Probabilistic evacuation decision model for river floods in the Netherlands : final report

Large parts of the Netherlands lie below sea level or below water levels of rivers, which could occur. Without protection by flood defenses ca. 65% of the country would be permanently or temporarily flooded, partially by the sea, partially by the rivers. It is expected that the flood hazard will increase in the future because of climatic changes and land subsidence. As a result of climatic changes the sea level will rise and, during the winter, higher river discharges and more precipitation will occur. An evacuation could be an effective measure to reduce or prevent the number of fatalities and a part of economic damage as a result of floods. As high discharges accompanied by high water levels occurred on the river Rhine in 1995 and threatened to inundate several parts of the Netherlands, the authorities decided upon an evacuation of people and cattle. The large-scale evacuation (ca. 240,000 people at risk) was successful. However, the dikes did not breach and no flooding occurred. Therefore the necessity of the evacuation could be questioned.