Characteristics and Risk Assessment of Group Landslide-Debris Flow Disaster Chain in the Hilly Mountains of South China: A Case Study of the Magui River Basin in Gaozhou, Western Guangdong

The current risk assessment of single landslides and debris flow disasters ignores the increasing supply, accumulation, and superposition amplification effects of disasters from top to bottom, resulting in a serious underestimation of the risk of landslide-debris flow disaster chains. This study tak...

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Main Authors: Shen Qiuhua, Wang Jun, Li Hao, Gong Qinghua, Li Nianqin, Li Jingfu, Yuan Shaoxiong, Liu Bowen
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Language:zho
Published: Editorial Committee of Tropical Geography 2025-04-01
Series:Redai dili
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Online Access:https://www.rddl.com.cn/CN/10.13284/j.cnki.rddl.20240793
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author Shen Qiuhua
Wang Jun
Li Hao
Gong Qinghua
Li Nianqin
Li Jingfu
Yuan Shaoxiong
Liu Bowen
author_facet Shen Qiuhua
Wang Jun
Li Hao
Gong Qinghua
Li Nianqin
Li Jingfu
Yuan Shaoxiong
Liu Bowen
author_sort Shen Qiuhua
collection DOAJ
description The current risk assessment of single landslides and debris flow disasters ignores the increasing supply, accumulation, and superposition amplification effects of disasters from top to bottom, resulting in a serious underestimation of the risk of landslide-debris flow disaster chains. This study takes the "2010.9.21" mega-landslide debris flow disaster in the Magui River Basin in Gaozhou, western Guangdong as a case study. A landslide-debris flow disaster chain risk assessment index system, guided by the cumulative amplification effect, was established from the perspective of disaster chain initiation, transmission, and cumulative amplification. A comprehensive index model was used to scientifically evaluate the risk of the disaster chain, and actual investigation results were used for verification. The results are as follows: 1) The landslide-debris flow disaster chain in the Magui River Basin is characterized by multi-ditch collection, high impact force, and major terrain fluctuation. The landslide in the starting area is directly transformed into a debris flow during the instability process and flows into the debris flow branch ditch over a short distance. Several debris-flow branches received landslides along the path, converging into the main ditch. After potential energy accelerates through the circulation area, the flow rushes out of the ditch, leading to a large area of fan-shaped accumulations in the low- and slow-terrain areas, causing serious damage to residential houses and farmland. 2) A total of one small watershed unit carries an extremely high risk, accounting for 2.04% of the total number of small watersheds. The extremely high-risk area covers 3.64 km2, accounting for 2.24% of the total area. It is mainly distributed in a small watershed east of Liutang Village. There were eight small watersheds in high-risk areas, accounting for 16.33% of the total small watershed number. The dangerous area covers an area of 20.50 km2, accounting for 12.62% of the total area. Most watersheds are concentrated in Langlian Village, Shenshui Village, Makeng Village, and northern Longkeng Village in the Middle East region of Liutang Village. The number of small watersheds in the medium-risk area was 18, accounting for 36.73% of all the small watersheds, and the total area covered by dangerous area was 81.22 km2, accounting for approximately 44.90% of the total study area. The medium-risk areas were widely distributed within the scope of the study, especially in the southern part of Longkeng Village, most of the small watersheds of Liutang Village, the southern part of Langlian Village, Magui Village, Chengdong Village, Gancheng Village, the central area of Daxi Village, Houyuan Village, and Shanxin Village. There were 22 small watersheds in the low-risk area, accounting for 48.98% of the total number of small watersheds. The low-risk area covers 57.07 km2, accounting for 35.13% of the total study area. It is mainly distributed in the small watersheds of Shanxin Village, Houyuan Village South, Yadong Village South, and Zhoukeng Village in the northeast; Daxi Village in the west; Hemudong Village in the central region; and Longkeng Village in the south. 3) The evaluation results of this study were verified using actual investigation data, which showed high consistency with field survey results, thereby confirming the credibility of the method employed in this study. The index system and evaluation approach for the risk assessment of mass landslide-debris flow disaster chains proposed in this paper can serve as a reference for risk studies of landslide-debris flow disaster chains in South China and other similar areas.
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spelling doaj-art-dbd3ebe03c1f4824b54952450ef27e612025-08-20T03:10:10ZzhoEditorial Committee of Tropical GeographyRedai dili1001-52212025-04-0145454055210.13284/j.cnki.rddl.202407931001-5221(2025)04-0540-13Characteristics and Risk Assessment of Group Landslide-Debris Flow Disaster Chain in the Hilly Mountains of South China: A Case Study of the Magui River Basin in Gaozhou, Western GuangdongShen Qiuhua0Wang Jun1Li Hao2Gong Qinghua3Li Nianqin4Li Jingfu5Yuan Shaoxiong6Liu Bowen7Guangdong non-ferrous geological environment center//Guangdong Nonferrous Metals Engineering Investigation Design Institute, Guangzhou 510080,ChinaGuangzhou Institute of Geography, Guangdong Academy of Sciences//Guangdong Open Laboratory of Geospatial Technology and Application//Guangdong Geological Disaster Emergency Technology Research Center, Guangzhou 510070, ChinaGuangzhou Institute of Geography, Guangdong Academy of Sciences//Guangdong Open Laboratory of Geospatial Technology and Application//Guangdong Geological Disaster Emergency Technology Research Center, Guangzhou 510070, ChinaGuangzhou Institute of Geography, Guangdong Academy of Sciences//Guangdong Open Laboratory of Geospatial Technology and Application//Guangdong Geological Disaster Emergency Technology Research Center, Guangzhou 510070, ChinaGuangzhou Institute of Geography, Guangdong Academy of Sciences//Guangdong Open Laboratory of Geospatial Technology and Application//Guangdong Geological Disaster Emergency Technology Research Center, Guangzhou 510070, ChinaGuangdong non-ferrous geological environment center//Guangdong Nonferrous Metals Engineering Investigation Design Institute, Guangzhou 510080,ChinaGuangzhou Institute of Geography, Guangdong Academy of Sciences//Guangdong Open Laboratory of Geospatial Technology and Application//Guangdong Geological Disaster Emergency Technology Research Center, Guangzhou 510070, ChinaGuangzhou Institute of Geography, Guangdong Academy of Sciences//Guangdong Open Laboratory of Geospatial Technology and Application//Guangdong Geological Disaster Emergency Technology Research Center, Guangzhou 510070, ChinaThe current risk assessment of single landslides and debris flow disasters ignores the increasing supply, accumulation, and superposition amplification effects of disasters from top to bottom, resulting in a serious underestimation of the risk of landslide-debris flow disaster chains. This study takes the "2010.9.21" mega-landslide debris flow disaster in the Magui River Basin in Gaozhou, western Guangdong as a case study. A landslide-debris flow disaster chain risk assessment index system, guided by the cumulative amplification effect, was established from the perspective of disaster chain initiation, transmission, and cumulative amplification. A comprehensive index model was used to scientifically evaluate the risk of the disaster chain, and actual investigation results were used for verification. The results are as follows: 1) The landslide-debris flow disaster chain in the Magui River Basin is characterized by multi-ditch collection, high impact force, and major terrain fluctuation. The landslide in the starting area is directly transformed into a debris flow during the instability process and flows into the debris flow branch ditch over a short distance. Several debris-flow branches received landslides along the path, converging into the main ditch. After potential energy accelerates through the circulation area, the flow rushes out of the ditch, leading to a large area of fan-shaped accumulations in the low- and slow-terrain areas, causing serious damage to residential houses and farmland. 2) A total of one small watershed unit carries an extremely high risk, accounting for 2.04% of the total number of small watersheds. The extremely high-risk area covers 3.64 km2, accounting for 2.24% of the total area. It is mainly distributed in a small watershed east of Liutang Village. There were eight small watersheds in high-risk areas, accounting for 16.33% of the total small watershed number. The dangerous area covers an area of 20.50 km2, accounting for 12.62% of the total area. Most watersheds are concentrated in Langlian Village, Shenshui Village, Makeng Village, and northern Longkeng Village in the Middle East region of Liutang Village. The number of small watersheds in the medium-risk area was 18, accounting for 36.73% of all the small watersheds, and the total area covered by dangerous area was 81.22 km2, accounting for approximately 44.90% of the total study area. The medium-risk areas were widely distributed within the scope of the study, especially in the southern part of Longkeng Village, most of the small watersheds of Liutang Village, the southern part of Langlian Village, Magui Village, Chengdong Village, Gancheng Village, the central area of Daxi Village, Houyuan Village, and Shanxin Village. There were 22 small watersheds in the low-risk area, accounting for 48.98% of the total number of small watersheds. The low-risk area covers 57.07 km2, accounting for 35.13% of the total study area. It is mainly distributed in the small watersheds of Shanxin Village, Houyuan Village South, Yadong Village South, and Zhoukeng Village in the northeast; Daxi Village in the west; Hemudong Village in the central region; and Longkeng Village in the south. 3) The evaluation results of this study were verified using actual investigation data, which showed high consistency with field survey results, thereby confirming the credibility of the method employed in this study. The index system and evaluation approach for the risk assessment of mass landslide-debris flow disaster chains proposed in this paper can serve as a reference for risk studies of landslide-debris flow disaster chains in South China and other similar areas.https://www.rddl.com.cn/CN/10.13284/j.cnki.rddl.20240793landslidedebris flowdisaster chainrisk assessmentcumulative amplification effectthe hilly mountains of south china
spellingShingle Shen Qiuhua
Wang Jun
Li Hao
Gong Qinghua
Li Nianqin
Li Jingfu
Yuan Shaoxiong
Liu Bowen
Characteristics and Risk Assessment of Group Landslide-Debris Flow Disaster Chain in the Hilly Mountains of South China: A Case Study of the Magui River Basin in Gaozhou, Western Guangdong
Redai dili
landslide
debris flow
disaster chain
risk assessment
cumulative amplification effect
the hilly mountains of south china
title Characteristics and Risk Assessment of Group Landslide-Debris Flow Disaster Chain in the Hilly Mountains of South China: A Case Study of the Magui River Basin in Gaozhou, Western Guangdong
title_full Characteristics and Risk Assessment of Group Landslide-Debris Flow Disaster Chain in the Hilly Mountains of South China: A Case Study of the Magui River Basin in Gaozhou, Western Guangdong
title_fullStr Characteristics and Risk Assessment of Group Landslide-Debris Flow Disaster Chain in the Hilly Mountains of South China: A Case Study of the Magui River Basin in Gaozhou, Western Guangdong
title_full_unstemmed Characteristics and Risk Assessment of Group Landslide-Debris Flow Disaster Chain in the Hilly Mountains of South China: A Case Study of the Magui River Basin in Gaozhou, Western Guangdong
title_short Characteristics and Risk Assessment of Group Landslide-Debris Flow Disaster Chain in the Hilly Mountains of South China: A Case Study of the Magui River Basin in Gaozhou, Western Guangdong
title_sort characteristics and risk assessment of group landslide debris flow disaster chain in the hilly mountains of south china a case study of the magui river basin in gaozhou western guangdong
topic landslide
debris flow
disaster chain
risk assessment
cumulative amplification effect
the hilly mountains of south china
url https://www.rddl.com.cn/CN/10.13284/j.cnki.rddl.20240793
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