@article{Dubey2023,

title = {Mass Movement Hazard and Exposure in the Himalaya},

author = {Saket Dubey and Ashim Sattar and Manish Kumar Goyal and Simon Allen and Holger Frey and Umesh K. Haritashya and Christian Huggel},

url = {https://onlinelibrary.wiley.com/doi/full/10.1029/2022EF003253 https://onlinelibrary.wiley.com/doi/abs/10.1029/2022EF003253 https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2022EF003253},

doi = {10.1029/2022EF003253},

issn = {2328-4277},

year  = {2023},

date = {2023-01-01},

journal = {Earth's Future},

volume = {11},

issue = {9},

pages = {e2022EF003253},

publisher = {John Wiley & Sons, Ltd},

abstract = {Himalaya is experiencing frequent catastrophic mass movement events such as avalanches and landslides, causing loss of human lives and infrastructure. Millions of people reside in critical zones potentially exposed to such catastrophes. Despite this, a comprehensive assessment of mass movement exposure is lacking at a regional scale. Here, we developed a novel method of determining mass movement trajectories and applied it to the Himalayan Mountain ranges for the first time to quantify the exposure of infrastructure, waterways, roadways, and population in six mountain ranges, including Hindu Kush, Karakoram, western Himalaya, eastern Himalaya, central Himalaya, and Hengduan Shan. Our results reveal that the exposure of buildings and roadways to mass movements is highest in Karakoram, whereas central Himalaya has the highest exposed waterways. The hotspots of exposed roadways are concentrated in Nepal, the North Indian states of Uttarakhand, Himachal Pradesh, the Union Territory of Ladakh, and China's Sichuan Province. Our analysis shows that the population in the central Himalaya is currently at the highest exposure to mass movement impacts. Projected future populations based on Shared Socio-economic and Representative Concentration Pathways suggest that changing settlement patterns and emission scenarios will significantly influence the potential impact of these events on the human population. Assessment of anticipated secondary hazards (glacial lake outburst floods) shows an increase in probable headward impacts of mass movements on glacial lakes in the future. Our findings will support researchers, policymakers, stakeholders, and local governments in identifying critical areas that require detailed investigation for risk reduction and mitigation.},

keywords = {avalanche, Exposure, future hazard, Himalaya, landslides, mass movement},

pubstate = {published},

tppubtype = {article}

}

@article{Sattar2021,

title = {Future Glacial Lake Outburst Flood (GLOF) hazard of the South Lhonak Lake, Sikkim Himalaya},

author = {Ashim Sattar and Ajanta Goswami and Anil. V. Kulkarni and Adam Emmer and Umesh K. Haritashya and Simon Allen and Holger Frey and Christian Huggel},

url = {https://linkinghub.elsevier.com/retrieve/pii/S0169555X21001914},

doi = {10.1016/j.geomorph.2021.107783},

issn = {0169555X},

year  = {2021},

date = {2021-09-01},

journal = {Geomorphology},

volume = {388},

pages = {107783},

publisher = {Elsevier},

abstract = {The Teesta basin in Sikkim Himalaya hosts numerous glacial lakes in the high altitude glacierized region, including one of the largest and the fastest-growing South Lhonak Lake. While these lakes are mainly located in remote and unsettled mountain valleys, far-reaching glacial lake outburst floods (GLOFs) may claim lives and damage assets up to tens of kilometers downstream. Therefore, evaluating GLOF hazard associated with current and potential future glacier-retreat-driven changes is of high importance. In this work, we assess the future GLOF hazard of the South Lhonak Lake by integrating glacier and hydrodynamic modeling to calculate the lake's future volume and hydraulic GLOF characteristics and impacts along the valley. We identify the increased susceptibility of the lake to potential avalanche impacts as the lake grows in the future. Here we model six avalanche scenarios of varying magnitudes to evaluate the impact-wave generated in the lake and overtopping flow at the dam. Avalanche simulations indicate that the frontal moraine is susceptible to overtopping. The overtopping flow hydraulics is evaluated along the channel assuming no erosion of the moraine. Further, we consider three lake-breach scenarios to model GLOFs originating from the lake, flow propagation, and its downstream impacts. The uncertainty in the breach parameters including breach width and time of failure are calculated to estimate the upper and the lower hydraulic limits of potential future GLOF events. Further, the uncertainty in the flow hydraulics was evaluated using dynamic flood routing of six GLOFs that originate from the lake. Hydrodynamic GLOF modeling resulted in a predicted peak discharge of 4311 m3s−1, 8000 m3s−1, and 12,487 m3s−1 for breach depths of 20 m, 30 m, and 40 m respectively. The large-potential scenario suggests that maximum flow depth and flow velocity at Chungthang, a town proximally located to a major hydropower station built-in 2015, could reach up to 25–30 m and 6–9 m s−1, respectively. Mapping infrastructure exposed to GLOFs in the Teesta valley shows that many settlements and assets located along the river channel at Chungthang are potentially exposed to future GLOFs, indicating the need to conduct a full environmental impact assessment and potentially undertake GLOF risk mitigation measures.},

keywords = {Glacial lake outburst flood, Hazard, Himalaya, Risk, South Lhonak, Uncertainty},

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}

}