Abstract

Glacial Lake Outburst Floods (GLOFs) are a recurring hazard in the Himalayas, posing significant threat to downstream communities. The North Sikkim district of India, comprising the upper reaches of the Teesta River in the Eastern Himalayas, has experienced past GLOF events. The identification of lakes susceptible to this phenomenon is therefore paramount. Using multi-temporal satellite images, this study tracks lake growth in the region, revealing that 203 new lakes had developed herein during the observation period (2000–2018). Of these, 82 lakes had formed during 2011–2018 alone; indicating marked glacial retreat and consequent lake area growth, alongside a rising temperature trend. Using various weighted geometric and geomorphic parameters, the 36 most hazardous lakes were identified, from which the 10 lakes posing the greatest GLOF threat were discerned. These lakes are mostly situated along the main snowline and Great Himalayan water-divide in the north-eastern part of Sikkim and should be monitored continuously.

摘要

冰川湖溃决洪水 (GLOF) 是喜马拉雅山脉经常发生的灾害，对下游社区构成重大威胁。印度的北锡金地区，包括东喜马拉雅山脉的提斯塔河上游，经历了过去的 GLOF 事件。因此，识别易受这种现象影响的湖泊至关重要。本研究使用多时相卫星图像跟踪该地区湖泊的生长情况，揭示在观测期间（2000-2018 年），这里已形成 203 个新湖泊。其中，仅在 2011-2018 年间就形成了 82 个湖泊；表明明显的冰川退缩和随之而来的湖泊面积增加，以及温度上升的趋势。使用各种加权几何和地貌参数，确定了 36 个最危险的湖泊，从中辨别出对 GLOF 构成最大威胁的 10 个湖泊。这些湖泊大多位于锡金东北部的主要雪线和大喜马拉雅分水岭沿线，应持续监测。