Risk assessment for coastal erosion

Most risk assessments of coastal erosion in the Netherlands are carried out by the government agencies, knowledge institutes and water boards. The Dutch Ministry of Infrastructure and Water Management assesses the position of the coastline every year to determine where sand nourishments are needed. A reference for this assessment is the base coastline (BKL), which for most of the Netherlands corresponds to the 1990 coastline position. Coastline maps are available for this purpose and can also be used to assess coastal erosion risks in a specific area. The base coastline is periodically revised based on new measurements and changing coastal conditions. The state of the broader coastal area is also considered when planning upcoming sand nourishments.

Water boards assess the safety of the dunes and dykes. Based wave and storm conditions and measured dune profiles, it is assessed if the dunes need to be strengthened. Dune height and width are monitored every year. Data on coastal dune elevation change is available for this purpose. Advanced numerical models are used to predict dune erosion. These models have been validated with laboratory tests and observations of dune erosion during historic erosion events.