Impacts of changing climate and topography on snow cover variability of Parvati River Basin, western Himalayas, India.

Snow cover is an essential element of the Himalayan region (Third Pole), and it represents the impacts induced by climate change. Recently, studies have reported significant variations in the Himalayan snow cover area, which may impact the livelihood of a large portion of the global population. Therefore, in this study, efforts were made to estimate the association between key climate stressors (CSs), i.e., temperature and precipitation, topography, and temporal variability of snow cover area (SCA) in the Parvati River basin (PRB) of the Indian western Himalayas. In this regard, the PRB has been classified into different elevation zones, i.e., zone I to zone V, ranging from 1100 to 6200 amsl. The databases such as MODIS, MEERA-2, and ASTER DEM V2 have been used to estimate the changes in the SCA and the CSs with changes in elevation and seasons. The linear regression analysis of the dataset from 2001 to 2017 revealed a significant association and increasing trend in the SCA of zone III. However, a significant association could not be established between the elevation and the SCA for the rest of the zones. A zonal seasonal trend investigation of the SCA observed an increasing trend in zones IV and V during the summer season due to a momentous rise in snowfall and a decline in temperature. The SCA has shown a significant declining trend only during the monsoon season in zones IV and V, which is due to a strong negative relationship between the SCA and the temperature of the region. These results demonstrate the amount of SCA in zones of high elevation of the PRB has been declining at an alarming rate, which could negatively influence glaciers' retreat in the near future. Hence, it can be estimated that the outcomes of the study will act as a base for future studies, regional policy formulation, and climate modelling that can further prevent future drastic or extreme events.