The delineation of drainage basins on the Greenland ice sheet for mass-balance analyses using a combined modelling and geographical information system approach

Balance fluxes have been calculated for the Greenland ice sheet using a two -dimensional finite difference scheme. They were calculated from a high-res olution digital elevation model (DEM) and mass-balance data for the Greenla nd ice sheet. The method applied assumes that there is a balance between th e net accumulation and the ice Aux at the margins and provides valuable inf ormation about the balance dynamics across the whole ice sheet. The balance fluxes, along with slope and slope direction information from t he DEM were used in a geographical information system to delineate 10 major drainage basins. Each drainage basin can be considered as an independent f low unit and thus the individual mass balance of each basin can be calculat ed independently. Further, the fluxes across the grounding lines of several major outlet glaciers in northern Greenland have been calculated, resultin g in a reassessment of the mass balance of northern Greenland. Copyright (C ) 2000 John Wiley & Sons, Ltd.