Evaluating the Responses of Streamflow under Future Climate Change Scenarios in a Western Indian Himalaya Watershed

摘要

Water resources in the mountain ecosystem are very important in supporting the livelihood of the population. It is crucial to assess changes in climate variables and their effect on streamflow to determine water availability in a watershed. Thus, this paper aimed to understand the changes in climate variables and their effect on streamflow in the upper Beas basin of Western Himalaya by mid-21st century. The topographical details of the basin were taken from Cartosat digital elevation model (DEM). Non-parametric methods were applied for climate variability analysis of Manali, Bhuntar and Katrain stations. The decision tree technique was applied to the Landsat image in making land use/land cover (LULC) map of the study area. Soil and Water Assessment Tool (SWAT) was employed to simulate the future streamflow under different climate change scenarios. SWAT was calibrated and validated using observed streamflow data of Thalout station. The study found a rise (0.31% to 14.18%) in mean annual streamflow while seasonal flow was more pronounced in pre-monsoon and monsoon in the near future. However, there would be lesser streamflow in the latter half of this century due to reduction in snow cover consequent to rise in temperature. This will adversely affect the irrigation potential and hydroelectricity generation capacity in the region.