降雨-波浪-水位对库岸崩滑泥沙空间分布影响

Effects of rainfall,wave and water level on spatial distribution of landslide sediment from reservoir bank

库岸崩滑对库区含沙量有显著影响,掌握崩滑泥沙与水文因素的关系有助于分析库区泥沙的淤积过程和输移规律.通过降雨-波浪-水位多因素耦合模型试验分析了崩滑泥沙在不同水文因素作用下的空间分布规律.结果表明,降雨能减弱含沙量的变化幅度,促使悬移质泥沙颗粒细化.降雨后含沙量平均变异系数降幅为22%,极细砂粒含量降幅为53%.波浪可加大离岸方向库区含沙量,同时降低此方向含沙量变异系数.波浪作用下离岸方向的平均含沙量增幅为78%,含沙量平均变异系数降幅为67%.水位升高促使离岸方向和水深方向的含沙量降低,悬移质泥沙颗粒粗化.离岸方向和水深方向的平均含沙量在水位升高时降幅分别为14%和20%,极细砂粒含量增幅为15%.

The reservoir bank landslide has significant influences on the sediment concentration in the reservoir area.Mastering the relationship between landslide sediment and hydrological factors is helpful for analyzing the deposition process and transport law of sediment in the reservoir area.The spatial distribution law of landslide sediment under different hydrological factors is analyzed through a multi-factor coupling model experiment of rainfall,wave and water level.The results show that rainfall can reduce the amplitude of changes in sediment concentration and promote the refinement of suspended sediment particles.After rainfall,the average coefficient of variation of sediment concentration decreases by 22%,and the fine sand concentration decreases by 53%.Waves can increase the sediment concentration of the reservoir area in the offshore direction,while reducing the coefficient of variation of sediment concentration in this direction.The average sediment concentration in the offshore direction increases by 78%under wave action,and the average coefficient of variation of sediment concentration decreases by 67%.The increase in water level leads to a decrease in sediment concentration in both offshore and water depth directions,resulting in coarsening of suspended sediment particles.After the water level rises,the average sediment concentration in the offshore and water depth directions decreases by 14%and 20%respectively,and the fine sand concentration increases by 15%.