@article{DelgadoMerzApel2014, author = {Delgado, Jose Miguel Martins and Merz, Bruno and Apel, Heiko}, title = {Projecting flood hazard under climate change: an alternative approach to model chains}, series = {Natural hazards and earth system sciences}, volume = {14}, journal = {Natural hazards and earth system sciences}, number = {6}, publisher = {Copernicus}, address = {G{\"o}ttingen}, issn = {1561-8633}, doi = {10.5194/nhess-14-1579-2014}, pages = {1579 -- 1589}, year = {2014}, abstract = {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.}, language = {en} } @article{MerzAertsArnbjergNielsenetal.2014, author = {Merz, Bruno and Aerts, Jeroen C. J. H. and Arnbjerg-Nielsen, Karsten and Baldi, M. and Becker, Andrew C. and Bichet, A. and Bloeschl, G. and Bouwer, Laurens M. and Brauer, Achim and Cioffi, F. and Delgado, Jose Miguel Martins and Gocht, M. and Guzzetti, F. and Harrigan, S. and Hirschboeck, K. and Kilsby, C. and Kron, W. and Kwon, H. -H. and Lall, U. and Merz, R. and Nissen, K. and Salvatti, P. and Swierczynski, Tina and Ulbrich, U. and Viglione, A. and Ward, P. J. and Weiler, M. and Wilhelm, B. and Nied, Manuela}, title = {Floods and climate: emerging perspectives for flood risk assessment and management}, series = {Natural hazards and earth system sciences}, volume = {14}, journal = {Natural hazards and earth system sciences}, number = {7}, publisher = {Copernicus}, address = {G{\"o}ttingen}, issn = {1561-8633}, doi = {10.5194/nhess-14-1921-2014}, pages = {1921 -- 1942}, year = {2014}, abstract = {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.}, language = {en} }