Examining the glacier-glacial lake interactions of potentially dangerous glacial lakes (PDGLs) under changing climate in Shyok catchment of the Upper Indus Basin

With the ongoing glacier recession, the Himalayan region is witnessing the development of glacial lakes fed by the glacial meltwater. Besides threatening the hydrological regime in the area, the rapid expansion of these lakes at the expense of their feeding glaciers poses a serious risk to the downstream communities in the form of Glacial Lake Outburst Floods, as many of these high-altitude water bodies are vulnerable to this cryospheric disaster under the changing climatic regime. Studying these potentially dangerous glacial lakes (PDGLs) and their feeding glaciers in the context of the changing climate has become crucial in understanding this phenomenon and managing the risk associated with these lakes. The present study focuses on understanding the glacier-lake interactions between the PDGLs and their feeding glaciers under the changing climatic regime. We analyzed the spatio-temporal dynamics of 16 PDGLs, identified in our previous study, and their feeding glaciers for the past three decades (1992-2022), and tried to unravel the relationships between glacier area, glacial lake area, and climatic variables such as temperature and precipitation. The results reveal a rapid expansion of 49.6% in the glacial lake area accompanied by a corresponding glacier recession of 3.27 % and an average terminus retreat of 171 m. The average glacier mass balance was found to be similar to -0.22 m w.e. y(-1) during this period. The minimum temperature (Tmin) revealed statistically significant increasing trend, whereas the annual precipitation (Pcp) in the area revealed a slightly declining trend in this region. The glacial lake area was found to be in a significant positive correlation with the Tmin and a slight negative correlation with the annual precipitation (Pcp). The glacier area revealed a strong negative correlation with the glacial lake area, Tmax, and the Tmin and a positive correlation with the annual precipitation. The results indicate that the glacial lakes in the region are expanding at the expense of their feeding glaciers under warming climate.