Effects of levee cover strength on flood mapping in the case of levee breach due to overtopping |
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| Authors: | Maurizio Mazzoleni Francesco Dottori Luigia Brandimarte Shewandagn Tekle Mario L V Martina |
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| Institution: | 1. Unesco-IHE Institute for Water Education, Integrated Water Systems and Governance department, Delft, The Netherlands;2. European Commission, Joint Research Centre (JRC), Directorate for Space, Security and Migration, Ispra, Italy;3. KTH Royal Institute of Technology, Department of Civil and Architectural Engineering, Stockholm, Sweden;4. IUSS, School of Advanced Study of Pavia, Department of Uncertainty and Risk Assessment, Pavia, Italy |
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| Abstract: | The reliability of a levee system is a crucial factor in flood risk management. In this study we present a probabilistic methodology to assess the effects of levee cover strength on levee failure probability, triggering time, flood propagation and consequent impacts on population and assets. A method for determining fragility curves is used in combination with the results of a one-dimensional hydrodynamic model to estimate the conditional probability of levee failure in each river section. Then, a levee breach model is applied to calculate the possible flood hydrographs, and for each breach scenario a two-dimensional hydrodynamic model is used to estimate flood hazard (flood extent and timing, maximum water depths) and flood impacts (economic damage and affected population) in the areas at risk along the river reach. We show an application for levee overtopping and different flood scenarios for a 98 km reach of the lower Po River in Italy. The results show how different design solutions for the levee cover can influence the probability of levee failure and the consequent flood scenarios. In particular, good grass cover strength can significantly delay levee failure and reduce maximum flood depths in the flood-prone areas, thus helping the implementation of flood risk management actions. EDITOR D. KoutsoyiannisASSOCIATE EDITOR A. Viglione |
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| Keywords: | levee breach overtopping levee cover strength flood propagation Po River |
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