A geospatial modelling for glacial lake outburst floods susceptibility analysis in the central Himalayas

ABSTRACT Glacial lakes have increased throughout a significant portion of the Himalayan region, and hence the present study focuses on a geospatial modelling approach for analysing the susceptibility to glacial lake outburst flood (GLOF) in the central Himalayan region. Multitemporal satellite imageries such as Landsat-TM and Sentinel-2 were taken. The hydrodynamic compatibility tool HEC-RAS 5.0 was used for GLOF prediction, and the lake volume and surface area were calculated using established empirical equations. The breach fails and flood flow were approximated, and arising uncertainties were analysed with three outburst scenarios. The number of lakes and their sizes have significantly increased according to the findings of the study. Of these, the Vasundhara Lake (VL), which is located at 4,676 m above the sea level, is assigned to the hazardous category for more examination. It has been found that the lake's area expanded over the past three decades (i.e. 1994–2020), rising from 0.15 to 0.29 km2. The study demonstrates that, in the worst-case situation, infrastructure along riverbanks may be susceptible to harm. The study provides information on the potential effects of GLOF events in the study region that might be used in early warning systems and water resource management plans.