Optical remote sensing monitoring and dynamic analysis of ice avalanche hazards in Midui glacier of Southeast Tibet

Under the background of global warming, glaciers instability in Southeast Tibet, where glaciers are widely distributed, are prominent. Based on the medium-high resolution multi-source satellite data, such as Gaofen-1(hereinafter referred to as "GF-1"), Gaofen-2(hereinafter referred to as "GF-2"), and Unmanned Aerial Vehicle(hereinafter referred to as "UAV"), aerial photography, the basic characteristics and changes in ice avalanche hazards in Midui glacier are studied. We summarize the optical remote sensing characteristics of Midui glacier, analyze the dynamic change trend of ice fissures and glacial lake area since 2001, and discuss the possibility of ice avalanche and break of glacial lake in Midui glacier combined with regional geological environment background. The study results showed 6 potential ice avalanches, 15 glacial lakes, 3 moraines, and 21 collapses in Miduiqu. Since 2001, the scale of potential ice fissures and the area of glacial lakes have increased, and they accelerated in 2014 and 2017, respectively. As a result of the steep-slow-steep ladder-like terrain, a large number of ice fissures at the end of the glacier, numerous loose collapse deposits on both sides of the channel, the strong tectonic activity in Jiali fault zone, and other factors, Midui glacier is likely to destabilize and cause ice avalanche, forming a disaster chain of ice avalanche-glacial lake outburst-debris flow, which directly threatens the Midui village, Midui glacier tourism distribution center, and National Highway 318. If the debris flow moves to the Midui gully mouth and blocks the Parlung Zangbo River, it will form a large disaster chain. Based on the research results, the movement possibility of Midui glacier should be closely monitored for a long time to provide basic information for ice avalanche disaster research and prevention of such events in Southeast Tibet.