Simulation and Evaluation of Glacier Lake Outburst Floods for Chenab River Basin
The glaciers in Himalayan region have shown remarkable changes due to climate change in recent times, which resulted in melting of many big glaciers leading to formation of several glacial lakes. The water storage in these lakes increases due to the melting of ice and snow, which causes sudden discharge of water and the debris from these lakes in large volume. The sudden discharge of large volumes of water as well as debris from these lakes, is the potential cause of Glacial Lake Outburst Floods (GLOFs) in valleys downstream. In this study, the Chenab river basin, located in the Western Himalaya region of India, is chosen for the estimation of GLOF. Among the various lakes of the basin, two lakes are studied for simulation and assessment of GLOF. The HEC-RAS software is used for the study of GLOF for the aforesaid lakes. The flood peaks at GLOF site from lake 1 and lake 2 are 10,917 m3/s and 17,971 m3/s, respectively. The flood peaks at outlet are 9,717 m3/s, 7,348 m3/s and flood peak travel time from lake site to outlet at a distance of 12 km and 82 km are 1 hour 10 minutes and 5 hour 20 minutes, respectively. These details are very useful for planners and designers to minimize and mitigate the effects of GLOF.
Keywords: GLOF, Outburst hydrograph, Dam break modeling, River cross-sections, Breach width