Groundwater vulnerability map: the Coating

The map of the vulnerability of the groundwater of the Flemish Region can be defined as a map of the level of risk of contamination of the groundwater in the upper water layer by substances penetrating the ground from the soil, taking into account only static parameters. This map can later serve as a basis for a more detailed map, which can also include dynamic and hydrochemical factors. However, where the top recoverable aquifer is naturally salinized (>>the coating: A coating is considered to be the layer that occurs above the aquifer. Taking into account the excavation for structures, canals, canals, etc., the coating must be at least 5 m thick to provide sufficient protection. If it is less than 5 m thick, it is assumed that a coating is missing. A sandy formation is not considered a protective coating. What determines the classification of the coatings are the nature of the rock, the thickness and the hydraulic resistance. There are three classes: *no coating (less than 5 meters and/or sandy); *a loamy coating; *a clayy coating.