Field Assessment of Tam Pokhari Glacial Lake Outburst Flood in Khumbu Region, Nepal

Abstract

The Tam Pokhari glacial lake outburst flood (GLOF) in the Mount Everest region of Nepal is described pri-marily based on field observations by a survey team studying GLOF transmission areas and flood impact along the Inkhu River. An estimated accumulation of 18 billion cubic meters of water was suddenly released down the Inkhu River when a Tam Pokhari glacial lake moraine dam was breached. Field data suggests that the downstream flow consisted of massive sediment erosion and deposition resulting from bed slope changes and flow width and that river channel morphology was dramatically changed by this GLOF. As a consequence, the characteristics of GLOF changed drastically in downstream areas, resulting in infras-tructures damage. In addition, the GLOF created nu-merous debris fans now occupied by settlements, especially tourism-based industries.