卵砾石河流推移质输沙率的模拟计算方法

Modeling Method of Bed Load Transport Rate in Rivers with Gravel and Cobble Bed

根据山区和丘陵地区卵砾石河流的情况，提出对梅叶－彼得推移质输沙公式进行修正，使用式（８）的泥沙起动切应力公式，在分析的基础上提出粗细泥沙颗粒的隐曝系数公式和考虑水流床面切应力随机分布的计算方法，用以估计这类河流的推移质输沙率．经长江上水文站的实测资料检验与河道泥沙数模的应用，能满足工程计算的需要，取得较好效果，可作为这类河流中计算推移质输沙率的参考．

Meyer Peter & Muller bed load formula is a famous one, which was used in many areas over world for almost a half century. Some modifications are proposed for rivers with gravel and cobble bed based on the conditions in mountain region and hilly land. A new formula to calculate grain threshold shear stress is used. Nonuniform bed materials and their mutual influences are accounted by a hiding protruding coefficient. A low shear stress distribution function is introduced for reflecting the flow fluctuation, non uniformity and instablility. The bed load rate and grain composition is verified by the data taken from hydrologic stations on the Yangtze River. The modified formula is successfull used in the mathematical river sediment model of the upper river and downstream of the Three Gorges Reservoir.