| 摘要: |
| 上海市饮用水的80%来自长江口三大水源地——陈行水库、青草沙水库和东风西沙水库。枯季盐水入侵一直是长江口水源地安全面临的最大威胁。作为河口区域的主要动力，有必要进一步研究径流和潮汐对长江口水源地盐水入侵的影响。通过建立长江口平面二维潮流盐度数学模型，对长江口盐水入侵进行模拟，分析了水源地取水口盐度过程与潮位过程的关系，探讨了北支盐水倒灌对水源地的影响。研究结果表明：三大水源地因位置不同，盐度过程线特征也不相同。水源地取水口盐度过程线与潮位过程线的关系可作为受北支倒灌盐水和正面入侵盐水影响程度的重要依据。北支盐水倒灌发生时，东风西沙水库、陈行水库、青草沙水库水源地分别在大潮、中潮及小潮时受倒灌盐水影响最为严重。随着径流增大，水源地受盐水入侵影响的时间会提前，但是盐度则随径流的增大而减弱。 |
| 关键词: 盐水入侵 长江口 水源地 径流 潮汐 北支盐水倒灌 |
| DOI： |
| 分类号:P731.2; P343.5 |
| 基金项目:国家重点研发计划资助项目（2017YFC0405400， 2017YFC0405406）； 中央分成水资源费项目（1261530210283）； 南京水利科学研究院基本科研业务费专项资金资助项目（Y217010） |
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| Response of salinity at water source intakes to runoff and tidal dynamics of Yangtze River estuary |
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DING Lei1, CHEN Liming1, GAO Xiangyu1, JIAO Jian1, HU Jing2
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1.Key Laboratory of Port, Waterway and Sedimentation Engineering of the Ministry of Transport, State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing;2.Nanjing Water Planning and Designing Institute Co., Ltd., Nanjing
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| Abstract: |
| The Chenhang reservoir, Qingcaosha reservoir and Dongfengxisha reservoir are the three major water sources at the Yangtze River estuary. 80% of the Shanghai’s drinking water comes from the three major water sources. The intrusion of the salt water in the low flow seasons is always a great threat to the water source safety at the Yangtze River estuary. As the two main dynamics forces of the estuarine area, it is necessary to further study the influences of runoff and tide on the salt water intrusion to the water sources in the Yangtze River estuary. A two-dimensional salt transport numerical model is developed to simulate the flow-salt dynamic processes. And the relationship between the salinity hydrograph and the tidal line can be taken as an important basis for analyzing the influences of the northern branch on the water sources. The analyses of the model results show that the characteristics of the salinity duration lines are different because of the different locations of the three water sources. The relationship between the salinity and water level duration can indicate the degree affected by saltwater spilling over from the north branch and saltwater directly from the sea. While the salt water spilling over from the north branch occurs, the water sources of the Dongfengxisha reservoir, the Chenhang reservoir and the Qingcaosha reservoir are most seriously affected by the brine in the spring, middle and lower tides respectively. With the increase of runoff volume， the time affected by saltwater intrusion will advance, but the salinity will decrease with the increase of the runoff. |
| Key words: salinity intrusion the Yangtze estuary water source runoff tide saltwater spilling over from the north branch |
