Evolution Patterns and Outburst Risk Evaluation of Luregou Glacial Lake in Northern Tibet

Abstract

Affected by global warming, glacial lake outburst events occur frequently on the Qinghai-Tibet Plateau. Glacial lake outburst is characterized by large scale, sudden occurrence, danger and difficulty in prevention and control. Based on the remote sensing interpretation and field investigation of 29 glacial lakes in Luregou basin in the upper reaches of Yigongzangbu basin, four periods in 1976, 1988, 2001 and 2013, the development characteristics, distribution patterns and types of changes in glacial lakes were deeply analyzed. Factors such as changes in glacial lake area, terminal moraine dam, ice avalanche and ice landslides, and glacial lake types were selected to initially construct a rapid rating method for glacial lake outburst risk. Using this method, 29 glacial lake outburst risks were evaluated in Luregou Basin, and the evaluation results showed that the risks were large, medium and small in 5, 6 and 18 places respectively. Furthermore, the outburst mechanism and disaster effect of Ranzeriacuo glacial lake on July 5, 2013 were analyzed in detail.