长江口水沙变化与趋势预测

Review of hydro-sediment change and tendency in Yangtze estuary

随着长江流域水土保持、上游水库拦蓄调节、沿江用水增加及气候变化,进入长江口的水沙通量发生改变,入海泥沙量锐减。此外,长江口相继实施了深水航道治理、青草沙水源地、浅滩圈围等大型工程。因此,需要针对长江口水沙变化开展相关研究。对长江口陆相和海相水沙变化规律及趋势、河床容积与泥沙收支变化以及整治工程下分汊河口演变预测等进行了概述,预测了今后10~50年大通站流量、含沙量、输沙量变化以及南北槽的演变趋势,为进一步研究变化条件下的长江口重大工程安全提供基础条件。

With the conservation of water and soil in the Yangtze River basin,the adjustment of upstream reservoirs,the increase of water use,and the change of climate,the volume of water and sediment flux into the Yangtze River estuary has changed,therefore the amount of sediment into the sea has decreased sharply.In addition,the Yangtze River estuary has successively undergone large-scale projects such as Deepwater Channel Regulation Project,Qingcaosha Water Source Project,and the reclamation of shoals.Thus,it is necessary to implement relevant researches on the variation of water and sediment in the Yangtze River estuary.This paper summarizes the variation law and trend of landward and seaward water and sediment movement in the Yangtze River estuary,the changes of riverbed volume and sediment budget,and the prediction of the evolution of the bifurcated estuary under the influence of the regulation project.The changes of discharge,sediment concentration,sediment transport and the evolution trend of the south-north passage of Datong station in the next 10-50 years are predicted,which provides basic conditions for further studies of the major projects′safety in the Yangtze estuary.