Description:
Downstream variation in the impact of glacier recession is illustrated in Figure 5, which shows modelled river fows for idealized catchments under climates representative of the western and eastern Himalaya and a 0.06º C per year warming scenario. In the upper parts of the river basins, where glaciers occupy 95% of the catchment area, the impact of glacier shrinkage is large. River discharges increase until mid-century, after which they decline to a base level equal to the annual precipitation totals. When larger catchments are con- sidered, the percentage glacierized area is smaller, and the impact of glacier shrinkage is much reduced. For modelled catchments with an area of 5,000 square km and 1% glacier cover, the impact of deglaciation is barely detectable in the ‘eastern’ area, where there is high monsoon precipitation insummer. The effect is more signifcant in the ‘western’ area with its dry summer, but the downstream decrease in impact is still clearly evident.