Abstract
Three ice-drainage basins on western Vatnajökull have been delineated with the aid of the first available, accurate ice-surface maps. These basins drain ice towards the major river systems: Tungnaá, Sylgja, and Kaldakvísl, There seems to be an important difference in the location of ice-drainage basins and melt water-drainage basins for the rivers Tungnaá and Sylgja. This is due to the influence of the bedrock topography on the flow of basal water.