Variations of glacial lakes and glaciers in the Boshula mountain range, southeast Tibet, from the 1970s to 2009

Abstract

AbstarctCatastrophic floods originating from glacial lake outbursts have recently become one of the primary natural hazards in the southeastern Tibetan Plateau. Here we report observations of glacial lake expansions and glacier recessions in the Boshula mountain range, southeast Tibet, derived from multitemporal remote-sensing images and digital elevation models during the period from the 1970s to 2009. The area of glacial lakes has expanded from 10.96 ± 0.1 km2in the 1970s to 10.96±0.1km2in 2009. Specifically, the area of moraine-dammed lakes has increased by 26.8%. From the 1970s to 2009, the glacierized area in the Boshula mountain range shrank by 12.7% (21.2 km2). Increasing mean summer air temperature was the main cause for the glacier recession and lake expansion from the 1970s to 2001, while the combination of increased summer temperature and decreased summer precipitation led to accelerated glacier recession after 2001. Climate warming and ongoing deglaciation play important roles in the expansion of moraine-dammed lakes, calling for intensified monitoring to properly address the hazard potential in the study area.