Department of Hyraulic Engineering, Tsinghua University, Beijing 100084, China.
China Institute of Water Resources and Hydropower Research, Beijing 100038, China.
Int J Environ Res Public Health. 2019 Jan 4;16(1):118. doi: 10.3390/ijerph16010118.
More attention has been paid to saltwater-intrusion-related problems in recent years. In this research study, a saltwater intrusion function in the Yangtze River Estuary (YRE) was constructed based on the theory of the interactions between energy accumulation and impedance. A MIKE21 model was used to simulate the hydrodynamics of the YRE. Then, through the analysis of the relationships between the river discharge conditions, tidal ranges, and saltwater intrusion, it was determined that, under certain river discharge conditions, the tidal ranges and salinity levels at the stations in the southern branch (SB) of the YRE conformed to S-shaped curve characteristics. Also, the tidal ranges and salinity excessive area rate (SEAR) displayed similar characteristics. Furthermore, the river discharge conditions were also found to match the S-curve characteristics between the two aforementioned relationship features. Therefore, the saltwater intrusion function of the YRE was constructed based on the previously mentioned development rules. Also, the applied quantification methods were elaborated, and the values of the parameters were determined. As a result, the critical river discharge (more than 10,000 m³/s) was obtained, which could withstand large-scale saltwater intrusions. When the river discharge was greater than 30,000 m³/s, the area was considered to be basically without salt water intrusions, and the estuarine ecology was in an optimal state. The saltwater intrusion losses from 2005 to 2015 are also calculated. These findings have important reference value for water dispatching of the YRE in the dry season.
近年来，人们越来越关注海水入侵相关问题。本研究基于能量积累与阻抗相互作用理论，构建了长江河口盐水入侵函数。利用 MIKE21 模型模拟长江口水动力，通过河川径流量条件、潮差与盐水入侵的关系分析，确定在一定河川径流量条件下，长江口南支（SB）各站位的潮差和盐度符合 S 型曲线特征，且潮差和盐度超量面积率（SEAR）具有相似特征，河川径流量条件也符合两者关系特征的 S 型曲线特征。在此基础上，构建了长江河口盐水入侵函数，并阐述了应用的量化方法和参数取值，得到了可抵御大规模盐水入侵的临界河川径流量（大于 10000m³/s），当河川径流量大于 30000m³/s 时，可认为该区域基本无盐水入侵，河口生态处于最佳状态。并计算了 2005-2015 年盐水入侵损失量。本研究结果可为长江口枯季水量调度提供重要参考。
