牛眠沟流域泥石流形成条件、发展趋势及其防治探讨

DISCUSSION ON GENESIS AND DEVELOPMENT TREND CONTROL ENGINEERING OF DEBRIS FLOW IN NIUMIANGOU VALLEY

汶川地震使牛眠沟流域变成了一个多泥石流灾害的区域,到目前为止,已经发生7次大规模泥石流灾害。经研究,该流域诱发泥石流灾害的3个基本条件非常发育,而目前正处于发展阶段,在震后5～10年内的雨季,极易发生危害性较大、冲击力较强的大规模降雨型泥石流。如果考虑直接利用主沟内沉积的泥石流堆积物,在主沟堆积区的中上游左右两侧修建约为沟宽一半的交替式拦挡土石坝、在中下游修建与沟宽大致相等的拦挡土石坝及在相邻两坝间修建与沟向相对且具有一定坡度斜坡的土木防治工程,可实现消能与耗能双重目的。

After Wenchuan earthquake,Niumiangou valley becomes an area with dense and frequent debris flow disasters;so far,seven large-scale debris flows occurred.In this valley there are three basic conditions making debris flow well develop, and so it is in a developing stage now.Thus the large-scale rainfall induced debris flow disasters,with large damage and stronger wallop,will easily occur in the 5-10 year after earthquake.If considering to use directly the debris flow deposit in the main gully of Niumiangou valley,to construct civil control engineering such as alternate landslide dams from earth and rock with about half of main gully width in the left and right sides of upper and middle of the accumulation area,landslide dams from earth and rock with approximately equal to main gully width in middle and lower of the accumulation area and slope with certain gradient and relative to gully orientation between two adjacent dam,then the dual-purpose of energy dissipation and consumption can be achieved.