中文摘要：

应用改进的长江河口盐水入侵三维数值模式,计算东风西沙水库最长不宜取水天数.利用2007—2008年10个水文站盐度资料对模式进行了验证,计算结果与实测值吻合良好.以径流量特枯的1978—1979年作为水文计算年,考虑三峡工程、南水北调东线工程和沿江引排水对大通实测逐日径流量的修正,并考虑潮汐、风应力和混合等作用,采用2008年实测地形资料,计算得出最长连续不宜取水天数为26 d.这一重要参数已在水库建设中采用,为崇明岛生态岛的建设和淡水资源的保障及安全提供了科技支撑.

英文摘要：

An improved three dimension numerical model of saltwater intrusion in the Changjiang Estuary was applied to this numerical simulation.The model was validated with the salinity observed in 2007—2008 at the 10 hydrological sites,and the results showed that the model calculated salinity are well consistent with the observed ones.We considered the extremely drought year 1978—1979 as a hydrological calculation year,adopted the observed topography in 2008,and considered the effects of tide,wind stress and mixing in the model.The measured daily river discharge at the Datong station was modified by the Three Gorges Project,the eastern water diversion project from the South to the North,and the water intake and drain along the river.The conclusion is that the longest continuous days unsuitable for water intake in the Dongfengxisha reservoir are 26 days.This important parameter has been adopted in the build of the reservoir,providing scientific and technological support for the construct of ecological Chong- ming island and the ensure of freshwater resource safety.