Simulation of collapse process of ice-rich slope: A case of 2016 Giant Aru Glacier Collapse in Tibet, China

With climate change, high-altitude areas have been frequently observed with rising temperature and humidity levels, causing an increased likelihood of collapse of ice-rich slopes and threatening downstream human settlements and infrastructural assets. For example, two giant glaciers collapsed in 2016 in the Aru Range, Tibet, China, killing nine herders. Thus, developing numerical methodologies for stability analysis and reproducing the collapse and subsequent movement of landslide debris is imperative for proactively managing disaster risks. This study focuses on the two collapse events within the Aru Range, to numerically analyze the pre-collapse stability of the slopes and their movement processes after collapse. Compared with previous research, this study considers the impact of various environmental factors on the temperature and stability of the two Aru glaciers, especially the heat flux caused by subglacial seepage and geothermal activity. In addition to proving similar stability between the two slopes before the collapse and simulating the positions of headwalls after collapse, this study demonstrates the need of selecting the slope region for simulation, and clarifies the influence of subglacial water flow on the positions of headwalls. Finally, this study reproduces the transport distance of the sliding body and simulates the tsunami caused by the Aru glacial debris rushing into Aru Co Lake. An effective friction coefficient of 0.10–0.11 between the glacier debris and the terrain is proposed. This provides a reference for stability analyses and collapse consequence predictions of ice-rich slopes, aiding in developing strategies for hazard mitigation.