【摘要】 先家庙沟为雅砻江下游支流九龙河右岸的一条支沟,位于四川省甘孜州九龙县,2013年7月17日暴发较大规模泥石流。为了研究泥石流的活动特征和提出适宜的泥石流减灾防灾对策,在野外调查和实地勘测的基础上,分析了该泥石流沟的形成环境、活动特征等,探讨了工程实施的背景条件和村镇泥石流的防治思路。研究表明,先家庙沟受汶川8.0级地震扰动,在主沟形成区2 700~3 100 m段产生崩塌滑坡,形成集中物源,由震前的山洪沟转化为泥石流沟,活动频率增加;先家庙沟具有"陡—缓—陡—缓"的纵坡型式,由于流通段陡崖地貌的存在,流速增大约3倍,冲击力增大约5倍,泥石流冲出流通段后流速较大,对沟口省道S215和居民房屋造成威胁,泥石流成灾能力强;针对流域地形特征和泥石流活动特征,在坝高较高的拦挡坝工程和排导工程实施受限的情况,提出"固源+停淤+排水"总体思路,可以为其他类似条件的泥石流治理工程提供防治思路。更多还原

【Abstract】 Xianjiamiao Gully,located in Jiulong Town,is one of the first tributaries of the Jiulong River of the Yalong River system. The debris flow occurred on 17 th,July,2013. To study the debris flow hazards characteristics and propose feasible engineering mitigation measures,the formation condition and the unique feature of the gully are analyzed based on the field survey,and the background condition of engineering mitigation and the rural debris flow mitigation strategy are discussed. Results indicate that the debris flow in the gully occurred instead of a mountain torrent because the Wenchuan 8. 0Ms earthquake destabilized the slope of the gully,leading to a leap of solid materials in the initiation zone at the elevation from 2 700 meters to 3 100 meters. Xianjiamiao gully with steep-gentle-steep-gentle gradient in longitudinal slope and a scrap in the transportation zone which caused the velocity increased three-fold and the impact force five-fold. The potential risk is still high since the debris flow could do damage to the S215 and the inhabits by the high velocity flow. The mitigation strategy of "stabilization + deposition +drainage"are proposed after the study on watershed topography and debris flow characteristics and taking the limitation of high check dam and drainage channel into consideration. The mitigation strategy of Xianjiamiao Gully could provide reference for the other gullies with similar situation.更多还原