不同频率洪水作用下闽江下游采砂规划对河道演变的影响

Influence of sand excavation planning on river channel evolution in lower Minjiang River under different frequencies of floods

由于闽江上游河流梯级开发电站,使泥沙的运动规律及水力条件发生改变,河道采砂规划使河床下切加剧。本文在分析闽江下游河道洪水、泥沙补给及采砂规划的基础上,对闽江下游河道在遭遇到5年一遇、20年一遇、50年一遇以及100年一遇4种不同频率洪水时,河道规划采砂前后河床断面的冲淤变化进行影响分析,其结果基本揭示了不同频率洪水作用下闽江下游采砂规划对河道演变的规律,结论可为下一阶段闽江下游采砂规划提供参考。

The cascade development of power stations in the upper reaches of Minjiang River has changed the law of sediment movement and hydraulic conditions,and the river bed undercutting has intensified due to the planning of sediment collection.Based on the analysis of flood,sediment supply and sediment collection planning in the lower reaches of Minjiang River,this paper analyzes the impact of river bed section scouring and silting changes before and after sediment collection planning in the lower reaches of Minjiang River when the lower reaches of Minjiang River encounter 4 kinds of floods of different frequencies,such as:5-year,20-year,50-year and 100-year.The results basically reveal the law of sediment collection planning in the lower reaches of Minjiang River on river course evolution under the action of floods of different frequencies and provide data support for sediment collection planning in the lower reaches of Minjiang River.