气候变化领域集成服务门户(CCPortal): The 2020 glacial lake outburst flood at Jinwuco, Tibet: Causes, impacts, and implications for hazard and risk assessment

CCPortal

DOI	10.5194/tc-15-3159-2021
	The 2020 glacial lake outburst flood at Jinwuco, Tibet: Causes, impacts, and implications for hazard and risk assessment
	Zheng G.; Mergili M.; Emmer A.; Allen S.; Bao A.; Guo H.; Stoffel M.
发表日期	2021
ISSN	19940416
起始页码	3159
结束页码	3180
卷号	15 期号:7
英文摘要	We analyze and reconstruct a recent glacial lake outburst flood (GLOF) process chain on 26 June 2020, involving the moraine-dammed proglacial lake-Jinwuco (30.356° N, 93.631° E) in eastern Nyainqentanglha, Tibet, China. Satellite images reveal that from 1965 to 2020, the surface area of Jinwuco has expanded by 0.2 km2 (+56 %) to 0.56 km2 and subsequently decreased to 0.26 km2 (-54 %) after the GLOF. Estimates based on topographic reconstruction and sets of published empirical relationships indicate that the GLOF had a volume of 10 million cubic meters, an average breach time of 0.62 h, and an average peak discharge of 5602 m3/s at the dam. Based on pre- and post-event high-resolution satellite scenes, we identified a large debris landslide originating from western lateral moraine that was most likely triggered by extremely heavy, south-Asian-monsoon-associated rainfall in June 2020. We back-calculate part of the GLOF process chain, using the GIS-based open-source numerical simulation tool r.avaflow. Two scenarios are considered, assuming a debris-landslide-induced impact wave with overtopping and resulting retrogressive erosion of the moraine dam (Scenario A), as well as retrogressive erosion without a major impact wave (Scenario B). Both scenarios are in line with empirically derived ranges of peak discharge and breach time. The breaching process is characterized by a slower onset and a resulting delay in Scenario B compared to Scenario A. Comparison of the simulation results with field evidence points towards Scenario B, with a peak discharge of 4600 m3/s. There were no casualties from this GLOF, but it caused severe destruction of infrastructure (e.g., roads and bridges) and property losses in downstream areas. Given the clear role of continued glacial retreat in destabilizing the adjacent lateral moraine slopes and directly enabling the landslide to deposit into the expanding lake body, the GLOF process chain can be plausibly linked to anthropogenic climate change, while downstream consequences have been enhanced by the development of infrastructure on exposed flood plains. Such process chains could become more frequent under a warmer and wetter future climate, calling for comprehensive and forward-looking risk reduction planning. © 2021 Guoxiong Zheng et al.
英文关键词	cryosphere; flood; glacial lake; outburst; risk assessment; China; Qinghai-Xizang Plateau
语种	英语
来源期刊	Cryosphere
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/202459
作者单位	State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Ürümqi, 830011, China; Climatic Change Impacts and Risks in the Anthropocene (C-CIA), Institute for Environmental Sciences, University of Geneva, Geneva, 1205, Switzerland; University of Chinese Academy of Sciences, Beijing, 100049, China; Institute of Geography and Regional Science, University of Graz, Graz, 8010, Austria; Institute of Applied Geology, University of Natural Resources and Life Sciences (BOKU), Vienna, 1190, Austria; Department of Geography, University of Zurich, Zurich, 8057, Switzerland; China-Pakistan Joint Research Centre on Earth Sciences, CAS-HEC, Islamabad, 45320, Pakistan; School of Geography and Tourism, Qufu Normal University, Rizhao, 276800, China; Department of Earth Sciences, University of Geneva, Geneva, 1205, Switzerland; Department F.-A. Forel for Environmental and Aquatic Sciences, University of Geneva, Geneva, 1205, Switzerland
推荐引用方式 GB/T 7714	Zheng G.,Mergili M.,Emmer A.,et al. The 2020 glacial lake outburst flood at Jinwuco, Tibet: Causes, impacts, and implications for hazard and risk assessment[J],2021,15(7).
APA	Zheng G..,Mergili M..,Emmer A..,Allen S..,Bao A..,...&Stoffel M..(2021).The 2020 glacial lake outburst flood at Jinwuco, Tibet: Causes, impacts, and implications for hazard and risk assessment.Cryosphere,15(7).
MLA	Zheng G.,et al."The 2020 glacial lake outburst flood at Jinwuco, Tibet: Causes, impacts, and implications for hazard and risk assessment".Cryosphere 15.7(2021).