Monitoring and Modeling in the Coastal Aquifer Test Field (CAT-Field) between Bremerhaven and Cuxhaven in the Northern Part of Germany

The Coastal Aquifer Test Field (CAT-Field) between Bremerhaven and Cuxhaven in the north of Germany (see Fig. 1) extends over an area of 1800 km. The center of the CAT-Field, a sandy geest ridge with high groundwater recharge, is surrounded by the extensive drained marsh area and the North Sea coast line. The aquifer consists of quaternary and tertiary sediments. A large quaternary channel system with a basis depth down to -300m NN and a width of 1 to 5 km is arranged parallel to the geest ridge in N-Sdirection. These channels are filled with gravel and covered mostly by clay rich formations. The aquifer is the main fresh water reservoir in the area. In the marsh area the saltwater intrusion up to 10 km distance from the coastline and upconing up to 10 to the marsh area occurs. The work of the Institute for Joint G CAT-Field is related on geophysical groundwater quantity and quality. Mo the groundwater system will be also b gation and interpretation methods.