datasheet1_Evaluation of Glacial Lake Outburst Flood Susceptibility Using Multi-Criteria Assessment Framework in Mahalangur Himalaya.pdf

Ongoing recession of glaciers in the Himalaya in response to global climate change has far-reaching impacts on the formation and expansion of glacial lakes. The subsequent glacial lake outburst floods (GLOFs) are a significant threat to lives and livelihoods as they can cause catastrophic damage up to hundreds of kilometres downstream. Previous studies have reported the rapid expansion of glacial lakes and several notable destructive past GLOF events in the Mahalangur Himalaya, suggesting a necessity of timely and updated GLOF susceptibility assessment. Here, an updated inventory of glacial lakes across the Mahalangur Himalaya is developed based on 10-m Sentinel-2 satellite data from 2018. Additionally, the GLOF susceptibilities of glacial lakes (≥0.045 km2) are evaluated using a multi-criteria-based assessment framework where six key factors are selected and analyzed. Weight for each factor was assigned from the analytical hierarchy process. Glacial lakes are classified into very low, low, medium, high, and very high GLOF susceptibility classes depending upon their susceptibility index based on analysis of three historical GLOF events in the study area. The result shows the existence of 345 glacial lakes (>0.001 km2) with a total area of 18.80 ± 1.35 km2 across the region in 2018. Furthermore, out of the 64 glacial lakes (≥0.045 km2) assessed, seven were identified with very high GLOF susceptibility. We underline that pronounced glacier-lake interaction will likely increase the GLOF susceptibility. Regular monitoring and more detailed fieldworks for these highly susceptible glacial lakes are necessary. This will benefit in early warning and disaster risk reduction of downstream communities.

喜马拉雅山脉冰川持续退缩，作为全球气候变化之响应，其影响深远，不仅对冰川湖的形成与扩张造成影响，而且其后续的冰川湖溃决洪水（GLOFs）对生命和生计构成重大威胁，可能导致数百公里下游的灾难性破坏。先前的研究报告了玛哈朗格尔喜马拉雅山脉冰川湖的迅速扩张以及数起显著的毁灭性过去GLOF事件，这表明及时且更新的GLOF易损性评估的必要性。在此，基于2018年的10米分辨率Sentinel-2卫星数据，构建了玛哈朗格尔喜马拉雅山脉冰川湖的更新清单。此外，利用基于多标准的评估框架对冰川湖的GLOF易损性（≥0.045平方公里）进行了评估，其中选定了六个关键因素进行分析，并从层次分析法中分配了每个因素的权重。根据对研究区域内三个历史GLOF事件的敏感性分析，将冰川湖分为极低、低、中、高和极高GLOF易损性等级。结果显示，2018年该区域存在345个冰川湖（>0.001平方公里），总面积为18.80 ± 1.35平方公里。此外，在评估的64个冰川湖（≥0.045平方公里）中，有七个被确定为极高GLOF易损性。我们强调，冰川与湖泊之间的显著相互作用可能会增加GLOF易损性。对这些高度易损的冰川湖进行定期监测和更详细的实地工作是必要的，这将有助于下游社区的早期预警和灾害风险降低。