| 摘要: |
| 位于青藏高原西部的新藏公路（G219）是连接新疆和西藏的重要交通线，沿线途经喜马拉雅山、冈底斯山、喀喇昆仑山和西昆仑山等众多山脉，这些区域冰湖广泛发育，公路易受潜在冰湖溃决洪水（Glacial Lake Outburst Floods, GLOFs）威胁。本文基于Landsat ETM+和Sentinel-2 MSI遥感影像，采用NDWI方法与人工目视修订相结合方式提取2000年和2022年新藏公路沿线流域冰湖边界数据，并对该区域冰湖时空演变特征、GLOF危险性及潜在受影响路段进行了分析和评估。结果表明：（1）2022年新藏公路沿线流域共有冰湖1412个，总面积141.13 km2；2000—2022年期间，研究区内面积≥0.01 km2的冰湖数量和面积均呈增长趋势，分别增加了98个（7.46%）和2.16 km2（1.56%）；海拔4500 m以下的冰湖数量和面积相对稳定，而海拔5000 m以上地区的冰湖数量和面积增加相对迅速。（2）对研究区内面积>0.1 km2的70个冰碛湖进行GLOF危险性评估发现，具有极高、高、中和低危险性的冰碛湖分别有13个、24个、13个和20个；新藏公路共有10处易受危险冰湖溃决洪水影响的路段，特别是R1（K514+210~K514+770）、R2（K793+190~K802+250）、R4（K1286+690~K1287+880）、R8（K1684+900~K1685+380）和R9（K1786+110~K1801+700），这些路段应加强上游冰湖动态监测并采取相应的防治措施。 |
| 关键词: 冰湖 冰湖溃决洪水 遥感 新藏公路 |
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| 基金项目:国家自然科学基金项目（42071089）和第三次新疆综合科学考察项目（2021xjkk0801）联合资助,国家自然科学基金项目（面上项目，重点项目，重大项目） |
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| Changes and GLOF hazard assessment of glacial lakes within the basins where the Xinjiang-Tibet Road passes |
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Chang Jiahao1, Yao Xiaojun1, Wang Yu2, Duan Hongyu1, Zhang Cong1, Zhang Yuan1, Liu Yidan1
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1.College of Geography and Environmental Science,Northwest Normal University;2.Sichuan Geological Big Data Center
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| Abstract: |
| The Xinjiang-Tibet Road (G219), located in the western part of the Tibetan Plateau, is an important transportation route connecting Xinjiang and Tibet. There are numerous mountains along the route, including the Himalayas, Gangdisê, Karakorum and Western Kunlun, where glacial lakes are widely developed and the road is susceptible to potential glacial lake outburst floods (GLOFs). Based on Landsat ETM+ and Sentinel-2 MSI images, a combination of the NDWI method and manual visual revision was employed to extract boundaries of glacial lakes within the basins where the Xinjiang-Tibet Road passes in 2000 and 2022. Furthermore, we analyzed the spatial and temporal evolution characteristics of glacial lakes in this region and assessed their GLOF hazards as well as potential affected road sections. The results showed that: (1) In 2022, there were a total of 1412 glacial lakes covering an area 141.13 km2 within these basins. From 2000 to 2022, both the number and area of glacial lakes with an area of ≥0.01 km2 showed an increasing trend, with an increase of 98 (7.46%) and 2.16 km2 (1.56%), respectively. The number and area of glacial lakes below an altitude of 4500 m remained relatively stable, while those above an altitude of 5000 m experienced rapid growth. (2) The GLOF hazard assessment of 70 moraine-dammed glacial lakes with an area of >0.1 km2 identified 13 very high, 24 high, 13 medium and 20 low cases. Moreover, ten sections along the Xinjiang-Tibet Road that were found susceptible to hazardous GLOFs, especially R1 (K514+210~K514+770), R2 (K793+190~K802+250), R4 (K1286+690~K1287+880), R8 (K1684+900~K1685+380) and R9 (K1786+110~K1801+700). The strengthening of glacial lake dynamic monitoring in upstream of these sections and implementation of corresponding control measures are highly recommended. |
| Key words: glacial lake glacial lake outburst floods hazard assessment remote sensing Xinjiang-Tibet Road |
