Modeling glacial lake outburst flood process chains in Sikkim Himalaya: Hazard assessment of two potentially dangerous lakes

2021 ◽  
Author(s):  
Ashim Sattar ◽  
Simon Allen ◽  
Holger Frey ◽  
Christian Huggel ◽  
Martin Mergili
Keyword(s):  
Risk Reduction ◽  
Land Use Planning ◽  
Early Warning Systems ◽  
Glacial Lake ◽  
Glacial Lakes ◽  
National Guidelines ◽  
Flow Process ◽  
Outburst Floods ◽  
Reduction Strategies ◽  
Risk Reduction Strategies

<p>The presence of large and rapidly growing glacial lakes along the Himalayan Arc makes glacial lake outburst floods (GLOFs) a serious mountain hazard. While glacial lakes are mainly located in remote and unsettled mountain valleys, far-reaching GLOFs may claim lives and damage assets tens of kilometers downstream. Evaluating GLOF hazard is therefore of high importance, considering current and potential future climate-driven changes of glaciers and glacial lakes. A major concern in the Northeastern Indian Himalayan state of Sikkim is the damage potential these flood events can cause to hydropower plants and local vulnerable communities. This is particularly true for outburst floods potentially originating from the two lakes in Sikkim that are considered hazardous: the South Lhonak Lake and the Shako Cho Lake. Both lakes have been recognized in previous studies, and by local and state authorities, as being high priority sites for further monitoring and potential risk reduction measures. Recognizing the need for related risk reduction strategies to be based on robust scientific understanding, this study aims to combine remote sensing approaches with hydrodynamic flood modeling to identify key threats to lives and livelihoods.</p><p>This study also provides the first implementation of recently developed national guidelines on the management of GLOFs, where a detailed risk assessment including potential GLOF triggers, conditioning factors, and downstream impacts forms the scientific core. First results of only-water flow using HEC-RAS show that a high-potential scenario (dam breach depth = 40 m) produces flow depth and flow velocity up to 25 m and 9-12 m s<sup>-1</sup>, respectively, at Chungthang, a town located close to a major hydropower station, 62 km downstream of the lake. The fact that GLOF flow rheology is often changing as it propagates downstream, further modeling has been undertaken with r.avaflow, which can simulate the entire process chain from initial avalanche triggering, to dam erosion, and downstream flow propagation with a multi-phase modeling approach. Hence, we can evaluate the potential downstream impact in the case of a GLOF transitioning into a debris flow process. Our results provide flow hydraulics including flow velocities, flow heights, and total downstream inundation. These parameters will provide important insights for risk reduction strategies, such as early warning systems and land-use planning under current and future glacial conditions.</p><p> </p>

Glacial Lake Outburst Floods Early Warning System to save lives and livelihood of the Nepal Himalaya communities: A case Study of Imja Glacial Lake, Nepal 

2021 ◽  
Author(s):  
Deepak Kc ◽  
Top Khatri ◽  
Rishiram Sharma
Keyword(s):  
Climate Change ◽  
Risk Reduction ◽  
Early Warning ◽  
Early Warning System ◽  
Warning System ◽  
Glacial Lake ◽  
Glacial Lakes ◽  
Community Based ◽  
Outburst Floods ◽  
Glacial Lake Outburst Floods

<p>Nepal, a mountainous country, is experiencing multiple disasters, majority of which are induced by Climate Change. Erratic rainfall, extremely high temperature during summer, cold waves are some of them. Nepal will experience the impacts of climate change through an increase in temperature, more frequent heat waves and shorter frost durations in the future (5AR IPCC). Nepal is witnessing the increased maximum temperature of 0.56<sup>o</sup>C per decade and the increment of the temperature is even higher in the mountain region (ICIMOD 2019). One of the major impacts of Climate Change among others, is glacier retreat and Glacial Lake Outburst Floods (GLOFS). Nepal has already experienced more than 26 GLOFS (UNDP and ICIMOD 2020), originated both from Nepal and China, Tibet.</p><p>The Imja Glacial Lake is located at 27° 53′ 55“ N latitude, 86° 55’ 20” E longitude and at an altitude of 5010 m in Everest Region of Nepal Himalayas.  Imja was identified during 1960s as a small supra lake, was later expanded to an area of <strong>1.28 Km<sup>2</sup></strong>, <strong>148.9 meter deep</strong>, holding <strong>75.2 million cubic meters </strong>of water in 2014.   Lake lowering by 3.4 metres and establishment of early warning system was done in 2016 by the Government of Nepal and UNDP with the support of Global Environment Facility.  Hydro-met stations & GLOF Sensors in the periphery and downstream  of Imja Lake and automated early warning sirens in six prime settlements in the  downstream of Imja  watershed  linking with  dynamic SMS Alert system along 50 km downstream of Imja Dudh Koshi River have been have been linked with community-based DRM institutions at local government level. This initiative is important for preparedness and response of GLOF Risk Reduction in the Imja Valley, benefitting 71,752 vulnerable people, both local and the tourists visiting the Everest Region of Nepal.</p><p>Early Warning System of Tsho Rolpa Glacial Lake, the biggest Glacial Lake of Nepal is another example in the such system. New inventory of Glacial Lakes has identified 47 critical lakes as priority lakes for GLOF Risk Reduction in Koshi, Gandaki and Karnali basins. In the new context of federal  governance system, the role of federal, province and local government and communities is crucial  for achieving the targets of  Sendai Framework for Disaster Risk Reduction , particularly target “g” and SDGs 11 and 13  through integrating  the targets in the regular planning and   its’ implementation for resilient and Sustainable Development of  Nepal.</p><p><strong>References:</strong></p><p>Glacial lakes and glacial lake outburst floods in Nepal. Kathmandu, ICIMOD 2011,  Nepal Disaster Report, Ministry of Home affairs (MoHA) , 2015, 2018 Annual Reports UNDP 2016, 2017 and 2018,  Imja Hydro-Meteorological and Early Warning System User Manual, Government of Nepal and UNDP, 2017 Project Completion Report: Community Based Flood and Glacial Lake Outburst Risk Reduction Project, Government of Nepal and UNDP, 2017,  Inventory of glacial lakes and identification of potentially dangerous glacial lakes in the Koshi, Gandaki, and Karnali River Basins of Nepal, the Tibet Autonomous Region of China, and India. Research Report, ICIMOD and UNDP, 2020</p><p> </p>

scholarly journals A New Inclusive Volcanic Risk Ranking, Part 2: Application to Latin America

2021 ◽  
Vol 9 ◽  
Author(s):  
Letícia Freitas Guimarães ◽  
Amiel Nieto-Torres ◽  
Costanza Bonadonna ◽  
Corine Frischknecht
Keyword(s):  
Latin America ◽  
Risk Reduction ◽  
Latin American ◽  
Early Warning Systems ◽  
Volcanic Risk ◽  
Hazard Exposure ◽  
Risk Ranking ◽  
Reduction Strategies ◽  
Risk Reduction Strategies ◽  
Active Volcanoes

Volcanic Risk Ranking (VRR) methods have been developed worldwide as a way to hierarchize the volcanic systems and help target strategies for risk reduction. Such hierarchization is especially important in areas characterized by a large number of active volcanoes but limited resources. This is the case of Latin America, where large populations live nearby almost 300 active volcanoes. Here we assess the volcanic systems in Latin America with at least one eruption in the last 1,000 years based on the VRR strategy presented in a companion paper that accounts for the 4 main risk factors: hazard, exposure, vulnerability and resilience. Our results reveal that, among the 123 volcanoes analyzed, Santiaguito, Tacaná and Fuego are those with the highest score in the 3-factor VRR (H×E×V), while Ecuador, Marchena and Santiago are among the systems with the lowest score. Bárcena and Pinta score zero as there is no exposure. Although vulnerability significantly contributes to the VRR score, hazard and exposure are the main factors that define the risk of Latin American volcanic systems in the proposed 3-factor VRR, while resilience contributes to its reduction in the proposed 4-factor VRR strategy. In this regard, Arenal, Copahue, Villarrica, Ubinas, Irazú and Poás are the systems with the highest number of risk reduction strategies in place. Atitlán, Almolonga and Tecuamburro are the volcanic systems with the highest score in the 4-factor VRR [(H×E×V)/(Res+1)], combining moderate hazard, exposure and vulnerability and low resilience; Bárcena, Pinta, Ecuador, Marchena and Santiago receive the lowest scores due to no or low exposure. Santiaguito, Tacaná, El Chichón and Ceboruco are characterized by high scores in the 3-factor VRR and also stand out as some of those with few risk reduction strategies implemented; thus they have intermediate to high scores also in the 4-factor VRR. Recognizing that hazard is difficult to mitigate and reducing exposure may depend on hardly feasible relocation of infrastructure and already established communities, we emphasize that measures to reduce vulnerability and increase resilience should be promoted (e.g., creating redundancy/accessibility to infrastructure, carrying out risk assessment studies, implementing early warning systems, developing emergency plans and promoting educational activities).

scholarly journals Simulation and Assessment of Future Glacial Lake Outburst Floods in the Poiqu River Basin, Central Himalayas

Water ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1376
Author(s):  
Taigang Zhang ◽  
Weicai Wang ◽  
Tanguang Gao ◽  
Baosheng An
Keyword(s):  
River Basin ◽  
Hazard Assessment ◽  
Glacial Lake ◽  
High Mountain ◽  
Glacial Lakes ◽  
Central Himalayas ◽  
Outburst Floods ◽  
Glacial Lake Outburst Floods ◽  
Social And Economic Development ◽  
Glacial Lake Outburst Flood

A glacial lake outburst flood (GLOF) is a typical glacier-related hazard in high mountain regions. In recent decades, glacial lakes in the Himalayas have expanded rapidly due to climate warming and glacial retreat. Some of these lakes are unstable, and may suddenly burst under different triggering factors, thus draining large amounts of water and impacting downstream social and economic development. Glacial lakes in the Poiqu River basin, Central Himalayas, have attracted great attention since GLOFs originating there could have a transboundary impact on both China and Nepal, as occurred during the Cirenmaco GLOF in 1981 and the Gongbatongshaco GLOF in 2016. Based on previous studies of this basin, we selected seven very high-risk moraine-dammed lakes (Gangxico, Galongco, Jialongco, Cirenmaco, Taraco, Beihu, and Cawuqudenco) to simulate GLOF propagation at different drainage percentage scenarios (i.e., 25%, 50%, 75%, and 100%), and to conduct hazard assessment. The results show that, when any glacial lake is drained completely or partly, most of the floods will enter Nepal after raging in China, and will continue to cause damage. In summary, 57.5 km of roads, 754 buildings, 3.3 km2 of farmland, and 25 bridges are at risk of damage due to GLOFs. The potentially inundated area within the Chinese part of the Poiqu River basin exceeds 45 km2. Due to the destructive impacts of GLOFs on downstream areas, appropriate and effective measures should be implemented to adapt to GLOF risk. We finally present a paradigm for conducting hazard assessment and risk management. It uses only freely available data and thus is easy to apply.

scholarly journals Hazards of Risk: Identifying Plausible Community Wildfire Disasters in Low-Frequency Fire Regimes

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 934
Author(s):  
Andy McEvoy ◽  
Becky K. Kerns ◽  
John B. Kim
Keyword(s):  
Risk Reduction ◽  
Low Frequency ◽  
Fire Regimes ◽  
Cascade Range ◽  
Private Land ◽  
Wildfire Risk ◽  
Location Data ◽  
Reduction Strategies ◽  
Community Exposure ◽  
Risk Reduction Strategies

Optimized wildfire risk reduction strategies are generally not resilient in the event of unanticipated, or very rare events, presenting a hazard in risk assessments which otherwise rely on actuarial, mean-based statistics to characterize risk. This hazard of actuarial approaches to wildfire risk is perhaps particularly evident for infrequent fire regimes such as those in the temperate forests west of the Cascade Range crest in Oregon and Washington, USA (“Westside”), where fire return intervals often exceed 200 years but where fires can be extremely intense and devastating. In this study, we used wildfire simulations and building location data to evaluate community wildfire exposure and identify plausible disasters that are not based on typical mean-based statistical approaches. We compared the location and magnitude of simulated disasters to historical disasters (1984–2020) in order to characterize plausible surprises which could inform future wildfire risk reduction planning. Results indicate that nearly half of communities are vulnerable to a future disaster, that the magnitude of plausible disasters exceeds any recent historical events, and that ignitions on private land are most likely to result in very high community exposure. Our methods, in combination with more typical actuarial characterizations, provide a way to support investment in and communication with communities exposed to low-probability, high-consequence wildfires.

Prevention of Breast Cancer (Part II): Risk Reduction Strategies

2010 ◽  
Vol 28 (10) ◽  
pp. 1070-1077 ◽  
Author(s):  
Maria Tria Tirona ◽  
Rajesh Sehgal ◽  
Oscar Ballester
Keyword(s):  
Breast Cancer ◽  
Risk Reduction ◽  
Reduction Strategies ◽  
Risk Reduction Strategies ◽  
Prevention Of Breast Cancer

Impact of the New York State Prescription Drug Monitoring Program (IStop) on chronic pain management by primary care providers

2021 ◽  
Vol 17 (1) ◽  
pp. 39-54
Author(s):  
Josiah D. Strawser, MD ◽  
Lauren Block, MD, MPH
Keyword(s):  
Primary Care ◽  
Chronic Pain ◽  
Pain Management ◽  
Risk Reduction ◽  
New York State ◽  
Monitoring Program ◽  
Primary Care Providers ◽  
Care Providers ◽  
Reduction Strategies ◽  
Risk Reduction Strategies

Objective: To explore the impact of the New York State Prescription Drug Monitoring Program (IStop) on the self-reported management of patients with chronic pain by primary care providers.Design: Mixed-methods study with survey collection and semistructured interviews.Setting: Multiple academic hospitals in New York.Participants: One hundred and thirty-six primary care providers (residents, fellows, attendings, and nurse practitioners) for survey collection, and eight primary care clinicians (residents, attending, and pharmacist) for interviews. Interventions: Introduction of IStop.Main outcome measure(s): Change in usage of four risk reduction strategies (pain contracts, urine tests, monthly visits, and co-management) as reported by primary care providers for patients with chronic pain.Results: After the introduction of IStop, 25 percent (32/128) of providers increased usage of monthly visits, 28 percent (36/128) of providers increased usage of pain management co-management with other healthcare providers, and 46 percent (60/129) of providers increased usage of at least one of four risk reduction strategies. Residents indicated much higher rates of change in risk reduction strategies due to IStop usage; increasing in the use of monthly visits (32 vs. 13 percent, p = 0.02) and co-management (36 vs. 13 percent, p = 0.01) occurred at a much higher rate in residents than attending physicians. Interview themes revealed an emphasis on finding opioid alternatives when possible, the need for frequent patient visits in effective pain management, and the importance of communication between the patient and provider to protect the relationship in chronic pain management.Conclusions: After the introduction of IStop, primary care providers have increased usage of risk reduction strategies in the care of chronic pain patients.

scholarly journals Evaluation of flood risk reduction strategies through combinations of interventions

2018 ◽  
Vol 12 (S2) ◽  
Author(s):  
Erik C. Berchum ◽  
William Mobley ◽  
Sebastiaan N. Jonkman ◽  
Jos S. Timmermans ◽  
Jan H. Kwakkel ◽  
...  
Keyword(s):  
Risk Reduction ◽  
Flood Risk ◽  
Reduction Strategies ◽  
Flood Risk Reduction ◽  
Risk Reduction Strategies

scholarly journals Inadequate stakeholder management and its effect on a coherent sinkhole risk management strategy: The case of the Merafong Local Municipality, South Africa

2016 ◽  
Vol 8 (1) ◽  
Author(s):  
Tshepo Moshodi ◽  
Christo Coetzee ◽  
Kristel Fourie
Keyword(s):  
Risk Management ◽  
Risk Reduction ◽  
Community Involvement ◽  
Stakeholder Management ◽  
Current Status ◽  
Community Stakeholders ◽  
Management Processes ◽  
Reduction Strategies ◽  
Local Municipality ◽  
Risk Reduction Strategies

The Merafong Local Municipality (MLM) has historically suffered financial and human losses because of the presence of dolomite and the consequent formation of sinkholes. There is a great need for the MLM to address the risk posed by sinkholes to ensure the continued safety of communities. However, as the risk is so pervasive, the MLM needs to coordinate their risk reduction strategies with a wide array of stakeholders in the municipality. Efficient stakeholder management is thus crucial if the sinkhole risk is to be addressed appropriately. This article reviews the current status of stakeholder management in the MLM as it pertains to the formulation of a holistic sinkhole risk reduction strategy. Findings indicate that there are serious deficiencies in the MLM’s stakeholder management relating to key risk management processes such as community involvement in risk management structures, disaster risk assessment, training and awareness, and early warning and response. Improved stakeholder management could be characterised by the following factors: improved two-way communication between the municipality and community stakeholders, fostering a relationship based upon trust and equality amongst stakeholders, participation by a wide array of stakeholder groups affected by the sinkhole risk and a mutual commitment by all stakeholders to address the risk. These factors could contribute to enhancing current and future sinkhole risk reduction strategies.

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