优化小浪底水库调水调沙运用方式的建议

Suggestion on Optimizing Flow and Sediment Regulations as the Operational Methods of the Xiaolangdi Reservoir

对小浪底水库运用以来黄河下游河道冲刷情况及调水调沙运用存在的主要问题进行了分析,并对调水造峰期间下游河床冲淤特性进行了研究。结果表明:经过小浪底水库10 a调水造峰与清水冲刷,黄河下游河道主槽排洪能力已经得到有效恢复,为利用洪水排沙创造了有利条件;连续10次调水调沙,冲刷效率逐步降低,且存在排沙期下游河道淤积、流量沿程增大等问题。洪水具有"涨冲落淤"的输沙特性,因此小浪底水库应改变目前落水时加沙的调水调沙运用方式,尽量在洪水涨水期集中排沙出库,一般情况不要再放平头峰,以提高下游河道的输沙效率。

This paper analyzed the scour condition of the lower Yellow River channel after the operations of Xiaolangdi Reservoir and major problems of flow and sediment regulations.It also researched on the scour and deposition properties of the river bed of the lower reaches during the man-made flood peak.The results show that,after the man-made flood peak and clear water scours for 10 years,the flood discharge capacity of the lower reaches has been effectively restored,which creates favorable condition for transporting sediment by flood.Consecutive flow and sediment regulations for 10 times,have resulted in less scour efficiency,and new situations occurred like deposition in the lower reaches during sediment discharge,as well as the increase of discharge along the main stem.The flood has the characteristics of ＂scour in rising and deposit in falling＂,so it is suggested that the Xiaolangdi Reservoir should change its operational method of discharging sediment during falling period.Sediment should be discharged during the rising period of the flood hydrograph and a flood peak that with a gentle hydrograph and longer duration shouldn＇t be created.This way,the efficiency of sediment transport in the lower reaches can be increased.