Recent and future EVOlution of GLacial Lakes in China (EVOGLAC): Spatio-temporal diversity and hazard potential


The disappearance of mountain glaciers and expansion of glacial lakes are  amongst the most recognizable and dynamic impacts of global warming. Such new  lakes bring opportunities (e.g., hydropower) but also pose significant  threats, due to the increasing potential for catastrophic Glacial Lake Outburst Floods (GLOFs). This threat is most pronounced across high mountain  Asia, where communities, transportation networks, and other vital  infrastructure are exposed. This is particularly true for China, where many  potentially dangerous lakes have been documented, and significant growth of  these lakes has been noted over recent decades. In view of projected warming  over the 21st century and continued retreat of glaciers, scientific attention  has recently shifted beyond monitoring and assessment of the existing GLOF  threat towards the anticipation of where new, potentially problematic lakes  will form in the future. Such lakes will most likely develop in bedrock  depressions or overdeepenings in the exposed glacier bed, and as such, methods  have been developed to model bed topography and thereby identify where these  new lakes will form. However, a key limitation remains that timing of the  emergence and future evolution of glacial lakes is generally unconstrained for  data-scarce mountain regions. This represents a major scientific challenge, as  local climatological, geomorphological, and topographic conditions will lead  to significant diversity in lake evolution. In addition, integrated approaches  are yet to be developed which consider the full range of triggering processes  that contribute to GLOF hazard both now, and in the future. Highly transient  factors include the stability of surrounding ice and rock walls, the thawing  of ice-cored moraine dams, and changes in heavy precipitation, snowmelt and  faster runoff that may be expected in some deglaciated catchments.

The overall aim of the proposed study is to develop and implement a  comprehensive methodological approach to investigate the recent and future  evolution of glacial lakes and their related hazard potential in different  climatological, geomorphological, and topographic settings. This will lead to  improved understanding and prediction of lake formation, change in GLOF  triggering processes, and change in hazard in downstream areas, as glaciers  continue to retreat over the 21st century and beyond. The research methodology  is centred on 7 work packages which bring together the complementary strengths of the partner institutions in the fields of remote sensing based analyses of the cryosphere, GIS-based modelling, and GLOF hazard assessment. Within three contrasting study regions in Tibet, reconstruction of the recent (since ca.1970) evolution of glacier thinning, retreat, and associated lake development will provide the basis for catchment-scale modelling of future changes. The integrated modelling approach will consider not only the expansion of existing lakes, but also the formation of new lakes in the exposed bed topography, and will investigate the corresponding increase in GLOF potential as key transient triggering processes evolve in a warmer climate. For selected critical lakes, both now, and in the future, complete lake outburst and flow modelling will be undertaken, providing a quantitative basis for assessing the change in downstream hazard.

The methodological approach will be optimised for outscaling to larger regions, recognising the urgent need for robust scientific information to support adaptation planning in response to the rapidly evolving GLOF threat across high mountain Asia. The exchange of knowledge between Swiss and Chinese partners will ensure that local scientists are best positioned to lead ongoing monitoring programs and further research activities in the region. 

Principle Investigator:Yao Tandong

Project duration:2017.01-2020.12