三峡与南水北调工程对长江口水源地的影响

Numerical study on impact of water regulation of TGP and South-to-North Water Diversion Project on water source area of the Yangtze estuary

利用Delft3D-Flow建立了长江口二维潮流和盐度数学模型,并利用现场实测的水流、盐度数据对模型进行率定验证,较好地模拟了长江口盐水入侵的周期性变化规律。在此基础上,分别将枯水期三峡工程和南水北调工程各调水方案与外海的典型潮波进行组合模拟多种水文条件下的盐度场,并对宝钢水库、陈行水库以及在建的青草沙水库的取水口盐度进行了分析。结果表明:南水北调东线工程的预期最大调水量为1000 m^3/s的调水方案将加剧长江口的盐水入侵,水库取水口附近的盐度变大;三峡工程枯水期下泄流量增加,有利于缓解长江口水源地的盐水入侵。

A two dimensional numerical model is built to simulate the hydrodynamics and salinity about Yangtze estuary by the method of Delft3D-Flow.The model is calibrated and validated through the observed data and the simulation presents a good periodic salinity change.Further- more,combined simtdations for the estuary salinity field under multiple hydrologic conditions of the different regulation schemes of Three Gorges Project and South-to-North Water Diversion Project in dry.season as well as variation of tidal ranges in the outer sea are carried out.The salinity at water intake sites of three reservoirs,including Baogang,Chengxing,and Qingcaosha(under construction),is analyzed.The computed results show that the maximum water diversion scheme of 1 000 m3/s of South-to-North Water Diversion will aggravate saline water intrusion of Yangtze es- tuary and the salinity at water intake sites will increase,the increased discharge of TGP in dry season will alleviate saline water intrusion.