Spatiotemporal dynamics of glacial lakes (1990–2018) in the Kashmir Himalayas, India using Remote Sensing and GIS

Abstract

This study is perhaps the first attempt to use satellite data (1990–2018) to analyze spatiotemporal changes in glacial lakes over the Kashmir Himalayas supplemented by field studies. Landsat images were used to delineate the spatial extent of glacial lakes at 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 increased from 253 in 1990 to 324 in 2018, with a growth rate of 21.4%. The area has increased from 18.84 ± 0.1 km2 in 1990 to 22.13 ± 0.12 km2 in 2018 with a growth rate of 14.7%. The newly formed glacial lakes, including supraglacial lakes, were greater in number than the lakes that disappeared over the study period. All glacial lakes are situated at elevations of 2700 m asl and 4500 m asl. More than 78% of lake expansion in the study region is largely due to the growth of existing glacial lakes. Through area change analysis, our findings reveal that certain lakes show rapid expansion needing immediate monitoring and observation. The analysis of the meteorological variables reveals that minimum and maximum temperatures in the Jhelum basin have shown an increasing trend. Tmax showed an increase of 1.25 °C, whereas Tmin increased to 0.7 °C from 1980 to 2020. On the other hand, precipitation has shown a decreasing trend, which can be attributed to one of the major causes of glacier recession and the expansion of glacial lakes in the Upper Jhelum basin. Consequently, this study could play a significant role in devising a comprehensive risk assessment plan for potential Glacial Lake Outburst Floods (GLOFs) and developing a mechanism for continuous monitoring and management of lakes in the study region.

Glacial Lake Outburst Flood Hazard and Risk Assessment of Gangabal Lake in the Upper Jhelum Basin of Kashmir Himalaya Using Geospatial Technology and Hydrodynamic Modeling

“…GLOFs have become a severe threat in recent decades as a result of increased human settlements, anthropogenic activities, and unplanned infrastructural development in the fragile high alpine environment, which were not previously inhabited [40,46]. The Himalayan region is home to around 200 potentially hazardous glacial lakes and has witnessed 40 GLOF events in the past forty years [32,47].…”

“…Such robust techniques have been effectively used worldwide to monitor and assess glaciers, glacial lakes, and associated hazards. The GIS and RS-based tools and techniques reasonably allow rapid investigation of huge glaciated terrains and are therefore considered suitable for glacial lake and GLOF studies [40].…”

“…The changing precipitation regimes and increasing temperatures over the Indian Himalayan region are major concerns for the region's snow cover and glacier health [10]. The temperatures in the Jhelum basin, where Gangabal lake and its feeding glacier are located, have shown a significant increasing trend and decreasing precipitation trend [84,165,166], while glaciers, on the other hand, are rapidly retreating [41,84,166], and glacial lakes are expanding, and their frequency is increasing [39][40][41]. The warming temperatures and, thereby, rapid glacier melting in the area may result in sudden glacial lake outburst events, enhancing the GLOF susceptibility of the region.…”

“…Earlier, glacial lake studies in the former state of Jammu and Kashmir were carried out at different levels, for example, at the international level (glacial lake inventory of HMA) by Ives et al [32], Wang et al [33], and Chen et al [34]; at the national level by the Central Water Commission [35], National Remote Sensing Center Hyderabad [36], Ives et al [32], Fujita et al [37], and Worni et al [38]; and at the basin level by Dar et al [39] and Ahmed et al [40,41]. The Potentially Dangerous Glacial Lakes (PDGLs) in the area have been identified by seven previous studies.…”