MONITORING DECADAL PRECIPITATION VARIABILITY IN UPPERINDUS BASIN, PAKISTAN

Abstract

Upper Indus Basin (UIB) is critical for Pakistan’s economy as it is glacial in composition and snow melt that provides 80% of the fresh water to Indus River. Decadal fluctuations in the precipitation in UIB during 1980-2010, using interpolation technique in Arc Map were explored in present study. The results provided a positive correlation between the winter precipitation and summer runoff in middle elevation basins of UIB. The map of decadal difference of mean annual rainfall (1980-2010), prepared in Arc Geographic Information System 9.0, revealed that around Gilgit, Skardu, Astore, Chilas and Bunji, was found the least difference in mean annual rainfall, i.e. of -1.68 to-2.14mm, whereas area around Kakul experienced maximum rainfall decadal difference ranged from-13.63 to -17.45mm. The study suggested that south of lesser Himalayan areas experienced maximum rainfall variability during the period 1980-2010, whereas, lesser variability in north of Himalayan areas inferred safer addition in fresh water in Indus from its glacial reserve.