LOOP 4 at Lillebæk on Fyn is an approx. 470 ha. In the glacial landscape, the terrain is slightly sloping towards the sea, Storebælt. The soil layers consist predominantly of moraine clay with elements of meltwater sand and clay. In the deeper layers, there is a continuous layer of sand. The dominant soil types in the catchment are classified as sand-mixed clay (86%) and clay sand (4%). Forest accounts for 2% of the catchment area, 89% is used for intensive farming, and 9% of the area is roads, cities etc.