Salting map groundwater 1974

The salinisation map shows the depth of the interface between fresh and salt groundwater in the coastal and polder areas. The depth is compared to the ground level for the polders. For the dunes, the salinisation map shows an underestimation as the variable relief in this area is not taken into account. Some caution is therefore advised here when interpreting the map in the dune area. The eastern border of the salinisation map of ‘North Flanders’ is formed by the Scheldt. However, the silencing area continues on the right bank, but it has not been detailed to date. The delimitation of the isolated area on the right bank is shown on the vulnerability map of the province of Antwerp (De Breuck et al., 1986). For the sake of completeness, this area was included in the salinisation map on DOV and marked with a green shading (divided — no dates). The interface between fresh and salt groundwater was defined by De Breuck et al. (1974) as a groundwater with a total dissolved solids content (TDS) of 1,500 ppm (or mg/l). As can be derived from the map, freshwater lenses are mainly pronounced under dune and creek areas. These relief forms generally consist of well-permeable deposits so that rainwater infiltrates easily and freshwater lenses can develop. However, the fragile balance between fresh and salt groundwater can be profoundly disturbed by anthropogenic activities.