西柳沟流域近期水沙关系变化特征分析

Characteristics of the Recent Change of Relationship Between Runoff and Sediment in Xiliugou Watershed

根据1960—2010年实测水文资料,对黄河内蒙古段西柳沟流域近期水沙关系的变化特征进行了分析。结果表明:1990—2010年与1960—1989年相比,流域年降水量增大,但暴雨有所减少;来水来沙具有水少沙多、年际变化大、年内分配极度不均等特点;流域最大1 d降雨对产流产沙的影响很大,洪水期降雨产洪变化率指数为0.525 7~2.683 8,降雨产沙变化率指数为0.613 6~2.136 3;流域高含沙水流的侵蚀产沙作用非常强烈,洪水泥沙关系式的幂指数约为1.0,场次洪水多年平均含沙量为612.6 kg/m^3。同时,给出了西柳沟流域形成沙坝淤堵黄河干流的暴雨洪水泥沙阈值。

According to the hydrological data from 1960 to 2010, the characteristics of water and sediment relations in the near future were analyzed on Xiliugou in Inner Mongolia section of the Yellow River.Comparing the periods of 1990-2010 and 1960-1989, the total annual precipitation of watershed increased, but the storm decreased.The characteristics of runoff and sediment were less runoff and more sediment, great inter-annual variation and extreme uneven intra-annual distribution.The maximum 1 day rainfall has great influence to the runoff and sediment, the rainfall flood change rate index is 0.525 7-2.683 8 in flood period, the precipitation and sediment change rate index is 0.613 6-2.136 3.Erosion effect of hyper concentrated flow is very strong, flood and sediment exponent is about 1.0, the flood of mean annual sediment volume is 612.6 kg/m3 .At the same time, it gives the threshold values of rainstorm, flood and sediment of formed sand dam in the Xiliugou watershed.