Glacial Lake Area Change and Potential Outburst Flood Hazard Assessment in the Bhutan Himalaya

作者：Sonam Rinzin, Guoqing Zhang, Sonam Wangchuk · 发表于：Frontiers in Earth Science · 年份：2021 · DOI：10.3389/feart.2021.775195 · 被引用次数：47 · 研究领域：Cryospheric studies and observations、Climate change and permafrost、Arctic and Antarctic ice dynamics

Against the background of climate change-induced glacier melting, numerous glacial lakes are formed across high mountain areas worldwide. Existing glacial lake inventories, chiefly created using Landsat satellite imagery, mainly relate to 1990 onwards and relatively long (decadal) temporal scales. Moreover, there is a lack of robust information on the expansion and the GLOF hazard status of glacial lakes in the Bhutan Himalaya. We mapped Bhutanese glacial lakes from the 1960s to 2020, and used these data to determine their distribution patterns, expansion behavior, and GLOF hazard status. 2,187 glacial lakes (corresponding to 130.19 ± 2.09 km 2 ) were mapped from high spatial resolution (1.82–7.62 m), Corona KH-4 images from the 1960s. Using the Sentinel-2 (10 m) and Sentinel-1 (20 m × 22 m), we mapped 2,553 (151.81 ± 7.76 km 2 ), 2,566 (152.64 ± 7.83 km 2 ), 2,572 (153.94 ± 7.83 km 2 ), 2,569 (153.97 ± 7.79 km 2 ) and 2,574 (156.63 ± 7.95 km 2 ) glacial lakes in 2016, 2017, 2018, 2019 and 2020, respectively. The glacier-fed lakes were mainly present in the Phochu (22.63%) and the Kurichu (20.66%) basins. A total of 157 glacier-fed lakes have changed into non-glacier-fed lakes over the 60 years of lake evolution. Glacier-connected lakes (which constitutes 42.25% of the total glacier-fed lake) area growth accounted for 75.4% of the total expansion, reaffirming the dominant role of glacier-melt water in expanding glacial lakes. Between 2016 and 2020, 19 (4.82 km 2 ) new glacial...