Technical and hydrological effects across scales and thresholds of polders, dams and levees

Abstract

Floods are one of the natural hazards that can cause large economic damage and endanger human lives. Additionally, climate change could affect the frequency and magnitudes of floods around the globe. Therefore, flood protection is needed in order to reduce flood risk. Numerous options are available for flood protection. Each measure should be thoroughly evaluated using a combination of hydrological and hydraulic models with the consideration of their uncertainty. This chapter presents basic information about main hydrological, hydraulic, flood protection, and flood risk concepts. Numerous examples are presented showing positive and negative effects of different measures. The importance of hydrologic and hydraulic feedback between river reaches should be noted. Therefore, a holistic catchment-scale approach is needed. It should be noted that even non-structural measures require some construction work and that every measure or a combination of measures should be evaluated from the cost-benefit point of view.