涪江源区韩家沟泥石流防治工程改进前后危险性分析  

Debris flow hazard analysis before and after improvement of Hanjia gully control engineering at the source area of the Fujiang River

作　　者：唐海兵 吴建军 张春山[1,2,3] 杨为民 渠敬凯[1,2,4] 马思琦 徐传成 TANG Haibing;WU Jianjun;ZHANG Chunshan;YANG Weimin;QU Jingkai;MA Siqi;XU Chuancheng(Institute of Geomechanics,Chinese Academy of Geological Sciences,Beijing 100081,China;Key Laboratory of Active Tectonics and Geological Safety,Ministry of Natural Resources,Beijing 100081,China;Research Center of Neotectonism and Crustal Stability,China Geological Survey,Beijing 100081,China;China University of Geosciences,Beijing 100083,China;The Geological Prospecting Team of Sichuan Geological&Mineral Bureau,Chengdu 610070,Sichuan,China)

机构地区：[1]中国地质科学院地质力学研究所,北京100081 [2]自然资源部活动构造与地质安全重点实验室,北京100081 [3]中国地质调查局新构造与地壳稳定性研究中心,北京100081 [4]中国地质大学(北京),北京100083 [5]四川省地质矿产勘查开发局物探队,四川成都610070

出　　处：《地质力学学报》2024年第4期659-672,共14页Journal of Geomechanics

基　　金：科技部基地与人才项目(2019QZKK0902)。

摘　　要：为了降低涪江源区左岸韩家沟泥石流的危害,文章采用遥感解译、野外调查、FLO-2D数值模拟等手段,查清了韩家沟泥石流特征及其防治现状,认为现有防治工程不能满足防灾需求,并据此提出改进的防治工程,对不同降雨频率下防治工程改进前后的泥石流危险性进行了研究,并分析改进防治工程的有效性。结果表明:韩家沟位于“8·8”九寨沟地震扰动区,震后泥石流物源丰富,导致每逢强降雨时泥石流频发。在10年一遇降雨频率下,丰河村及平松路均处于低危险区,现有防治工程可有效防治泥石流灾害;在50年一遇降雨频率下,丰河村处于泥石流高危险区,泥石流冲出排导槽,冲毁平松路,现有防治工程不能满足要求。采用多级拦挡坝、排导槽截弯取直等改进的防治工程后,可有效预防泥石流对沟口下方承灾体的损害,泥石流堆积方量减少50.2%,堆积面积减少86%,高危险区均位于排导槽内,治理效果显著。[Objective]Debris flow from the Hanjia gully develops on the left bank of the source area of the Fujiang River,Fenghe Village,Xiaohe Town,Songpan County,China.In recent years,debris flows have occurred frequently,and the largest debris flow occurred in August 2022,which seriously threatened the lives and properties of villagers in the Hanjia gully.Existing prevention and control engineering methods have decreased in effectiveness or even become ineffective.Currently,researchers have set a variety of extreme rainfall conditions and used FLO-2D to analyze the hazards of debris flow,based on which the governance effect of debris flow prevention and control engineering can be evaluated.However,there are few reports on how to improve the prevention and control engineering and evaluate the effect of the improved prevention and control engineering when the existing prevention and control engineering is ineffective.[Methods]To reduce damage to the Hanjia gully,the characteristics as well as prevention and control status of the debris flow in/from this gully were determined using remote sensing interpretation,field investigation,and FLO-2D numerical simulation;subsequently,improved prevention and control engineering was proposed.The hazard of debris flow before and after the improvements in prevention and control engineering under different rainfall frequencies were studied to analyze the effectiveness of the improved prevention and control engineering.[Results]The results show that the Hanjia gully is located in the"8.8"Jiuzhaigou earthquake disturbance area,the static reserves of post-earthquake landslides and collapses are about 49.79×10^(4) m3,and the debris flow sources are abundant,which leads to frequent debris flow during heavy rainfall.The high-hazard area is concentrated in the No.1 retaining dam,and Fenghe Village and Pingsong Highway are in the low-hazard area under a rainfall event occurring every 10 years,and the existing prevention and control engineering can effectively prevent the debris flow disaster.Un

关 键 词：工程地质 泥石流 改进防治工程 治理效果 降雨 地质灾害 

分 类 号：P694[天文地球—地质学] P642.5