Flooding (or breaching) of inter-connected proglacial lakes by cascading overflow in the arid region of Western Mongolia (Mt. Tsambagarav, Mongolian Altai)

초록

This study investigates the glacial lake outburst flood (GLOF) hazards in the Tsambagarav mountain range in Western Mongolia, focusing on the Khukhnuruu Valley and its interconnected proglacial lakes. Over the last 30 years, significant glacier retreats, driven by rising temperatures and changing precipitation patterns, have led to the formation and expansion of several proglacial lakes. Fieldwork combined with satellite data and meteorological analysis was used to assess the dynamics of glacier and lake area changes, with particular focus on the flood events of July 2021. The research reveals a substantial reduction in glacier area, particularly in the Khukhnuruu E complex, where glacier area decreased by 19.3%. The study highlights the influence of increasing temperatures and summer precipitation, which have accelerated ice melt, contributing to the expansion and eventual breaching of lakes. Additionally, lake area changes were influenced by the steepness of the terrain, with steeper slopes exacerbating peak discharge during floods. Of the studied seven lakes (Lake 1 to Lake 7), Lake 1 experienced the most dramatic reduction, with a decrease in area by 73.51% and volume by 84.84%, followed by Lake 7. This study underscores the region's vulnerability to climate-induced hazards and stresses the need for a comprehensive early warning system and disaster preparedness measures to mitigate future risks.

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