Kartering grondwaterspiegeldiepte in de provincie Flevoland: Actualisatie van een deel van het Grondwaterspiegeldieptemodel (WDM) voor de Basisregistratie Ondergrond (BRO)

The aim of this project is to make up-to-date maps of water table depth characteristics for the province of Flevoland and to quantify the accuracy of the maps. This project contributes to the ongoing development of the Water Table Depth Model (WDM) for the whole country, which has been available since 2022 from the National Key Registry of the Subsurface (BRO). The WDM has many uses, including for spatial and land use planning, calculating crop damage, nature restoration and habitat creation, soil subsidence forecasting, designation of special areas of conservation (EU Habitats Directive), supporting applications for derogation under the EU Nitrates Directive and assessment of the effectiveness and risks of plant protection products. The mapping in Flevoland was based on measurements at locations distributed evenly across the area. In 2018 water table depths were measured at 246 sites. These data were used to make maps of water table depth characteristics. The accuracy of these maps was quantified and the contents of the maps validated by means of cross-validation.