摘要
为探析潮汐对河口相邻含水层咸水入侵的影响机制,在考虑了潮汐作用下的水位和盐分沿河道变化的基础上,构建了平行于河流的二维潮汐河口河流-含水层瞬态全耦合数值模型,分析了潮汐作用下河流与含水层中流场及盐分分布,并与无潮汐条件下的分布进行了对比。结果表明:潮汐促使海水通过河口迅速入侵河道上游,进而入渗相邻浅层含水层,形成盐指及局部环流,致使相邻浅层含水层大范围咸化,咸化程度和范围显著大于海岸带含水层海水入侵及无潮汐条件下对应工况;单周期内,含水层中的咸水入侵程度与范围随潮汐波动,在落潮中期达到最强,相较潮汐水位变化具有滞后性;入渗盐分部分在相邻浅层含水层中积累并向深层含水层扩散,部分随内陆地下水排泄至河流,继而经河道内陆来水冲刷至海洋。
To explore the influence mechanism of tides on the intrusion of saline water into adjacent aquifers in estuaries,a two-dimensional transient fully coupled numerical model of river-aquifer parallel to the river was established based on the consideration of the variation of water level and salinity along the river under the action of tides.The flow field and salinity distribution in the river and aquifer under the action of tides were analyzed and compared with those under the condition without tides.The results show that tides promote the rapid intrusion of seawater into the upstream of the river through the estuary and then infiltrate into the adjacent shallow aquifer,forming salt fingers and local circulation,resulting in a large-scale salinization of the adjacent shallow aquifer.Compared with the seawater intrusion in coastal aquifers and the corresponding conditions without tides,the salinization degree and range are significantly increased.Within a single tidal cycle,the degree and range of saline water intrusion in the aquifer fluctuate with the tides,reaching the strongest in the middle of the ebb tide,with a lag compared to the tidal water level changes.Part of the infiltrated salt accumulates in the adjacent shallow aquifer and diffuses to the deep aquifer,and part is discharged to the river with inland groundwater and then flushed to the ocean by inland river water.
作者
叶逾
郭自来
唐腾宇
南统超
徐腾
谢一凡
鲁春辉
YE Yu;GUO Zilai;TANG Tengyu;NAN Tongchao;XU Teng;XIE Yifan;LU Chunhui(The National Key Laboratory of Water Disaster Prevention,Hohai University,Nanjing 210098,China;College of Water Conservancy and Hydropower Engineering,Hohai University,Nanjing 210098,China;Yangtze Institute for Conservation and Development,Hohai University,Nanjing 210098,China;College of Hydrology and Water Resources,Hohai University,Nanjing 210098,China)
出处
《水资源保护》
北大核心
2025年第5期278-284,共7页
Water Resources Protection
基金
国家重点研发计划项目(2024YFC3211600)
国家自然科学基金面上项目(42477061)。
关键词
潮汐
河口含水层
咸水入侵
地下水排泄
数值模拟
tide
estuarine aquifer
saltwater intrusion
groundwater discharge
numerical simulation
