The goal of the Imersuaq project is to establish a basis for more precise evaluation of the major hydropower resources in Greenland. Specifically, the largest hydrological basin in west greenland "Taserssiaq" will be studied. The areal distribution of melt rate will be measured. The limits of the hyrological ice sheet basin will be determined by using airborne laser- and iceradar soundings, as well as maps derived from satellite data (ASTER, ERS1-2, SAR).