Risk Assessment of Population Loss Posed by Earthquake-Landslide-Debris Flow Disaster Chain: A Case Study in Wenchuan, China

Earthquakes often cause secondary disasters in mountainous areas, forming the typical earthquake-landslide-debris flow disaster chain for a long time that results in a series of losses. It is important to improve the risk assessment method from the perspective of cascading effect of such a disaster chain, by strengthening quantitative research on hazards of the debris flows which are affected by landslide volume and rainstorm intensity. Taking Wenchuan County as an example, the risk assessment method for population loss of the disaster chain is established and the risks are evaluated in this paper. The results show that the population loss risk is 2.59–2.71 people/km2 under the scenarios of the Wenchuan Ms8.0 earthquake and four rainstorm intensities. The impacts of landslide and debris flow after the earthquake were long-term and profound. A comparison of risks caused by each element of the chain revealed that the risk associated with the earthquake accounted for the highest proportion, and landslide and debris flow accounted for 38.82–37.18% and 3.42–7.50%, respectively. As the earthquake intensity increases, the total risk posed by the disaster chain increases significantly. The risk caused by the earthquake is the highest in high earthquake intensity zones; while in the lower-intensity zones, landslides and debris flows pose relatively high risks. The risk assessment results were verified through comparison with actual data, indicating that the simulation results are quite consistent with the existing disaster information and that the risk assessment method based on the earthquake-landslide-debris flow cascade process is significant for future risk estimation.

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Mortality risk assessment for earthquake-landslide-debris flow disaster chain under different scenarios: A case study in Wenchuan, China

10.5194/egusphere-egu21-13026 ◽

2021 ◽

Author(s):

Xiang Han ◽

Yunhe Yin ◽

Shaohong Wu

Keyword(s):

Debris Flow ◽

Factor Model ◽

Total Mortality ◽

Assessment Method ◽

Control Measures ◽

Mortality Risks ◽

Disaster Chain ◽

The Impact ◽

Debris Flow Disaster ◽

Landslide Debris

Earthquake-geological disaster chain is one of the common forms of multi-disasters. Primary disaster and secondary disaster are cascaded, which often leads to the expansion of disaster losses. Since the ms8.0 earthquake in 2008, Wenchuan has continued to have landslides and debris flow disasters, which leads to the possibility of forming an earthquake-landslide-debris flow disaster chain, and the risk of population mortality. This study analyzes the key links in the formation of the earthquake-landslide-debris flow disaster chain in Wenchuan. Then according to the disaster chain assessment method, considering the impact of key factors in the disaster cascade effect, a factor model for the disaster chain is established. And mortality risks of the regional disaster chain under earthquake and heavy rainfall scenarios are quantified. The mortality risks of the earthquake-landslide-debris flow disaster chain &#160;are 2.82 people/km2, 2.90 people/km2, 2.92 people/km2, and 2.95 people/km2 with the precipitation probability of 20%, 5%, 2% and 1% .&#160;The&#160;risk&#160;for earthquake&#160;accounts for 50.98%~51.54%, the landslide&#160;accounts for 33.90%~34.28%, and the debris flow&#160;accounts for 14.19~15.12%&#160;in Wenchuan. At the township level, the total mortality&#160;risks&#160;of Yinxing, Yingxiu, and Gengda are&#160;at a relatively high level in this&#160;region.&#160;These results could provide a basis for further investigating and quantifying the risk reduction measurements of earthquake-landslide-debris flow disaster chain based on which effective disaster prevention and control measures can be undertaken.

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Risk Assessment and Control Measure of Debris Flow in Chunyashu Gully of Seismic Disastrous Area of Sichuan Province

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.446-449.2988 ◽

2012 ◽

Vol 446-449 ◽

pp. 2988-2991

Author(s):

Ji Hua Chen ◽

Hui Ge Wu ◽

Hai Hui Zhou ◽

Hai Liang Zhang

Keyword(s):

Risk Assessment ◽

Debris Flow ◽

Wenchuan Earthquake ◽

Debris Flows ◽

Loose Material ◽

Control Measure ◽

Assessment Method ◽

Sichuan Province ◽

The Wenchuan Earthquake ◽

And Control

The terrain of Chunyashu gully in Dujiangyan city of Sichuan province was steep, plenty of loose material increased after the Wenchuan earthquake. Debris flows were triggered in September 2008 and August 2009, and the debris flow was a serious threat to the highway and the residents. Risk of Chunyashu gully debris flow had been analyzed by the latest assessment method, and the result was that the risk degree of this gully was middle. Finally according to the local situation the control measure of interception dam and other advices had been suggested to protect the safety of the residents.

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Mechanism and risk assessment of landslide-triggered-debris flows: Lesson from the 1996.12.6 Otari debris flow disaster, Nagano, Japan

Landslide Risk Assessment ◽

10.1201/9780203749524-24 ◽

2018 ◽

pp. 347-356 ◽

Cited By ~ 3

Author(s):

Kyoji Sassa ◽

Hiroshi Fukuoka ◽

Wang Fawu

Keyword(s):

Risk Assessment ◽

Debris Flow ◽

Debris Flows ◽

Debris Flow Disaster

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Risk assessment method of debris flow occurrence utilizing a digital terrain model

Monitoring, Stimulation, Prevention and Remediation of Dense and Debris Flows IV ◽

10.2495/deb120081 ◽

2012 ◽

Author(s):

O. Nunokawa ◽

T. Sugiyama ◽

N. Ota ◽

K. Okada ◽

T. Fujii

Keyword(s):

Risk Assessment ◽

Debris Flow ◽

Digital Terrain Model ◽

Assessment Method ◽

Terrain Model ◽

Digital Terrain ◽

Risk Assessment Method

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Risk Assessment and Disaster Prevention and Mitigation Strategies for Large-Scale Sediment Disasters

10.5194/egusphere-egu21-11841 ◽

2021 ◽

Author(s):

Shin-Ping Lee ◽

Yuan-Jung Tsai ◽

Yun-Chung Tsang ◽

Ching-Ya Tsai ◽

Shang-Ming Wang ◽

...

Keyword(s):

Climate Change ◽

Risk Assessment ◽

Debris Flows ◽

Large Scale ◽

Assessment Method ◽

Disaster Prevention ◽

Typhoon Morakot ◽

Risk Assessment Method ◽

Landslides And Debris Flows ◽

The Impact

Under climate change impact, the frequency of extreme hydrological events increases. The occurrence of extreme rainfall events may lead to large-scale flooding or sediment disasters resulting in serious property damage and casualties. Large-scale sediment disasters include large-scale landslides and debris flows which are the main types of disasters causing casualties. In Taiwan, during Typhoon Morakot in 2009, the long duration and high-intensity rainfall led to a large-scale sediment disaster resulting in heavy casualties. A disaster with certain magnitude and complexity cannot be coped with a single disaster management approach. In this study, a risk assessment method considering climate change impacts proposed by the Intergovernmental Panel on Climate Change (IPCC) was adopted. By analyzing hazard, exposure, and vulnerability indicators of large-scale sediment disasters in Xinfa catchment of Kaohsiung City, Taiwan, a disaster risk adaptation strategy was proposed based on the impact of disaster factors.Two scenarios were applied for the catchment sediment hazards risk assessments including 50-year recurrence period (high frequency and low impact) and extreme scenario (low frequency and high impact). Multiple factors for hazard (impact area of landslides and debris flows), exposure (lifeline roads and land use intensity), and vulnerability (disaster prevention and relief resources and settlement population characteristics) assessments were considered. The correlation factor selection and weighting analysis was calibrated by the 2009 Typhoon Morakot event. All disaster-recorded locations were above moderate risk indicating that the risk assessment method was reasonable. A risk map for Xinfa catchment was completed based on the validated risk assessment model to identify the high-risk settlements. After analyzing the spatial characteristics and disaster risk impact factors of high-risk settlements, both software and hardware disaster prevention measures and adaptation strategies were suggested. According to the analyzed results, although the hardware measures were effective in reducing sediment hazards generally, under extreme hydrologic events, those measures could be ineffective due to limited protection capacity of the engineering facilities. Hence, reducing exposure and vulnerability is essential to deal with the impact of extreme events.Keywords: Large-scale sediment disasters, Risk assessment, Adaptation strategies

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Risk Assessment Method for Transmission-distribution Integrated System with Distributed PV

2018 2nd IEEE Conference on Energy Internet and Energy System Integration (EI2) ◽

10.1109/ei2.2018.8582661 ◽

2018 ◽

Cited By ~ 1

Author(s):

Chunlei Xu ◽

Dasong Sun ◽

Yi Tang ◽

Jing Yu ◽

Haiwei Wu

Keyword(s):

Risk Assessment ◽

Assessment Method ◽

Integrated System ◽

Risk Assessment Method

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Storm surge risk assessment method for a coastal county in China: case study of Jinshan District, Shanghai

Stochastic Environmental Research and Risk Assessment ◽

10.1007/s00477-020-01791-3 ◽

2020 ◽

Vol 34 (5) ◽

pp. 627-640 ◽

Cited By ~ 3

Author(s):

Shi Xianwu ◽

Qiu Jufei ◽

Chen Bingrui ◽

Zhang Xiaojie ◽

Guo Haoshuang ◽

...

Keyword(s):

Risk Assessment ◽

Storm Surge ◽

Assessment Method ◽

Risk Assessment Method ◽

Coastal County

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A Methodology for Harmonizing Safety and Health Scales in Occupational Risk Assessment

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18094849 ◽

2021 ◽

Vol 18 (9) ◽

pp. 4849

Author(s):

Zuzhen Ji ◽

Dirk Pons ◽

John Pearse

Keyword(s):

Risk Assessment ◽

Health And Safety ◽

Assessment Method ◽

Assessment Process ◽

Successful Implementation ◽

Health Issues ◽

Public Health Perspective ◽

Chronic Health ◽

Risk Assessment Method

Successful implementation of Health and Safety (H&S) systems requires an effective mechanism to assess risk. Existing methods focus primarily on measuring the safety aspect; the risk of an accident is determined based on the product of severity of consequence and likelihood of the incident arising. The health component, i.e., chronic harm, is more difficult to assess. Partially, this is due to both consequences and the likelihood of health issues, which may be indeterminate. There is a need to develop a quantitative risk measurement for H&S risk management and with better representation for chronic health issues. The present paper has approached this from a different direction, by adopting a public health perspective of quality of life. We have then changed the risk assessment process to accommodate this. This was then applied to a case study. The case study showed that merely including the chronic harm scales appeared to be sufficient to elicit a more detailed consideration of hazards for chronic harm. This suggests that people are not insensitive to chronic harm hazards, but benefit from having a framework in which to communicate them. A method has been devised to harmonize safety and harm risk assessments. The result was a comprehensive risk assessment method with consideration of safety accidents and chronic health issues. This has the potential to benefit industry by making chronic harm more visible and hence more preventable.

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