山区河流二维推移质数学模型及应用研究--以望谟河整治工程为例

摘要

In order to utilize rich hydropower resources in southwest mountain area of China and decrease flow with high sand proportion and debris flow disasters caused by flash flood , we should establish suitable two-dimensional bed load mathematical models for rivers in mountain area .On the basis of finite volumetric method , we dispersed common controlling equations in sediment numerical model of two-dimensional flow , dealt with dry land boundary by using frozen method , and established a general two-dimensional bed load mathematical model .Xintun section in Wangmo river located in Guizhou province was taken as an example .We carried out numerical calculation of flow field, exploring scouring and deposition of bed load .Test results showed that , as for water level calculation and ver-ification of scouring and deposition in the river bed , simulated data was in consistent with data from empirical for-mula;after regulation project of the river , most of water levels along the flow direction decreased , except for slight increase in few sections;meanwhile , in the condition of given discharge ,water level after the regulation was smaller than that before the regulation , and sediment deposition into the water flume decreased , which is in favor of river flood control .%为了充分利用我国西南山区丰富的水能资源，同时减少望谟河因山洪引起的高含沙水流洪涝和泥石流灾害，应用二维水流泥沙数学模型常用的控制方程式，采用有限体积法对方程进行离散，并使用“冻结法”对模型中陆地边界进行处理，建立了具有一定通用性的山区河流的二维推移质数学模型。利用建立的模型对贵州省望谟河新屯段进行了流场和推移质冲淤模拟计算，并进行了望谟河整治工程影响分析。结果表明：对于望谟河水位和河床冲淤变形验算，数值模型计算值与经验公式推算变化趋势一致，数值也较为接近；整治工程实施后望谟河沿程的水位绝大部分发生不同程度的降低，仅局部存在微小的抬高；望谟河整治后，同流量下，水位降低，流速归槽泥沙淤积减小，有利于河道防洪。