Multi-Hazard Chain Reaction Initiated by the 2020 Meilong Debris Flow in the Dadu River, Southwest China

Lan, Ning; Hu, Kaiheng; Wang, Zhang; Luo, Hong; Qin, Haokun; Zhang, Xiaopeng; Liu, Shuang

doi:10.3389/feart.2022.827438

Cited by 11 publications

(3 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Second, buildings should not be constructed near debris flow gullies, and new buildings should be built on elevated ground or at certain elevations above the ground (Attems et al, 2019). Third, deflection walls should be considered and constructed in villages susceptible to debris flows to protect entire buildings (Wang et al, 2022), and flood protection walls should be built along the main river to protect the entire flood-prone village.…”

Section: The Implication Of Hazard Mitigationmentioning

confidence: 99%

The vulnerability of buildings to a large-scale debris flow and outburst flood hazard chain that occurred on 30 August 2020 in Ganluo, Southwest China

Liu

et al. 2023

Preprint

View full text Add to dashboard Cite

Abstract. In mountainous areas, damage caused by debris flows is often aggravated by subsequent dam-burst floods within the main river confluence zone. On 30 August 2020, a catastrophic disaster chain occurred at the confluence of the Heixiluo Gully and Niri River in Ganluo County, Southwest China, that consisted of a debris flow, the formation of a barrier lake and subsequent dam breach that flooded the community. This study provides a comprehensive analysis of the damage to buildings resulting from the sequential occurrence of debris flow and dam-burst flood. The peak discharge of the debris flow in the gully mouth reached 1937 m3/s, and the change in the main river channel resulting from the dam-burst flood, which had a peak discharge of 2273 m3/s, resulted in a fourfold increase in the extent of flood inundation compared to an ordinary flood. Three hazard zones were established based on the building damage patterns: (I) primary debris flow burial; (II) secondary dam-burst flood inundation and (III) sequential debris flow burial and dam-burst inundation. Vulnerability curves were developed for Zone (II) and Zone (III) using impact pressures and inundation depths, and a vulnerability assessment chart is presented that contains the three damage categories. This research addresses a gap in the vulnerability assessments of debris flow hazard chains and can support in future disaster mitigation within confluence areas.

show abstract

Section: The Implication Of Hazard Mitigationmentioning

confidence: 99%

The vulnerability of buildings to a large-scale debris flow and outburst flood hazard chain that occurred on 30 August 2020 in Ganluo, Southwest China

Liu

et al. 2023

Preprint

View full text Add to dashboard Cite

show abstract

“…Hydropower toppling deformation slopes comprise the largest proportion and are distributed widely along the Yalong River basin [14,[39][40][41][42][43][44][45], the Lancang River basin [8,[46][47][48][49][50][51][52][53][54][55][56][57], the Yellow River basin [19,[58][59][60][61][62][63][64], the Dadu River basin [65][66][67][68], the Nu River basin [69], the Min River basin [70], the Bailong River basin [71,72], the Tao River basin [73,74], the Kezier River basin [75,76], the Xixi River basin and a river basin in Xinjiang [77].…”

Section: Toppling Deformation Statisticsmentioning

confidence: 99%

Development Pattern of Toppling Deformation Slopes in Western China

Li,

Cao,

Huang

et al. 2023

Applied Sciences

View full text Add to dashboard Cite

Controlled by regional geological background, and affected by human activity and weathering, toppling deformation slopes occur in different regions in China. Based on statistics about domestic toppling deformation slopes and their distribution, the regional geological susceptibility zonation area of toppling deformation slopes was determined. Firstly, a regional geological susceptibility evaluation was conducted according to these toppling deformation slopes, choosing landform, stratigraphic age, seismic intensity and tectonic stress distribution, and the study area was divided into very low, low, medium, high and very high susceptibility areas. Secondly, a geographic position susceptibility evaluation was conducted aimed at different sections of typical rivers in western China and the toppling deformation slopes related to them, and the study area was divided into upstream, midstream and downstream of 11 rivers that were respectively classified into very low, low, high and very high susceptibility areas. Thirdly, based on the results, associations between the toppling deformation factors (lithology, slope height, elevation, horizontal depth and vertical depth) and the distribution of deformation slopes were revealed. Finally, the development regularity was analyzed comprehensively. The results show that the toppling deformation slopes of hydropower projects are more developed in Sichuan, Qinghai and Yunnan provinces of China. With regard to regional geography, besides the Yellow River, both the Lancang River and the Yalong River flow through areas with toppling deformation that are classified as highly susceptible geological zones in all levels. The results of this study can be used as references for site selection plans in hydropower projects.

show abstract

“…A simulation was conducted to analyze the movement and accumulation process of MLG debris flow . Additionally, Ning et al (2022) analyzedthe implementation of engineering measures aimed at slowing down and reducing the ongoing development of the MLG hazard chain. Liu et al (2023a) conducted numerical simulations of the XJC river dam failure process and identified that the channel uplift resulting from the dam failure exacerbated the flood hazard of the MLG hazard chain.…”

Section: Introductionmentioning

confidence: 99%

Causal mechanisms and evolution processes of “block-burst” debris flow hazard chains in mountainous urban areas: a case study of Meilong gully in Danba county, Sichuan Province, China

Shen,

Yang,

et al. 2024

Front. Earth Sci.

View full text Add to dashboard Cite

The research interest in multi-hazard chains lies in the comprehension of how various hazards, such as debris flows, floods, and landslides, can interact and amplify one another, resulting in cascading or interconnected hazards. On 17 June 2020, at approximately 3:20 a.m., a debris flow occurred in Meilong gully (MLG), located in Banshanmen Town, Danba County, in southwest China’s Sichuan Province. The debris flow had a discharge volume of approximately 40 × 104 m3 and rushed out to block the Xiaojinchuan (XJC) river, subsequently forming a barrier lake. This event ultimately induced a hazard chain that included heavy rainfall, debris flow, landslides, the formation of a barrier lake, and an outburst flood. The impact of this chain resulted in the displacement of 48 households and affected 175 individuals. Furthermore, it led to the destruction of an 18 km section of National Highway G350, stretching from Xiaojin to Danba County, causing economic losses estimated at 65 million yuan. The objective of this study is to analyze the factors leading to the formation of this hazard chain, elucidate its triggering mechanisms, and provide insights for urban areas in the western mountainous region of Sichuan to prevent similar dam-break type debris flow hazard chains. The research findings, derived from field investigations, remote sensing imagery analysis, and parameter calculations, indicate that prior seismic disturbances and multiple dry-wet cycle events increased the volume of loose solid materials within the MLG watershed. Subsequently, heavy rainfall triggered the initiation of the debris flow in MLG. The cascading dam-break, resulting from three unstable slopes and boulders within the channel, amplified the scale of the hazard chain, leading to a significant amount of solid material rushing into the XJC river, thus creating a dam that constricted the river channel. With the intensification of river scouring, the reactivation and destabilization of the Aniangzhai (ANZ) paleolandslide occurred, ultimately leading to the breach of the dam and the formation of an outburst flood. The research comprehensively and profoundly reveals the causal mechanism of the MLG hazard chain, and proposes measures to disrupt the chain at various stages, which can aid in enhancing monitoring, early warning, forecasting systems, and identifying key directions for ecological environmental protection in urban areas within the western mountainous region of Sichuan. Additionally, it could also serve as a reference for mountainous urban areas such as the Tianshan, Alps, Rocky Mountains, and Andes, among others.

show abstract

Multi-Hazard Chain Reaction Initiated by the 2020 Meilong Debris Flow in the Dadu River, Southwest China

Cited by 11 publications

References 34 publications

The vulnerability of buildings to a large-scale debris flow and outburst flood hazard chain that occurred on 30 August 2020 in Ganluo, Southwest China

The vulnerability of buildings to a large-scale debris flow and outburst flood hazard chain that occurred on 30 August 2020 in Ganluo, Southwest China

Development Pattern of Toppling Deformation Slopes in Western China

Causal mechanisms and evolution processes of “block-burst” debris flow hazard chains in mountainous urban areas: a case study of Meilong gully in Danba county, Sichuan Province, China

Contact Info

Product

Resources

About