中低山台风暴雨型泥石流形成机制和动力特征——以江西德安杜家沟泥石流为例  

Formation Mechanism and Dynamic Characteristics of Typhoon Rainstorm Debris Flow in Middle and Low Mountains——A Case at Dujia Gully, Dean County, Jiangxi Province

作　　者：甘建军[1] 储小东 GAN Jianjun;CHU Xiaodong(Jiangxi Engineering Research Center of Water Engineering Safety and Resources Efficient Utilization,Nanchang Institute of Technology,Nanchang 330099,China;Jiangxi Geological Environment Monitoring Station,Nanchang 330099,China)

机构地区：[1]南昌工程学院江西省水工程安全与资源高效利用工程研究中心,江西南昌330099 [2]江西省地质环境监测总站,江西南昌330099

出　　处：《灾害学》2020年第1期150-155,共6页Journal of Catastrophology

基　　金：江西省水工程安全与资源利用工程研究中心开放基金项目(OF201603);国家自然科学基金项目(51869012;41641023);江西省教育厅科技研究项目(GJJ151124);江西省科技厅第一批科技计划项目(20161BBG70051;20171BBG70046)

摘　　要：受台风"麦德姆"登陆影响,江西省德安县博阳河流域曾于2014年7月24日爆发群发性泥石流,该次泥石流物源类型多样、地质条件复杂,对沟口杜家沟及下游居民的生命财产安全产生了巨大威胁。通过野外调查及室内试验,分析本次泥石流的发育条件和形成机理,利用极限平衡法计算了泥石流的稳定性,提出了治理的方法和对策。研究表明:该次泥石流是在强降雨诱发下,以中上游沟道松散物为启动点、沿程崩滑、侵蚀、揭底、堵塞、溃决,是一场由台风暴雨形成的突发灾害。影响泥石流形成的主要因素是强降雨、丰富的松散物源和陡峻的地貌;泥石流形成过程可分为强降雨、崩滑侵蚀、堰塞溃决三个阶段。参与杜家泥石流启动汇集的物质来源主要为崩滑物源和沟道物源,其中,沟道崩滑量占总量的85%,沟道物源补给以沟道松散物为主,占总量的15%。杜家沟泥石流的成灾模式类型多样,表现为撞击冲毁、堵塞沟道、威胁下游。该泥石流具有低频、灾害链效应。Due to the impact of typhoon "Matmo" landfall, a catastrophically debris flow occurred in Dujiagou, De’an county, Jiangxi province on July 24, 2014. The debris flow sources were diverse and the geological conditions were complex, which posed a great threat to the life and property safety of residents in Dujia gully and downstream. Through field investigation and laboratory test, the development condition and formation mechanism of debris flow were analyzed, the stability of debris flow was calculated by limit equilibrium method, and the control methods and countermeasures were put forward. The results show that the debris flow was a sudden disaster caused by typhoon and rainstorm, which is induced by heavy rainfall and starts from loose material in the middle and upper reaches of the gully. The formation factors of debris flow mainly include heavy rainfall, abundant loose source and steep landform. The formation process is divided into heavy rainfall, landslide erosion and dam break. The material sources involved in the initial collection of mud-rock flow in Dujia are avalanche material source and channel material source, among which, the avalanche material source in gully accounts for 85% of the total amount, and the source material supply in gully is mainly loose material in gully, accounting for 15% of the total amount. The types of debris flow in Dujia gully were various, such as impact, blocking gullies and threatening downstream. The debris flow hasa low frequency and disaster chain effect.

关 键 词：泥石流灾害 形成机制 台风 杜家 动力特征 

分 类 号：P642[天文地球—工程地质学] X43[天文地球—地质矿产勘探]