Climate Change Induced Glacier Retreat and Risk Management: Glacial Lake Outburst Floods (GLOFs) in the Apolobamba Mountain Range, Bolivia

Abstract

Due to global warming, tropical glaciers in the Bolivian Andes have lost about half of their volume and surface area since 1975. Throughout the Apolobamba mountain range, the retreat of glaciers has resulted in the formation of small and medium-sized lakes on the glacier terminus. Many of the glacial lakes are contained only by loose moraine debris: thus they can pose a significant threat to human settlements and infrastructure downstream. Considering the fact that the Cordillera de Apolobamba holds the largest continuous glaciated area in Bolivia, which measured 220 km² in the 1980s, there is a legitimate concern regarding the dangers that might affect this mountain region. Yet there is no documentation available on glacial lakes in the Apolobamba mountain range; indeed there is little awareness of the related risks. Only recently has glacial retreat, and climate change impacts in general, been given some importance in the planning and management of the Apolobamba National Protected Area for Integrated Management, thereby opening a discussion on natural hazard threats and the development of adaptation strategies with the objective of minimising risks for human populations and local infrastructure. This paper presents documentation of glacier retreat and the forming of glacial lakes in the Cordillera of Apolobamba over the last 35 years. In addition, the risk potential of glacial lake outburst floods and the risk awareness of the local population will be analysed in relation to park management options, and ideas outlined for more detailed studies of glacial lake outburst floods in Bolivia.