A system perspective on flood risk in polder drainage canal systems

Abstract

A major part of the Netherlands is prone to flooding: roughly 60%. Therefore, a large system of flood defences protects the country from flooding. These flood defences are divided into primary and regional flood defence systems. Primary flood defences protect areas against catastrophical flooding events from the sea, big lakes and major rivers, whereas regional flood defences protect areas against relatively small flooding events. This dissertation focusses on regional flood defences, and in particular polder drainage canal levees (in Dutch: boezemkaden). These canal levees are located along polder drainage canals (in Dutch: boezemkanalen), which discharge excess water from rainfall and seepage from the polder to the sea or the major rivers. Canal levees play a major role in preventing regional flooding, and are assessed periodically, to keep the risk of levee failure at an acceptable level....