An assessment of the potential impacts of climatic warming on glacier-fed river flow in the Himalaya.

A regional hydro-glaciological model has been developed to assess the potential impacts of climatic warming on glacier-fed river flows in the Indus and Ganges basins. The model, applied at a 20 km x 20 km grid resolution, considers glaciers contributing runoff to a cell as a single idealized glacier that is allowed to recede through time. Using 1961-1990 climate data as input, baseline flow estimates were derived for every stretch of river in either basin. A transient warming scenario of +0.06°C years -1 was then imposed for 100 years from an arbitrary start-date of 1991. Comparison of results at 10 sites in two representative areas suggest the impacts of such climatic warming are similar regionally, with estimates of future decadal mean flows continually increasing at 1-4% per decade, relative to baseline, at most sites considered. Flows peaked at only two of the sites several decades into the model run.