Salinisation 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 as far as the polders are concerned. 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 required here when interpreting the map in dune area. The eastern boundary of the salinisation map of "Northern Flanders" is formed by the Scheldt. However, the salinized area continues on the right bank of the chelde, but until now it has not been mapped in detail. The demarcation of salinised area on the right bank of the chelde 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 indicated with a green shading (salted - no data). The interface between fresh and salt groundwater was defined by De Breuck et al. (1974) as a groundwater with a total dissolved solids (TDS) content of 1,500 ppm (or mg/l). As can be deduced from the map, freshwater lenses are mainly pronounced under dune and creek areas. These relief forms generally consist of well-drained deposits that allow rainwater to easily infiltrate and freshwater lenses to develop. However, the delicate balance between fresh and salt groundwater can be profoundly disturbed by anthropogenic activities.