宕昌县大地沟泥石流特征及其防治对策

The Features and Prevention of Debris Flow in Dadigou,Dangchang County

阐述了大地沟泥石流的形成条件、发育机制及特征以及灾害的严重性和治理的必要性.提出了以拦挡工程为主,结合泥石流停淤、排导和生物措施综合治理方案的同时,主体工程要追求安全与经济相结合的断面优化形式.结果表明,工程实施后综合效益明显,泥石流变成夹沙洪水,对县城的危害基本消除.并根据工程运行情况,就工程本身的不足进行说明并提出改进措施.

Dadigou is one of the famous debris flow disastrous gully in Gansu province.There are 571×104 m3 loose solids in the gully.The formation condition of debris flow is extremely advantageous.In order to protect the farmland,villages,towns,roads and Dangchang city in upper reaches of Minjiang River,the seriousness of debris flow disaster and the necessity of its prevention are analyzed based on the formation mechanism and the features of debris flow in Dadigou.A comprehensive controlling program is put forward,which is to take the blocked works as the dominant measure,along with debris flow silting ground,draining channel,barrage and biological measures.When the project is completed,the comprehensive benefits will be feet per year.Now the debris flow has changed to usual flood flow.So its threat to Dangchang County has been eliminated.Through operation of the works on the project itself,an in-depth study is concerned with engineering deficiencies.At last,the characteristics of the debris flow is analyzed;the project evaluation is done,focusing on the design of the control projects and their actual efficacies;the shortcomings of these projects are pointed out and optimizing methods are put forward.On the basis of the analysis,some advices are given to the prevention and control.This will provide reference for rational designs.