Regional morphodynamics of supraglacial lakes in the Everest Himalaya

Reduction of ice masses concerning global warming is significantly changing geomorphology in high mountains. 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 km²/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 new cluster 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 long-term) changes, lake density, and stability index were estimated and mapped. Finally, we concluded that new lake formations at higher elevation were 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.