Classification
GTAK - Hydrogeology
5
UPVC - Groundwater
5
GCAA - Regional geology - Germany
2
UPK - Water resources, water supply
2
UPVF - Surface waters - streams, rivers, lakes
2
UHN - Landscape ecology
1
UPC - Water - general aspects
1
UPN - Water protection, water quality, clean water
1
UPP - Water pollution
1
UPT - Water pollution control and measurement
1
UPV - Special waters
1