BE 1: Identifying the salinization of groundwater in the (Western) Flemish coastal area by collecting airborne electromagnetic data
Responsible beneficiary: Flanders Environment Agency
Groundwater in the Belgian western coastal plain is saline by origin, making sure fresh, salt and brackish groundwater are found there. This fresh-salt distribution was mapped in the 60s and 70s and published in a so-called 'salinity map'. However, half a century later, there is a clear need for area-wide mapping of the salinization of the area. The freshwater lenses in the area are frequently used as freshwater supplies. By comparing the newly collected data with the existing salinity map, the autonomous evolution of the freshwater-saltwater distribution can provide a reference in considering the effects of climate change and a rising sea level.
The aim of this action is mapping the fresh-salt water distribution. The proposed project consists of groundwater monitoring, data processing and reporting. While originally, the formatting of the original salinity map involved labor-intensive measuring at ground-level, electromagnetic induction monitoring from out of the air can be used today. A probe attached to a small plane or a helicopter transects the area. The measuring probe transmits a magnetic field and induces an electrical current in the subsoil. This electrical current in turn generates a second electromagnetic field which is detected by the probe. The generated data is processed and checked with the results of already performed research, ultimately leading to an image of the salinization of the subsoil.
This action had led to the following results :
• 3D-image of the subsoil resistivity
• Depth of the fresh-salt water interface
Stakeholders are municipalities, farmers and farmers association