The effect of climate change on alpine mountain hazards chain: A case study in Tianmo Ravine, Tibet, China

Abstract

Mountain hazards behave a relatively high incidence under regional climate change condition. This compound hazard is often initiated by environment and climate change. A combination of glacial melting and rainfall-induced compound disaster event happened in Tianmo Ravine, Bomi County, Tibet, China on 25 July and 4 September 2010, separately. The debris flow with 450,000 m 3 volume transported along gully and then flushed into Parlung Tsangpo River in the deposition zone, resulting in a destruction of 400 m length section of the G318 highway from Bomi County to Lhasa. A detailed interpretation of this disaster was conducted using unique and high-resolution images obtained through remote sensing. The source material, terrain condition, and climate condition were analyzed to have a comprehensive understanding of environmental background for hazard initiation. It is concluded that the occurring of this disaster event is the comprehensive result of multiple factors led by the climate change. Abundant antecedent precipitation, melting of the glacier, and the instability of soil caused by wetting-drying cycles, led to the occurrence of the Tianmo Ravine disaster. Based on taking various factors into account synthetically, the comprehensive hazards pattern is named using “Mountain hazards pattern in glacial alpine region under climate change (MH-GA-CC)”. The climate is the special factor feature that should be taken into account emphatically. The study here provides a scientific base pattern for the future risk assessment of glacial alpine areas under regional climate change background.