TY - JOUR A1 - Farrag, Mostafa A1 - Brill, Fabio Alexander A1 - Nguyen, Viet Dung A1 - Sairam, Nivedita A1 - Schröter, Kai A1 - Kreibich, Heidi A1 - Merz, Bruno A1 - de Bruijn, Karin M. A1 - Vorogushyn, Sergiy T1 - On the role of floodplain storage and hydrodynamic interactions in flood risk estimation JF - Hydrological sciences journal = Journal des sciences hydrologiques N2 - Hydrodynamic interactions, i.e. the floodplain storage effects caused by inundations upstream on flood wave propagation, inundation areas, and flood damage downstream, are important but often ignored in large-scale flood risk assessments. Although new methods considering these effects sometimes emerge, they are often limited to a small or meso scale. In this study, we investigate the role of hydrodynamic interactions and floodplain storage on flood hazard and risk in the German part of the Rhine basin. To do so, we compare a new continuous 1D routing scheme within a flood risk model chain to the piece-wise routing scheme, which largely neglects floodplain storage. The results show that floodplain storage is significant, lowers water levels and discharges, and reduces risks by over 50%. Therefore, for accurate risk assessments, a system approach must be adopted, and floodplain storage and hydrodynamic interactions must carefully be considered. KW - hydrodynamic interactions KW - derived flood risk analysis KW - flood modelling; KW - Rhine basin Y1 - 2022 U6 - https://doi.org/10.1080/02626667.2022.2030058 SN - 0262-6667 SN - 2150-3435 VL - 67 IS - 4 SP - 508 EP - 534 PB - Routledge, Taylor & Francis Group CY - Abingdon ER - TY - JOUR A1 - Merz, Bruno A1 - Nguyen, Viet Dung A1 - Apel, Heiko A1 - Gerlitz, Lars A1 - Schröter, Kai A1 - Steirou, Eva Styliani A1 - Vorogushyn, Sergiy T1 - Spatial coherence of flood-rich and flood-poor periods across Germany JF - Journal of hydrology N2 - Despite its societal relevance, the question whether fluctuations in flood occurrence or magnitude are coherent in space has hardly been addressed in quantitative terms. We investigate this question for Germany by analysing fluctuations in annual maximum series (AMS) values at 68 discharge gauges for the common time period 1932-2005. We find remarkable spatial coherence across Germany given its different flood regimes. For example, there is a tendency that flood-rich/-poor years in sub-catchments of the Rhine basin, which are dominated by winter floods, coincide with flood-rich/-poor years in the southern sub-catchments of the Danube basin, which have their dominant flood season in summer. Our findings indicate that coherence is caused rather by persistence in catchment wetness than by persistent periods of higher/lower event precipitation. Further, we propose to differentiate between event-type and non-event-type coherence. There are quite a number of hydrological years with considerable nonevent-type coherence, i.e. AMS values of the 68 gauges are spread out through the year but in the same magnitude range. Years with extreme flooding tend to be of event-type and non-coherent, i.e. there is at least one precipitation event that affects many catchments to various degree. Although spatial coherence is a remarkable phenomenon, and large-scale flooding across Germany can lead to severe situations, extreme magnitudes across the whole country within one event or within one year were not observed in the investigated period. (C) 2018 Elsevier B.V. All rights reserved. KW - Flood timing KW - Spatial coherence KW - Flood regimes KW - Climate variability KW - Catchment wetness Y1 - 2018 U6 - https://doi.org/10.1016/j.jhydrol.2018.02.082 SN - 0022-1694 SN - 1879-2707 VL - 559 SP - 813 EP - 826 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Nied, Manuela A1 - Schröter, Kai A1 - Lüdtke, Stefan A1 - Nguyen, Viet Dung A1 - Merz, Bruno T1 - What are the hydro-meteorological controls on flood characteristics? JF - Journal of hydrology N2 - Flood events can be expressed by a variety of characteristics such as flood magnitude and extent, event duration or incurred loss. Flood estimation and management may benefit from understanding how the different flood characteristics relate to the hydrological catchment conditions preceding the event and to the meteorological conditions throughout the event. In this study, we therefore propose a methodology to investigate the hydro-meteorological controls on different flood characteristics, based on the simulation of the complete flood risk chain from the flood triggering precipitation event, through runoff generation in the catchment, flood routing and possible inundation in the river system and floodplains to flood loss. Conditional cumulative distribution functions and regression tree analysis delineate the seasonal varying flood processes and indicate that the effect of the hydrological pre-conditions, i.e. soil moisture patterns, and of the meteorological conditions, i.e. weather patterns, depends on the considered flood characteristic. The methodology is exemplified for the Elbe catchment. In this catchment, the length of the build-up period, the event duration and the number of gauges undergoing at least a 10-year flood are governed by weather patterns. The affected length and the number of gauges undergoing at least a 2-year flood are however governed by soil moisture patterns. In case of flood severity and loss, the controlling factor is less pronounced. Severity is slightly governed by soil moisture patterns whereas loss is slightly governed by weather patterns. The study highlights that flood magnitude and extent arise from different flood generation processes and concludes that soil moisture patterns as well as weather patterns are not only beneficial to inform on possible flood occurrence but also on the involved flood processes and resulting flood characteristics. KW - Flood KW - Flood duration KW - Flood magnitude KW - Flood loss KW - Soil moisture patterns KW - Antecedent conditions KW - Weather patterns KW - Large basins Y1 - 2017 U6 - https://doi.org/10.1016/j.jhydrol.2016.12.003 SN - 0022-1694 SN - 1879-2707 VL - 545 SP - 310 EP - 326 PB - Elsevier CY - Amsterdam ER -