热带地理2025，Vol.45Issue(4)：540-552,13.DOI:10.13284/j.cnki.rddl.20240793
华南丘陵山区群发性滑坡—泥石流灾害链发育特征与危险性评价——以粤西高州马贵河流域为例
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
摘要
Abstract
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.关键词
滑坡/泥石流/灾害链/危险性评估/累计放大效应/华南丘陵山区Key words
landslide/debris flow/disaster chain/risk assessment/cumulative amplification effect/the Hilly Mountains of South China分类
安全科学引用本文复制引用
沈秋华,王钧,黎昊,宫清华,黎念卿,李景富,袁少雄,刘博文..华南丘陵山区群发性滑坡—泥石流灾害链发育特征与危险性评价——以粤西高州马贵河流域为例[J].热带地理,2025,45(4):540-552,13.基金项目
国家自然科学基金项目(42271091) （42271091）
广东省自然科学基金-青年提升项目(2024A1515030114) （2024A1515030114）
