Assessing the impacts of climate change on the high altitude snow- and glacier-fed hydrological regimes of Astore and Hunza, the sub-catchments of Upper Indus Basin

Abstract

Abstract Evaluation of the impacts of prevailing climate change on rivers and water resources is significantly important in order to successfully manage water resources, particularly in snow-fed and glacier-fed catchments. The basic aim of this research was to assess the impacts of climatic variability on Astore and Hunza river-flows by employing long-term in-situ hydro-meteorological data. Times-series analysis of high- and low-altitude station data revealed consistent summer cooling, and warming in winter and spring seasons in both Karakoram and western Himalayan basins of Hunza and Astore, respectively. The intensity of these changes was not found to be identical in both basins, i.e. Hunza depicts slightly higher summer cooling rates and slightly lower annual, winter and spring warming rates as compared to Astore. Subsequently, the significant increase in annual precipitation of Hunza was also not found to be identical with Astore precipitation, which shows only a slight increase of precipitation. Notwithstanding, comparable temperature trends were observed at both high- and low-altitude stations; however, on the contrary, precipitation shows a different pattern of behavior, i.e. significantly increased winter precipitation at high-altitude Astore stations was in contrast to the precipitation recorded by low-altitude stations. The study suggested that climate change is significantly influencing the characteristics and hydrological resources of this region.