TY  - JOUR
A1  - Delgado, Jose Miguel Martins
A1  - Merz, Bruno
A1  - Apel, Heiko
T1  - Projecting flood hazard under climate change: an alternative approach to model chains
JF  - Natural hazards and earth system sciences
N2  - Flood hazard projections under climate change are typically derived by applying model chains consisting of the following elements: "emission scenario - global climate model - downscaling, possibly including bias correction hydrological model - flood frequency analysis". To date, this approach yields very uncertain results, due to the difficulties of global and regional climate models to represent precipitation. The implementation of such model chains requires major efforts, and their complexity is high.
 We propose for the Mekong River an alternative approach which is based on a shortened model chain: "emission scenario - global climate model - non-stationary flood frequency model". The underlying idea is to use a link between the Western Pacific monsoon and local flood characteristics: the variance of the monsoon drives a non-stationary flood frequency model, yielding a direct estimate of flood probabilities. This approach bypasses the uncertain precipitation, since the monsoon variance is derived from large-scale wind fields which are better represented by climate models. The simplicity of the monsoon-flood link allows deriving large ensembles of flood projections under climate change. We conclude that this is a worthwhile, complementary approach to the typical model chains in catchments where a substantial link between climate and floods is found.
Y1  - 2014
U6  - https://doi.org/10.5194/nhess-14-1579-2014
SN  - 1561-8633
VL  - 14
IS  - 6
SP  - 1579
EP  - 1589
PB  - Copernicus
CY  - Göttingen
ER  - 
TY  - JOUR
A1  - Farinotti, Daniel
A1  - King, Edward C.
A1  - Albrecht, Anika
A1  - Huss, Matthias
A1  - Gudmundsson, Gudmundur Hilmar
T1  - The bedrock topography of Starbuck Glacier, Antarctic Peninsula, as determined by radio-echo soundings and flow modeling
JF  - Annals of glaciology
KW  - Antarctic glaciology
KW  - glaciological instruments and methods
KW  - ground-penetrating radar
KW  - ice-shelf tributary glaciers
KW  - radio-echo sounding
Y1  - 2014
U6  - https://doi.org/10.3189/2014AoG67A025
SN  - 0260-3055
SN  - 1727-5644
VL  - 55
IS  - 67
SP  - 22
EP  - 28
PB  - International Glaciological Society
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Merz, Bruno
A1  - Aerts, Jeroen C. J. H.
A1  - Arnbjerg-Nielsen, Karsten
A1  - Baldi, M.
A1  - Becker, Andrew C.
A1  - Bichet, A.
A1  - Bloeschl, G.
A1  - Bouwer, Laurens M.
A1  - Brauer, Achim
A1  - Cioffi, F.
A1  - Delgado, Jose Miguel Martins
A1  - Gocht, M.
A1  - Guzzetti, F.
A1  - Harrigan, S.
A1  - Hirschboeck, K.
A1  - Kilsby, C.
A1  - Kron, W.
A1  - Kwon, H. -H.
A1  - Lall, U.
A1  - Merz, R.
A1  - Nissen, K.
A1  - Salvatti, P.
A1  - Swierczynski, Tina
A1  - Ulbrich, U.
A1  - Viglione, A.
A1  - Ward, P. J.
A1  - Weiler, M.
A1  - Wilhelm, B.
A1  - Nied, Manuela
T1  - Floods and climate: emerging perspectives for flood risk assessment and management
JF  - Natural hazards and earth system sciences
N2  - Flood estimation and flood management have traditionally been the domain of hydrologists, water resources engineers and statisticians, and disciplinary approaches abound. Dominant views have been shaped; one example is the catchment perspective: floods are formed and influenced by the interaction of local, catchment-specific characteristics, such as meteorology, topography and geology. These traditional views have been beneficial, but they have a narrow framing. In this paper we contrast traditional views with broader perspectives that are emerging from an improved understanding of the climatic context of floods. We come to the following conclusions: (1) extending the traditional system boundaries (local catchment, recent decades, hydrological/hydraulic processes) opens up exciting possibilities for better understanding and improved tools for flood risk assessment and management. (2) Statistical approaches in flood estimation need to be complemented by the search for the causal mechanisms and dominant processes in the atmosphere, catchment and river system that leave their fingerprints on flood characteristics. (3) Natural climate variability leads to time-varying flood characteristics, and this variation may be partially quantifiable and predictable, with the perspective of dynamic, climate-informed flood risk management. (4) Efforts are needed to fully account for factors that contribute to changes in all three risk components (hazard, exposure, vulnerability) and to better understand the interactions between society and floods. (5) Given the global scale and societal importance, we call for the organization of an international multidisciplinary collaboration and data-sharing initiative to further understand the links between climate and flooding and to advance flood research.
Y1  - 2014
U6  - https://doi.org/10.5194/nhess-14-1921-2014
SN  - 1561-8633
VL  - 14
IS  - 7
SP  - 1921
EP  - 1942
PB  - Copernicus
CY  - Göttingen
ER  - 
TY  - JOUR
A1  - Tang, Kam W.
A1  - McGinnis, Daniel F.
A1  - Frindte, Katharina
A1  - Bruchert, Volker
A1  - Grossart, Hans-Peter
T1  - Paradox reconsidered: Methane oversaturation in well-oxygenated lake waters
JF  - Limnology and oceanography
N2  - The widely reported paradox of methane oversaturation in oxygenated water challenges the prevailing paradigm that microbial methanogenesis only occurs under anoxic conditions. Using a combination of field sampling, incubation experiments, and modeling, we show that the recurring mid-water methane peak in Lake Stechlin, northeast Germany, was not dependent on methane input from the littoral zone or bottom sediment or on the presence of known micro-anoxic zones. The methane peak repeatedly overlapped with oxygen oversaturation in the seasonal thermocline. Incubation experiments and isotope analysis indicated active methane production, which was likely linked to photosynthesis and/or nitrogen fixation within the oxygenated water, whereas lessening of methane oxidation by light allowed accumulation of methane in the oxygen-rich upper layer. Estimated methane efflux from the surface water was up to 5 mmol m(-2) d(-1). Mid-water methane oversaturation was also observed in nine other lakes that collectively showed a strongly negative gradient of methane concentration within 0-20% dissolved oxygen (DO) in the bottom water, and a positive gradient within >= 20% DO in the upper water column. Further investigation into the responsible organisms and biochemical pathways will help improve our understanding of the global methane cycle.
Y1  - 2014
U6  - https://doi.org/10.4319/lo.2014.59.1.0275
SN  - 0024-3590
SN  - 1939-5590
VL  - 59
IS  - 1
SP  - 275
EP  - 284
PB  - Wiley
CY  - Waco
ER  - 
TY  - JOUR
A1  - Kneis, David
A1  - Chatterjee, C.
A1  - Singh, R.
T1  - Evaluation of TRMM rainfall estimates over a large Indian river basin (Mahanadi)
JF  - Hydrology and earth system sciences : HESS
N2  - The paper examines the quality of satellite-abased precipitation estimates for the lower Mahanadi River basin (eastern India). The considered data sets known as 3B42 and 3B42-RT (version 7/7A) are routinely produced by the tropical rainfall measuring mission (TRMM) from passive microwave and infrared recordings. While the 3B42-RT data are disseminated in real time, the gauge-aadjusted 3B42 data set is published with a delay of some months. The quality of the two products was assessed in a two-astep procedure. First, the correspondence between the remotely sensed precipitation rates and rain gauge data was evaluated at the subbasin scale. Second, the quality of the rainfall estimates was assessed by analysing their performance in the context of rainfall-arunoff simulation.
 At sub-abasin level (4000 to 16 000 km(2)) the satellite-abased areal precipitation estimates were found to be moderately correlated with the gauge-abased counterparts (R-2 of 0.64-0.74 for 3B42 and 0.59-0.72 for 3B42-RT). Significant discrepancies between TRMM data and ground observations were identified at high-aintensity levels. The rainfall depth derived from rain gauge data is often not reflected by the TRMM estimates (hit rate < 0.6 for ground-abased intensities > 80 mm day(-1)). At the same time, the remotely sensed rainfall rates frequently exceed the gauge-abased equivalents (false alarm ratios of 0.2-0.6). In addition, the real-atime product 3B42-RT was found to suffer from a spatially consistent negative bias.
 Since the regionalisation of rain gauge data is potentially associated with a number of errors, the above results are subject to uncertainty. Hence, a validation against independent information, such as stream flow, was essential. In this case study, the outcome of rainfall-arunoff simulation experiments was consistent with the above-mentioned findings. The best fit between observed and simulated stream flow was obtained if rain gauge data were used as model input (Nash-Sutcliffe index of 0.76-0.88 at gauges not affected by reservoir operation). This compares to the values of 0.71-0.78 for the gauge-djusted TRMM 3B42 data and 0.65-0.77 for the 3B42-RT real-atime data. Whether the 3B42-RT data are useful in the context of operational runoff prediction in spite of the identified problems remains a question for further research.
Y1  - 2014
U6  - https://doi.org/10.5194/hess-18-2493-2014
SN  - 1027-5606
SN  - 1607-7938
VL  - 18
IS  - 7
SP  - 2493
EP  - 2502
PB  - Copernicus
CY  - Göttingen
ER  - 
TY  - JOUR
A1  - Müller, Hans J.
A1  - Beckmann, Felix
A1  - Dobson, David P.
A1  - Hunt, Simon A.
A1  - Lathe, Christian
A1  - Stroncik, Nicole
T1  - New techniques for high pressure falling sphere viscosimetry in DIA-type large volume presses
JF  - High pressure research
KW  - falling sphere viscosimetry
KW  - inelastic properties
KW  - high pressure
KW  - X-radiography
Y1  - 2014
U6  - https://doi.org/10.1080/08957959.2014.950262
SN  - 0895-7959
SN  - 1477-2299
VL  - 34
IS  - 3
SP  - 345
EP  - 354
PB  - Routledge, Taylor & Francis Group
CY  - Abingdon
ER  - 
TY  - JOUR
A1  - Lepetit, Petra
A1  - Viereck, Lothar
A1  - Piper, John D. A.
A1  - Sudo, Masafumi
A1  - Gurel, Ali
A1  - Copuroglu, Ibrahim
A1  - Gruber, Manuela
A1  - Mayer, Bernhard
A1  - Koch, Michael
A1  - Tatar, Orhan
A1  - Gursoy, Halil
T1  - Ar-40/Ar-39 dating of ignimbrites and plinian air-fall layers from Cappadocia, Central Turkey: Implications to chronostratigraphic and Eastern Mediterranean palaeoenvironmental record
JF  - Chemie der Erde : interdisciplinary journal for chemical problems of the geo-sciences and geo-ecology
N2  - Magmatism forming the Central Anatolian Volcanic Province of Cappadocia, central Turkey, records the last phase of Neotethyan subduction after similar to 11 Ma. Thirteen large calc-alkaline ignimbrite sheets form marker bands within the volcano-sedimentary succession (the Urgup Formation) and provide a robust chronostratigraphy for paleoecologic evaluation of the interleaved paleosols. This paper evaluates the chronologic record in the context of the radiometric, magnetostratigraphic and lithostratigraphic controls. Previous inconsistencies relating primarily to K/Ar evidence were reason for the initiation of an integrated study which includes Ar-40/Ar-39 dating, palaeomagnetic and stratigraphic evidence. The newly determined Ar-40/Ar-39-ages (Lepetit, 2010) are in agreement with Ar/Ar and U/Pb data meanwhile published by Pauquette and Le Pennec (2012) and Aydar et al. (2012). The Ar-40/Ar-39-ages restrict the end of the Urgup Formation to the late Miocene. The paleosol sequence enclosed by the ignimbrites is thus restricted to the late Miocene, the most intense formation of pedogene calcretes correlating with the Messinian Salinity Crisis.
KW  - Ar-40/Ar-39 dating
KW  - Tephrostratigraphy
KW  - Neogene
KW  - Cappadocia
KW  - Turkey
Y1  - 2014
U6  - https://doi.org/10.1016/j.chemer.2014.05.001
SN  - 0009-2819
SN  - 1611-5864
VL  - 74
IS  - 3
SP  - 471
EP  - 488
PB  - Elsevier
CY  - Jena
ER  - 
TY  - JOUR
A1  - Vogel, Kristin
A1  - Riggelsen, Carsten
A1  - Korup, Oliver
A1  - Scherbaum, Frank
T1  - Bayesian network learning for natural hazard analyses
JF  - Natural hazards and earth system sciences
N2  - Modern natural hazards research requires dealing with several uncertainties that arise from limited process knowledge, measurement errors, censored and incomplete observations, and the intrinsic randomness of the governing processes. Nevertheless, deterministic analyses are still widely used in quantitative hazard assessments despite the pitfall of misestimating the hazard and any ensuing risks.
 In this paper we show that Bayesian networks offer a flexible framework for capturing and expressing a broad range of uncertainties encountered in natural hazard assessments. Although Bayesian networks are well studied in theory, their application to real-world data is far from straightforward, and requires specific tailoring and adaptation of existing algorithms. We offer suggestions as how to tackle frequently arising problems in this context and mainly concentrate on the handling of continuous variables, incomplete data sets, and the interaction of both. By way of three case studies from earthquake, flood, and landslide research, we demonstrate the method of data-driven Bayesian network learning, and showcase the flexibility, applicability, and benefits of this approach.
 Our results offer fresh and partly counterintuitive insights into well-studied multivariate problems of earthquake-induced ground motion prediction, accurate flood damage quantification, and spatially explicit landslide prediction at the regional scale. In particular, we highlight how Bayesian networks help to express information flow and independence assumptions between candidate predictors. Such knowledge is pivotal in providing scientists and decision makers with well-informed strategies for selecting adequate predictor variables for quantitative natural hazard assessments.
Y1  - 2014
U6  - https://doi.org/10.5194/nhess-14-2605-2014
SN  - 1561-8633
VL  - 14
IS  - 9
SP  - 2605
EP  - 2626
PB  - Copernicus
CY  - Göttingen
ER  - 
TY  - JOUR
A1  - Stolbova, Veronika
A1  - Martin, P.
A1  - Bookhagen, Bodo
A1  - Marwan, Norbert
A1  - Kurths, Jürgen
T1  - Topology and seasonal evolution of the network of extreme precipitation over the Indian subcontinent and Sri Lanka
JF  - Nonlinear processes in geophysics
N2  - This paper employs a complex network approach to determine the topology and evolution of the network of extreme precipitation that governs the organization of extreme rainfall before, during, and after the Indian Summer Monsoon (ISM) season. We construct networks of extreme rainfall events during the ISM (June-September), post-monsoon (October-December), and pre-monsoon (March-May) periods from satellite-derived (Tropical Rainfall Measurement Mission, TRMM) and rain-gauge interpolated (Asian Precipitation Highly Resolved Observational Data Integration Towards the Evaluation of Water Resources, APHRODITE) data sets. The structure of the networks is determined by the level of synchronization of extreme rainfall events between different grid cells throughout the Indian subcontinent. Through the analysis of various complex-network metrics, we describe typical repetitive patterns in North Pakistan (NP), the Eastern Ghats (EG), and the Tibetan Plateau (TP). These patterns appear during the pre-monsoon season, evolve during the ISM, and disappear during the post-monsoon season. These are important meteorological features that need further attention and that may be useful in ISM timing and strength prediction.
Y1  - 2014
U6  - https://doi.org/10.5194/npg-21-901-2014
SN  - 1023-5809
VL  - 21
IS  - 4
SP  - 901
EP  - 917
PB  - Copernicus
CY  - Göttingen
ER  - 
TY  - JOUR
A1  - Lissner, Tabea Katharina
A1  - Sullivan, C. A.
A1  - Reusser, D. E.
A1  - Kropp, Jürgen
T1  - Determining regional limits and sectoral constraints for water use
JF  - Hydrology and earth system sciences : HESS
N2  - Water is an essential input to the majority of human activities. Often, access to sufficient water resources is limited by quality and infrastructure aspects, rather than by resource availability alone, and each activity has different requirements regarding the nature of these aspects. This paper develops an integrated approach to assess the adequacy of water resources for the three major water users: the domestic, agricultural and industrial sectors. Additionally, we include environmental water requirements. We first outline the main determinants of water adequacy for each sector. Subsequently, we present an integrated approach using fuzzy logic, which allows assessing sector-specific as well as overall water adequacy. We implement the approach in two case study settings to exemplify the main features of the approach. Using results from two climate models and two forcing RCPs (representative concentration pathways), as well as population projections, we further assess the impacts of climate change in combination with population growth on the adequacy of water resources. The results provide an important step forward in determining the most relevant factors, impeding adequate access to water, which remains an important challenge in many regions of the world. The methodology allows one to directly identify the factors that are most decisive in determining the adequacy of water in each region, pointing towards the most efficient intervention points to improve conditions. Our findings underline the fact that, in addition to water volumes, water quality is a limitation for all sectors and, especially for the environmental sector, high levels of pollution are a threat to water adequacy.
Y1  - 2014
U6  - https://doi.org/10.5194/hess-18-4039-2014
SN  - 1027-5606
SN  - 1607-7938
VL  - 18
IS  - 10
SP  - 4039
EP  - 4052
PB  - Copernicus
CY  - Göttingen
ER  -