不透水面影响下海岛淡水透镜体的形成与演化  

Formation and evolution of freshwater lens in an island under influence of impervious surface

作　　者：凌子涵 束龙仓[1,2] 王然 LING Zihan;SHU Longcang;WANG Ran(College of Hydrology and Water Resources,Hohai University,Nanjing 210098,China;State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering,Hohai University,Nanjing 210098,China)

机构地区：[1]河海大学水文水资源学院,江苏南京210098 [2]河海大学水文水资源与水利工程科学国家重点实验室,江苏南京210098

出　　处：《水利水电科技进展》2022年第1期97-102,共6页Advances in Science and Technology of Water Resources

基　　金：江苏省研究生科研创新计划(KYCX20_0461);中央高校基本科研业务费专项(B200203046)。

摘　　要：以某海岛的水文地质资料为基础,对研究区水文地质条件进行概化,并使用Visual MODFLOW软件构建了该海岛淡水透镜体的二维模型,通过改变不透水面的覆盖范围,模拟透镜体形态及储水量的变化。数值模拟结果表明,初始状态下岛屿淡水透镜体的最大厚度约为15.6 m;在设置不透水面后,淡水透镜体大约在15a之后再次达到稳定状态,设置不透水面一侧的淡水透镜体下界面轮廓向内凹陷,淡水透镜体的最大厚度减小至14.6 m,岛屿地下淡水储量减少了20.23%。对影响淡水透镜体的4种影响因素进行灵敏度分析,结果表明给水度对岛屿地下淡水储量影响最大,其后依次为降雨入渗补给系数、渗透系数和不透水面覆盖范围。Based on the hydrogeological data of an island,the hydrogeological conditions of the study area were generalized,and the corresponding two-dimensional numerical model was established by using Visual MODFLOW.The formation and water storage capacity variation of the lens was simulated by changing the coverage area of the impervious surface.The simulation results show that the maximum thickness of the initial island freshwater lens is 15.6 m.After configuration of the impermeable surface,the freshwater lens is stable again after 15 years.The outline of the lens with impervious surface is concave inward,and the maximum thickness is reduced to 14.6 m,and the underground fresh water storage of the island is reduced by 20.23%.Sensitivity analysis of the four influencing factors of the fresh water lens shows that the aquifer specific yield has the greatest impact on the underground freshwater storage,and then follows the impact of precipitation infiltration intensity,permeability coefficient and impervious surface coverage.

关 键 词：海岛 淡水透镜体 不透水面 灵敏度 

分 类 号：P641[天文地球—地质矿产勘探]