潮汐作用下分层非均质含水层海水入侵的渗流试验和数值模拟  

Infiltration experiments and numerical simulations of seawater intrusion in stratified heterogeneous aquifers affected by tides

作　　者：方运海 汤海松 郑天元 郑西来[2] 钱家忠[1] FANG Yunhai;TANG Haisong;ZHENG Tianyuan;ZHENG Xilai;QIAN Jiazhong(School of Resources and Environmental Engineering,Hefei University of Technology,Hefei 230009,China;College of Environmental Science and Engineering,Ocean University of China,Qingdao 266100,China)

机构地区：[1]合肥工业大学资源与环境工程学院,安徽合肥230009 [2]中国海洋大学环境科学与工程学院,山东青岛266100

出　　处：《河海大学学报（自然科学版）》2024年第6期23-29,共7页Journal of Hohai University(Natural Sciences)

基　　金：国家自然科学基金项目(42302268);中国博士后科学基金项目(2022M720979);中央高校基本科研业务费专项资金资助项目(JZ2023HGQB0166)。

摘　　要：为了更好地保护沿海地下淡水资源,探究复杂水文地质条件下滨海含水层海水入侵的水动力机制,结合室内渗流试验和数值模拟方法,研究了含水层非均质性和潮汐作用共同影响下的海水入侵问题。结果表明:静态和潮汐海洋边界下滨海非均质含水层咸淡水空间分布显著不同,潮汐作用会减小下咸水楔侵入距离约30.8%,导致下咸水楔咸淡水混合带宽度增大3倍;潮汐作用会在含水层上部潮间带区域形成上咸水楔,地下淡水排泄是潮间带咸水聚集的关键阻力,地下淡水排泄量越大,潮间带上咸水楔面积越小;在相同水力梯度作用下,静态和潮汐海洋边界下的均质、非均质含水层海水入侵距离均随着渗透系数增大而增大。To better protect fresh groundwater resources,it is urgent to explore the hydrodynamic mechanism of seawater intrusion in coastal aquifers under complex hydrogeological conditions.In this study,a rigorous combination of laboratory experiments and numerical simulations was used to explore the mechanism of seawater intrusion under the combined influence of aquifer heterogeneity and tides.The results showed that spatial distribution of saltwater-freshwater in coastal heterogeneous aquifers was significantly different under the static and tidal sea boundaries.Tidal action reduced the intrusion distance of the saltwater wedge by 30.8%,resulting in a threefold increase in the width of the mixing zone around the saltwater wedge.Tidal action generated an upper saline plume(USP)in the intertidal zone,and fresh groundwater discharge was the key resistance to the accumulation of saltwater in the USP.When the flux of fresh groundwater discharge increased,the USP area would decrease.Under the same hydraulic gradient,the distance of seawater intrusion increased with the increasing permeability,regardless of static/tidal and homogeneous/heterogeneous conditions.

关 键 词：滨海含水层 海水入侵 地下水排泄 非均质 潮汐作用 

分 类 号：TV138[水利工程—水力学及河流动力学] P731.23[天文地球—海洋科学]