| 摘要: |
| 为研究长江口枯季盐水入侵及北支盐水倒灌特性，于2013年12月及2014年2月两次对长江口南北支分汊口处进行全潮同步水文测验，分析结果表明：受地形地貌因素影响，北支进口盐度比同期南支白茆沙水域的高出一个数量级。水域盐度与径流量大小呈负相关关系，与潮差大小呈正相关关系。径流较小、潮差较大时，北支盐水会发生倒灌。由于下泄径流的顶托，迫使倒灌盐水北偏，使得白茆沙北水道盐度大于南水道。风应力对盐水入侵的影响不可忽视，持续的南风会减弱长江口北支的盐水入侵。在枯季条件下，北支倒灌盐水一般沿白茆沙北水道南侧下泄。大潮时倒灌进入南支的盐水在白茆沙水域有一定时间的滞留，使得白茆沙水域盐度往往会在大潮后的中潮期达到最大。 |
| 关键词: 盐水入侵 枯季 北支 风应力 长江口 |
| DOI： |
| 分类号:X522 |
| 基金项目:中央分成水资源费项目（1261530210283）；国家科技支撑计划项目（2013BAB12B04，2013BAB12B05）；国家自然科学基金面上项目（51479122）；交通运输建设科技项目(2011-328-746-40，2012-329-A06-040) |
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| Analysis of saltwater intrusion into Yangtze estuary during dry seasons of 2013 and 2014 |
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DING Lei1, DOU Xi-ping1, GAO Xiang-yu1, XU Hai-dong2, JIAO Jian1
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1.Key Laboratory of Port, Waterway and Sedimentation Engineering of the Ministry of Transport, Nanjing Hydraulic Research Institute, Nanjing;2.The Survey Bureau of Hydrology and Water Resources of Changjiang Estuary, Changjiang Water Resources Commission, Shanghai
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| Abstract: |
| In order to study the characteristics of saltwater intrusion into the Yangtze (Changjiang) estuary and the saltwater spilling over from the north branch of the Yangtze estuary in dry seasons， two tidal synchronous hydrologic surveys were carried out in the bifurcation of the north branch and the south branch in December 2013 and February 2014. Analyses of the data have given several conclusions. Under the impacts of geomorphology, the salinity in the entrance of the north branch is an order of magnitude higher than that of water in the Baimao shoal. The salinity of water is negatively correlated to the runoff volume, while tidal range is positively related. The saltwater will spill over from the north branch while the runoff volume is relatively small and the tidal range is relatively large. Due to the backwater effects of the runoff, the spilling saltwater is forced to head for the north, so the salinity of the north channel of Baimao shoal is larger than that of the south channel. The wind stress has a significant effect on the salinity intrusion and the continuous south wind can decrease the intensity of the salinity intrusion in the north branch. The saltwater spilling over from the north branch flows on the south side of Baimao shoals north channel, and stays in Baimao shoal for several days during spring tide and the salinity in water around Baimao shoal reaches a maximum value in the moderate tide after the spring tidal. |
| Key words: salinity intrusion dry season north branch wind stress Yangtze estuary |
