@article{Vilca2021,

title = {The 2020 glacial lake outburst flood process chain at Lake Salkantaycocha (Cordillera Vilcabamba, Peru)},

author = {Oscar Vilca and Martin Mergili and Adam Emmer and Holger Frey and Christian Huggel},

url = {https://link.springer.com/10.1007/s10346-021-01670-0},

doi = {10.1007/s10346-021-01670-0},

issn = {1612-510X},

year  = {2021},

date = {2021-06-01},

journal = {Landslides},

volume = {18},

number = {6},

pages = {2211--2223},

abstract = {Glacial lakes represent a threat for the populations of the Andes and numerous disastrous glacial lake outburst floods (GLOFs) occurred as a result of sudden dam failures or dam overtoppings triggered by landslides such as rock/ice avalanches into the lake. This paper investigates a landslide-triggered GLOF process chain that occurred on February 23, 2020, in the Cordillera Vilcabamba in the Peruvian Andes. An initial slide at the SW slope of Nevado Salkantay evolved into a rock/ice avalanche. The frontal part of this avalanche impacted the moraine-dammed Lake Salkantaycocha, triggering a displacement wave which overtopped and surficially eroded the dam. Dam overtopping resulted in a far-reaching GLOF causing fatalities and people missing in the valley downstream. We analyze the situations before and after the event as well as the dynamics of the upper portion of the GLOF process chain, based on field investigations, remotely sensed data, meteorological data and a computer simulation with a two-phase flow model. Comparison of pre-and post-event field photographs helped us to estimate the initial landslide volume of 1-2 million m 3. Meteorological data suggest rainfall and/or melting/thawing processes as possible causes of the landslide. The simulation reveals that the landslide into the lake created a displacement wave of 27 m height. The GLOF peak discharge at the dam reached almost 10,000 m 3 /s. However, due to the high freeboard, less than 10% of the lake volume drained, and the lake level increased by 10-15 m, since the volume of landslide material deposited in the lake (roughly 1.3 million m 3) was much larger than the volume of released water (57,000 m 3 , according to the simulation). The model results show a good fit with the observations, including the travel time to the uppermost village. The findings of this study serve as a contribution to the understanding of landslide-triggered GLOFs in changing high-mountain regions. Keywords GLOF. High-mountain areas. Impact wave. Moraine-dammed lake. Process chain. Rock avalanche Introduction Continued retreat of glaciers often leads to the formation of glacial lakes, retained behind stable rock dams (i.e. occupying glacier overdeepenings) or dammed by potentially unstable moraine dams. Such lakes can drain suddenly, releasing large amounts of water that can result in complex and potentially catastrophic downstream process chains. Glacial lake outburst floods (GLOFs) have been the subject of numerous studies covering many mountain regions around the world (Hewitt 1982; Haeberli 1983; Rich-ardson and Reynolds},

keywords = {GLOF, High-mountain areas, Impact wave, Moraine-dammed lake, process chain, rock avalanche},

pubstate = {published},

tppubtype = {article}

}

@article{Allen2019,

title = {Potentially dangerous glacial lakes across the Tibetan Plateau revealed using a large-scale automated assessment approach},

author = {Simon Keith Allen and Guoqing Zhang and Weicai Wang and Tandong Yao and Tobias Bolch},

doi = {10.1016/j.scib.2019.03.011},

issn = {20959281},

year  = {2019},

date = {2019-04-01},

journal = {Science Bulletin},

volume = {64},

number = {7},

pages = {435--445},

publisher = {Elsevier B.V.},

abstract = {Glacial lake outburst floods (GLOFs) are a major concern in the Himalaya and on the Tibetan Plateau (TP), where several disasters occurring over the past century have caused significant loss of life and damage to infrastructure. This study responds directly to the needs of local authorities to provide guidance on the most dangerous glacial lakes across TP where local monitoring and other risk reduction strategies can subsequently be targeted. Specifically, the study aims to establish a first comprehensive prioritisation ranking of lake danger for TP, considering both the likelihood and possible magnitude of any outburst event (hazard), and the exposure of downstream communities. A composite inventory of 1,291 glacial lakes (textgreater0.1 km 2 ) was derived from recent remote sensing studies, and a fully automated and object assessment scheme was implemented using customised GIS tools. Based on four core determinates of GLOF hazard (lake size, watershed area, topographic potential for ice/rock avalanching, and dam steepness), the scheme accurately distinguishes the high to very high hazard level of 19 out of 20 lakes that have previously generated GLOFs. Notably, 16% of all glacial lakes threaten human settlements, with a hotspot of GLOF danger identified in the central Himalayan counties of Jilong, Nyalam, and Dingri, where the potential trans-boundary threat to communities located downstream in Nepal is also recognised. The results provide an important and object scientific basis for decision-making, and the methodological approach is ideally suited for replication across other mountainous regions where such first-order studies are lacking.},

keywords = {Danger, Exposure, GLOF, Hazard, Himalaya, Tibetan Plateau},

pubstate = {published},

tppubtype = {article}

}