Regional morphodynamics of supraglacial lakes in the Everest Himalaya

Reduction of ice masses concerning globalwarming is significantly changing geomorphology in highmountains. Formation of supraglacial lakes is one of such essential indications. Therefore, in the present study, we attempted to understand regional morphodynamics of supraglacial lakes, distributed in 17 glaciers within the Everest Himalaya. An average of 0.08 km(2)/yr lake expansion rate was noticed during the studied year. Decadal (2010-2019) lake morphodynamic study using high resolution satellite images revealed that only 161 out of total 2424 lakes were static, and mostly concentrated at the lower part of the ablation area with an alarming rate of surface area increase. We also found appearance of newcluster of lakes at higher elevations. We collected here statistical evidences of regional morphodynamics and key controlling factors to stabilize lakes. The parameters, viz., spatio-temporal distribution of lakes, their domain wise variation, multi-temporal (Seasonal to longterm) changes, lake density, and stability index were estimated and mapped. Finally, we concluded that new lake formations at higher elevationwere triggered by gradual increase in temperature, decrease in glacier surface velocity, slope and ice thickness. The feature selection techniques indicated ice thickness as prior controlling factor followed by the surface velocity and slope to stabilize lakes at the lower part of ablation. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

The reduction of ice masses in high mountains due to global warming is leading to significant changes in geomorphology, with the formation of supraglacial lakes being a key indicator. A study on the regional morphodynamics of supraglacial lakes in the Everest Himalaya revealed an average lake expansion rate of 0.08 km(2)/yr and the appearance of new lake clusters at higher elevations. Factors such as temperature increase, glacier surface velocity decrease, slope, and ice thickness were identified as triggers for the formation and stability of lakes.