1573-0840 VL - 60 IS - 3 SP - 879 EP - 914 PB - Springer CY - New York ER - TY - JOUR A1 - Gräff, Thomas A1 - Zehe, Erwin A1 - Reusser, Dominik A1 - Lueck, Erika A1 - Schroeder, Boris A1 - Wenk, Gerald A1 - John, Hermann A1 - Bronstert, Axel T1 - Process identification through rejection of model structures in a mid-mountainous rural catchment : observations of rainfall-runoff response, geophysical conditions and model inter-comparison N2 - The intention of the presented study is to gain a better understanding of the mechanisms that caused the bimodal rainfall-runoff responses which occurred up to the mid-1970s regularly in the Schafertal catchment and vanished after the onset of mining activities. Understanding, this process is a first step to understanding the ongoing hydrological change in this area. It is hypothesized that either subsurface stormflow, or fast displacement of groundwater, could cause the second delayed peak. A top-down analysis of rainfall-runoff data, field observations as well as process modelling are combined within a rejectionistic framework. A statistical analysis is used to test whether different predictors. which characterize the forcing. near surface water content and deeper subsurface store, allow the prediction of the type of rainfall-runoff response. Regression analysis is used with generalized linear models Lis they can deal with non-Gaussian error distributions Lis well its a non-stationary variance. The analysis reveals that the dominant predictors are the pre-event discharge (proxy of state of the groundwater store) and the precipitation amount, In the field campaign, the subsurface at a representative hillslope was investigated by means of electrical resistivity tomography in order to identify possible strata as flow paths for subsurface stormflow. A low resistivity in approximately 4 in depth-either due to a less permeable layer or the groundwater surface-was detected. The former Could serve as a flow path for subsurface stormflow. Finally, the physical-based hydrological model CATFLOW and the groundwater model FEFLOW are compared with respect to their ability to reproduce the bimodal runoff responses. The groundwater model is able to reproduce the observations, although it uses only an abstract representation of the hillslopes. Process model analysis as well Lis statistical analysis strongly suggest that fast displacement of groundwater is the dominant process underlying the bimodal runoff reactions. Y1 - 2009 UR - http://www3.interscience.wiley.com/journal/4125/home U6 - https://doi.org/10.1002/Hyp.7171 SN - 0885-6087 ER -