Geomorphic effect of debris-flow sediments on the Min River, Wenchuan Earthquake region, western China

2021 ◽  
Vol 18 (9) ◽  
pp. 2427-2440
Author(s):  
Xu-dong Hu ◽  
Li-qin Zhou ◽  
Wei-ming Liu ◽  
Hao Wang ◽  
Lei Cui
Keyword(s):  
Debris Flow ◽  
Wenchuan Earthquake ◽  
Western China ◽  
Min River

Key Problems on Debris Flow Control Engineering after Wenchuan Earthquake in China

2020 ◽  
Author(s):  
Yanchao Gao ◽  
Songjiang Zhao ◽  
Jiazhu Wang ◽  
Wei Xu
Keyword(s):  
Debris Flow ◽  
Wenchuan Earthquake ◽  
Debris Flows ◽  
Large Scale ◽  
Control Measures ◽  
Western China ◽  
Design Parameters ◽  
Disaster Prevention ◽  
Check Dam ◽  
Control Engineering

<p>Strong earthquakes often induce a substantial rise in secondary geohazards. This problem has been studied more after the Great Kanto Earthquake in Japan and the Chichi Earthquake in Taiwan. In western China, after the 2008 M<sub>w</sub>7.9 Wenchuan earthquake, large-scale regional debris flows occurred in 2008, 2009, 2010, 2011, 2013, 2014, and 2019 in the strong earthquake zone. Many control projects have been constructed, including more than 1,000 check dams. Part of the projects were damaged in the subsequent large debris flows. Debris flow after the earthquake is characterized by many loose sources, high frequency and large magnitude. Traditional design parameters and control engineering cannot meet disaster prevention requirements. In the 11 years after the Wenchuan earthquake, our research team continued to investigate the formation of the debris flow in the earthquake area, and summarized the reasons for the failure of the control projects, such as the low estimate of the loose sources and the insufficient design capacity of the check dam. In response to the above problems, we have proposed corresponding solutions, including the optimal combination of different control measures, the design of the dam site and storage capacity, and the structural form of the check dam. This optimization concept has been applied in debris flow prevention such as Qipan gully and Shaofang gully and has achieved good control results. The research provides a reference for subsequent disaster prevention and mitigation in similar earthquake areas.</p>

scholarly journals Application and analysis of debris-flow early warning system in Wenchuan earthquake-affected area

2016 ◽  
Vol 16 (2) ◽  
pp. 483-496 ◽  
Author(s):  
D. L. Liu ◽  
S. J. Zhang ◽  
H. J. Yang ◽  
L. Q. Zhao ◽  
Y. H. Jiang ◽  
...  
Keyword(s):  
Debris Flow ◽  
Wenchuan Earthquake ◽  
Early Warning ◽  
Early Warning System ◽  
Prediction Accuracy ◽  
Warning System ◽  
Sichuan Province ◽  
Affected Area ◽  
The Wenchuan Earthquake ◽  
New System

Abstract. The activities of debris flow (DF) in the Wenchuan earthquake-affected area significantly increased after the earthquake on 12 May 2008. The safety of the lives and property of local people is threatened by DFs. A physics-based early warning system (EWS) for DF forecasting was developed and applied in this earthquake area. This paper introduces an application of the system in the Wenchuan earthquake-affected area and analyzes the prediction results via a comparison to the DF events triggered by the strong rainfall events reported by the local government. The prediction accuracy and efficiency was first compared with a contribution-factor-based system currently used by the weather bureau of Sichuan province. The storm on 17 August 2012 was used as a case study for this comparison. The comparison shows that the false negative rate and false positive rate of the new system is, respectively, 19 and 21 % lower than the system based on the contribution factors. Consequently, the prediction accuracy is obviously higher than the system based on the contribution factors with a higher operational efficiency. On the invitation of the weather bureau of Sichuan province, the authors upgraded their prediction system of DF by using this new system before the monsoon of Wenchuan earthquake-affected area in 2013. Two prediction cases on 9 July 2013 and 10 July 2014 were chosen to further demonstrate that the new EWS has high stability, efficiency, and prediction accuracy.

scholarly journals Analysis of a debris flow after Wenchuan Earthquake and discussion on preventive measures

2019 ◽  
Vol 23 (3 Part A) ◽  
pp. 1563-1570
Author(s):  
Zhi-Long Zhang ◽  
Jing Xie ◽  
De-Ke Yu ◽  
Zhi-Jie Wen
Keyword(s):  
Debris Flow ◽  
Wenchuan Earthquake ◽  
Preventive Measures ◽  
Impact Force ◽  
Site Investigation ◽  
The Wenchuan Earthquake ◽  
Formation Conditions ◽  
National Road ◽  
And Control ◽  
Debris Flow Disaster

This paper addresses a debris flow disaster in Yingxiu town after the Wenchuan earthquake. Through site investigation and data review, the geography and geological environment of the basin and the development, formation conditions and activity characteristics of the debris flow in the basin are analyzed. Calculate and analyze the characteristics of the debris flow, such as gravity, flow velocity and impact force. According to the management idea of combination of blocking and discharging, this paper proposes to arrange three blocking dams in the main ditch, construct drainage gullies in the downstream accumulation section, and prevent and control the aqueduct in the intersection of the main ditch and the G213 national road, which will be similar to the earthquake in the future. It is provided as a reference for research and prevention of the debris flow.

Characteristics, Hazards and Mitigation of Debris Flows Along Min River after the Wenchuan Earthquake

2012 ◽  
pp. 975-987 ◽  
Author(s):  
Yonggang Ge ◽  
Peng Cui ◽  
Xingzhang Chen ◽  
Xinghua Zhu ◽  
Lingzhi Xiang
Keyword(s):  
Wenchuan Earthquake ◽  
Debris Flows ◽  
Min River ◽  
The Wenchuan Earthquake

scholarly journals Characteristics and Prevention of the Debris Flows following Wenchuan Earthquake in Jushui River Basin, An County, China

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Yonggang Ge ◽  
Jianqiang Zhang ◽  
Xiaojun Guo
Keyword(s):  
Debris Flow ◽  
Wenchuan Earthquake ◽  
River Basin ◽  
Debris Flows ◽  
Flash Flood ◽  
River Channel ◽  
Hazard Identification ◽  
Control Mode ◽  
Potential Hazard ◽  
Prevention Measures

After analysing the catastrophic debris flows on August 18, 2012, and on July 9, 2013, in Jushui River basin, An County, the Wenchuan Earthquake seriously striken areas, it was found that they were characterized by the clay soil content of 0.1~1.2%, the density of 1.68~2.03 t/m3, the discharges of 62.2 m3/s to 552.5 m3/s, and the sediment delivery modulus of 1.0~9.4 × 104 m3/km2. Due to intense rainstorm, many large debris flows produced hazard chain, involved in flash flood, debris flow, dammed lake, and outburst flood, and rose Jushui River channel about 1~4 m as well as amplified flood. The hazards and losses mainly originated from the burying and scouring of debris flows, flood inundating, and river channel rise. The prevention of debris flows is facing the intractable problems including potential hazard identification, overstandard debris flow control, control constructions destructing, and river channel rapid rise. Therefore, the prevention measures for the basin, including hazard identification and risk assessment, inhabitants relocating, monitoring and alarming network establishing, emergency plans founding, and river channel renovating, and the integrated control mode for watershed based on regulating the process of debris flow discharge, were recommended for mitigation.

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