上游径流变化对长江澄通河段汊道分流比的影响  

Impacts of upstream discharge changes on branch discharge ratio of Chengtong reach of Yangtze River

作　　者：姜宁林[1] 张长宽[1] 陈永平[1,2] 

机构地区：[1]河海大学港口海岸与近海工程学院,江苏南京210098 [2]河海大学水文水资源与水利科学国家重点实验室,江苏南京210098

出　　处：《人民长江》2012年第23期33-36,42,共5页Yangtze River

基　　金：国家重点基础研究发展计划"973"课题(2010CB429001);国家自然科学基金面上项目(51179067)

摘　　要：通过设定上、下游水位边界条件,利用平面二维潮流数学模型模拟了不同径流条件下长江澄通河段涨、落潮过程,分析了其中福姜沙、如皋沙和通州沙河段分汊河道分流比的变化情况。结果表明:随着上游来流量的增加,福姜沙和如皋沙河段主汊分流比先减小后有所增大,而通州沙河段主汊分流比不断减小。分析上游来流变化对各主要汊道演变的影响表明,上游径流总量的减少使福姜沙和如皋沙主汊分流比减少,不利于河段主槽的发育;在上游水利枢纽工程"削峰"的影响下,河段各主汊的分流比均有一定程度的增加,使主汊更容易得到维护和发展。A two dimensional numerical tidal model is established to simulate the tidal process of the Chengtong reach under different upstream river discharges.The variations of branch discharge ratio of Fujiangsha,Rugaosha and Tongzhousha due to the changes of upstream river discharge are analyzed.The result shows that with the increase of upperstream discharge,the discharge ratio in the main branch of Fujiangsha reach and Rugaosha reach decrease at first and increases later;however,the discharge ratio in the main branch of Tongzhousha reach always decreases.It is shown that the discharge ratio of the main channel at Fujiangsha reach and Rugaosha reach decreases with the decrease of upstream river discharge,which is negative to the development of the main channel.However,due to the 'flood peak reducing' effect of large scale water conservancy projects,the discharge ratio of main branches increases in general,which is positive to the maintenance and development of main branch.

关 键 词：分流比 汊道演变 径流变化 澄通河段 长江口 

分 类 号：TV121[水利工程—水文学及水资源]