Spatio-temporal analysis of glacial lakes from 1990 to 2018 in the Kashmir Himalaya, India using geospatial technology

The glacial lakes were identified, delineated, and mapped to observe changes in spatial extent using multi-date/multi-sensor remote sensing data and adequately supplemented by field studies. Landsat imageries were used to delineate the spatial extent of glacial lakes for four time points i.e., 1990, 2000, 2010 and 2018. The total count of lakes as well as their spatial extent showed a discernible increase. The number has increased from 253 in 1990 to 322 in 2018 with a growth rate of 21.4 percent. The area has increased from 18.84 Km2 in 1990 to 22.11 Km2 in 2018 with a growth rate of 14.7 percent. The newly formed glacial lakes including supra glacial lakes were greater in number than the lakes that have disappeared over the study period. All glacial lakes are situated at an elevation of 2700 m asl and 4500 m asl.  More than 78 percent of lake expansion in the study region consists largely due to growth of existing glacial lakes. Through the area change analysis, our findings reveal that certain lakes show rapid expansion needing immediate monitoring and observation. In addition to climate variability, the presence of increasing quantities of light trapping particles could be possible causes for expanding of lakes in the Himalayas. Consequently, this study could play a significant role in devising a comprehensive risk assessment plan of potential GLOFs and develop a mechanism for continuous monitoring and management of lakes in the study region.