The water table depth model is part of the National Key Registry of the Subsurface (BRO). It consists of a set of water table depth characteristics that represent the long term averaged fluctuation of water table depth. These statistics are the mean smallest water table depth (GHG), the means greatest water table depth (GLG) and the water table class (Gt). The water table class used to be part of another BRO registration object, i.e., the Soil Map of the Netherlands scale 1:50000. For applications in ecology for instance, the average spring water table depth (GVG) is now also part of the WDM.
Applications and quality
Applications of the water table depth are for instance, spatial planning, calculation of crop growth reduction, habitat restoration/creation, designation of special areas of conservation under the EU Habitats Directive, designation of Natura 2000 areas, substantiation of derogation request under the European Nitrates Directive, and the assessment of the effectiveness and risks of plant protection products.
The water table depth model is a spatial statistical model based on many thousands of observations. It is therefore possible to also derive maps of the accuracy of the results. This information is also part of the WDM.
Download the documents concerning the BRO Water table Depth Model (ZIP in Dutch - 14.7MB).