中文摘要：

“5·12”汶川特大地震后,龙溪、白沙河流域泥石流灾害频发,为更好地防治这两个流域的泥石流灾害,评估已有泥石流防治工程的治理效果具有重要意义。三合场沟位于地震重灾区四川省都江堰市虹口乡,地震引发沟内山体发生了大规模的滑坡和崩塌,为泥石流的发育提供了丰富的物质基础。在对三合场泥石流沟流域现场调查及对该沟“稳＋拦”泥石流灾害治理模式研究的基础上,分析了该沟防治工程的治理效果。结果表明：该工程采取的以拦挡为主的治理措施并未取得预期的防治效果和使用寿命。针对防治工程的治理现状和震后三合场泥石流沟的特点,指出了其存在的问题,并建议在该流域治理泥石流灾害时采取以排导工程为主,生物措施与工程措施相结合的防治工程体系。

英文摘要：

Since the ＂5.12＂ Wenchuan earthquake, the debris flows occurred frequently in Baisha River basin and Longxi River basin. In order to better prevent and control debris flow in these two basins, it is of great significance to assess the effect of the existing debris flow control projects. Sanheehang gully is located in Hongkou town of Dujiangyan city, a severely afflicted area of Whenchuan earthquake in Sichuan province. The earthquake induced large scale collapses and landslides that provided plenty of loose solid material for debris flow. Based on the field survey of Sanhechang gully and the study on the debris flow control mode of ＂stabilizing and impounding＂, the control effect was analyzed. The result shows that the control measures dominated by bloc- king fail to achieve expected effect and service life. According to the current situation of the project and the characteristics of the gully, we point out the problems existing in this project. It is suggested that the prevention and control engineering system should focus on drainage and combined biological and engineering measures.