A robust glacial lake outburst susceptibility assessment approach validated by GLOF event in 2020 in the Nidu Zangbo Basin, Tibetan Plateau

As reports on glacial lake outburst floods (GLOFs) have increased with global warming, a robust GLOF susceptibility assessment approach is critical for disaster prevention and damage reduction. A robust GLOF susceptibility assessment approach, using the Analytic Hierarchy Process (AHP) to assess the potential hazard grades of glacial lakes combined with data from a digital elevation model (DEM), glaciers, remote sensing images, and field investigations, was constructed and applied in the Nidu Zangbo Basin in Nagqu, Tibetan Plateau. From 1988 to 2016, the total number and area of glacial lakes increased in this basin. There were 71 glacial lakes in the Nidu Zangbo Basin with a total area of 3.42 km2 in 2016, among which 14 lakes, accounting for an area>0.05 km2, were considered to be potentially dangerous glacial lakes (PDGLs) in this study. At the end of 2017, the proposed approach identified 6 of 14 PDGLs as high potentially hazardous, among which Jinwucuo, with the highest hazardous score, occurred GLOF event on June 26, 2020, which proves the robustness of the approach. Thus, the GOLF susceptibility in the Nidu Zangbo Basin was suggested to be evaluated regularly with the approach and update monitoring data and remote sensing images. The study provides valuable clues to assess the GLOF susceptibilities in High Mountain Asia (HMA).