Bro — Ground water mirror depth Model for the Netherlands (50x50 meters grid)

This BRO registration object, the ‘Model Groundwater Mirror Depth’, is land cover and relates to the non-paved, unbuilt part of the Netherlands. The groundwater depth model is based on measured groundwater mirror depths and area-covering auxiliary information such as ground level height models. Several statistically calculated characteristics of the dynamics (seasonal fluctuations) of groundwater level depth in the Netherlands are included. The level of the (freatic) groundwater level is here in relation to ground level and not to a fixed reference level (usually NAP). We are talking about a model of groundwater mirror depth because the area-wide forecasts (interpolations) are calculated using statistical methods. For this purpose, observed groundwater mirror depths and related information from different data sources have been used. The main dynamic characteristics are the average highest (lowest depth) and average lowest groundwater level (largest depth) and spring ground water level (GHG, GLG and GVG). These data are again used for a classification in Groundwater Steps (Gt’s) as we know it in the Netherlands and were included in previous soil maps. The groundwater steps are now included in this dataset. The accuracy of the groundwater mirror depth characteristics is also part of the model, in the form of a large number of (300 or more) realisations (drawings) from the probability distributions of these characteristics. By including realisations (drawings) from the probability distribution in the model, the BRO user of the model groundwater mirror depth does not have to make assumptions about the form of the probability distribution.