Spatiotemporal Trends of Snow Cover under Climate Change Using Landsat Imagery: A Case Study of the Astore Region, Western Himalaya, Pakistan

The Upper Indus Basin is a significant freshwater resource for Pakistan’s irrigation system, with approximately half of its annual water resources are produced from glacier and snow nourished basin within the Himalaya, Karakorum, and Hindu Kush (HKH) region. The basin is increasingly vulnerable to climate change, making it important to study and assess the spatiotemporal changes of snow cover area (SCA) and their relationships with climatic factors for actual water resource management. This study is focused on the sub-basin of Upper Indus Basin Astore region, using Landsat imagery from 1998 to 2023 to calculate SCA during the summer season through the indices of the Normalized Difference Snow Index. Climatic variables, with precipitation and temperature were downloaded from NASA’s Prediction of worldwide energy resources (POWER) dataset. Results illustrate a significant decline in SCA at a rate of -4.92 km2 per year, which is associated with increasing mean annual temperature and decreasing precipitation. These findings confirm that increasing temperature and reduced precipitation are contributing to the reduction of snow cover in Astore. This study highlights the significance of regional scale studies to know the consequence of climate change on change in snow cover within the Upper Indus Basin.