Suchergebnisse

Abstract. Glacial lake outburst floods (GLOFs) are a major concern throughout High Mountain Asia, where societal impacts can extend far downstream. This is
particularly true for transboundary Himalayan basins, where risks are expected to further increase as new lakes develop. Given the need for
anticipatory approaches to disaster risk reduction, this study aims to demonstrate how the threat from a future lake can be feasibly assessed
alongside that of worst-case scenarios from current lakes, as well as how this information is relevant for disaster risk management. We have focused on two previously identified dangerous lakes (Galongco and Jialongco), comparing the timing and magnitude of simulated worst-case outburst events from these lakes both in the Tibetan town of Nyalam and downstream at the border with Nepal. In addition, a future scenario has been assessed, whereby an avalanche-triggered GLOF was simulated for a potential large new lake forming upstream of Nyalam. Results show that large (>20×106 m3) rock and/or ice avalanches could generate GLOF discharges at the border with Nepal that are more than 15 times larger than what has been observed previously or anticipated based on more gradual breach simulations. For all assessed lakes, warning times in Nyalam would be only 5–11 min and 30 min at the border. Recent remedial measures undertaken to lower the water level at Jialongco would have little influence on downstream impacts resulting from a very large-magnitude GLOF, particularly in Nyalam where there has been significant development of infrastructure directly within the high-intensity flood zone. Based on these findings, a comprehensive approach to disaster risk management is called for, combining early warning systems with effective land use zoning and programmes to build local response capacities. Such approaches would address the current drivers of GLOF risk in the basin while remaining robust in the face of worst-case, catastrophic outburst events that become more likely under a warming climate.

Abstract. Glacial lake outburst floods (GLOFs) are among the most
concerning consequences of retreating glaciers in mountain ranges worldwide.
GLOFs have attracted significant attention amongst scientists and
practitioners in the past 2 decades, with particular interest in the
physical drivers and mechanisms of GLOF hazard and in socioeconomic and other
human-related developments that affect vulnerabilities to GLOF events. This
increased research focus on GLOFs is reflected in the gradually increasing
number of papers published annually. This study offers an overview of recent
GLOF research by analysing 594 peer-reviewed GLOF studies published between
2017 and 2021 (Web of Science and Scopus databases), reviewing the content and
geographical focus as well as other characteristics of GLOF studies. This
review is complemented with perspectives from the first GLOF conference (7–9
July 2021, online) where a global GLOF research community of major
mountain regions gathered to discuss the current state of the art of
integrated GLOF research. Therefore, representatives from 17 countries
identified and elaborated trends and challenges and proposed possible ways
forward to navigate future GLOF research, in four thematic areas: (i) understanding GLOFs – timing and processes; (ii) modelling GLOFs and GLOF
process chains; (iii) GLOF risk management, prevention and warning; and (iv) human dimensions of GLOFs and GLOF attribution to climate change.