中文摘要：

汶川地震诱发的大量崩塌和滑坡不仅直接为泥石流活动提供松散固体物质,还可能造成沟道堵塞。沟道内的堵塞坝虽然不像主河道上的堰塞湖那样造成大范围灾害,但溃决后却会引发大规模泥石流,给人民生命财产和基础设施等造成严重危害。以四川省安县高川乡甘沟为例,说明其造成泥石流的危害特征及防治对策。通过对甘沟自然环境背景条件的分析,发现甘沟具备泥石流暴发的地形地貌和降水条件;流域内地震诱发的崩滑体不仅为泥石流的形成提供丰富的松散固体物质,还造成沟道堵塞,形成堵溃型泥石流。甘沟已建的排导槽存在过流能力不够、槽底和侧墙已基本被破坏、弯道处未考虑超高、沟内未布置拦挡工程等问题。目前沟内由于松散固体物质充足,在一定的降水条件下,仍会再次暴发泥石流。针对甘沟的具体情况,提出了修建拦挡、重建排导槽并结合预警预报措施的防治对策,并对重建排导槽的过流断面进行了优化设计。

英文摘要：

A large number of landslides,induced by the Wenchuan Earthquake,directly provide loose materials for subsequent debris flows,but also may cause channel blockage.Channel blockage,as contrasted with river blockage,may not cause widespread damages,but it will transform into large-scale debris flows and cause serious harm to people＇s lives and property and infrastructure.In this paper,taking Gangou gully of Anxian County in Sichuan Province of China as example,we studied the debris flow characteristics and put forward the control debris flow measures.Based on analysis of the natural environment conditions in the gully,we found that its topography was prone to form debris flows.According to the remote sensing interpretation,there was a big landslide,approximately 0.45 million m3 in volume,induced by the earthquake,blocking the channel and forming a landslide dam.It was the failure of the dam that formed large-scale debris flows and caused serious damages to local people.It was also found that the drainage canal had no enough flow capacity and the canal basement and side walls had been destroyed and the excess-height in bend of the drainage canal had not been taken into account.Additionally,there was no debris dam and check dam in the gully.Unfortunately,under the condition of rainfall,debris flows will occur again due to enough loose solid materials in the gully.To solve these problems,the countermeasures of building check dams,heightening drainage canal,warning and forecasting were put forward in this paper.Especially,we considered the optimal cross-section characteristics of debris flow drainage canal in the gully.