The influence of floodplain compartmentalization on flood risk within the Rhine - Meuse delta

Abstract

The present compartmentalization layout within the river polders in the Dutch Rhine-Meuse delta is the result of abandonment and partially removal of secondary dikes and the construction of modern infrastructure embankments. These structures will guide the flow of water in case the polder would inundate. Through the application of a 2D flood propagation model in the polder "Land van Maas en Waal" this study explores whether restoration or removal of old dike remnants would contribute to a reduction of the risk and damage during an inundation. A systematic set of 28 flood scenarios was simulated and for each scenario an additional damage and risk assessment was carried out. It is concluded that a simple removal or total restoration will not reduce flood damage, but that this must be achieved by a strategic compartment plan. With such a plan old dike remnants and present embankments can be used to keep water away from vulnerable and valuable areas for as long as possible and to guide the floodwater to areas that are considered less vulnerable