Determination of aquifer roof extending under the sea from variable-density flow modelling of groundwater response to tidal loading: case study of the Jahe River Basin, Shandong Province, China
Determination of aquifer roof extending under the sea from variable-density flow modelling of groundwater response to tidal loading: case study of the Jahe River Basin, Shandong Province, China
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DOI：
10.1007/s10040-004-0347-z
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发表时间：
2004-06
影响因子：
2.8
通讯作者：
Jianmei Cheng;Chongxi Chen;Menrui Ji
中科院分区：
文献类型：
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作者：
Jianmei Cheng;Chongxi Chen;Menrui Ji
关于盐水侵入沿海承压含水层的研究的主要任务是预测淡水-盐水界面的位置，这可以根据含水层顶部在海底延伸的长度来确定。受潮汐影响的地下水位记录可用于推断水文条件和确定延伸到海底的含水层的水力参数。本文建立了一个三维变密度地下水流模型，利用山东省夹河流域地下水位潮汐效应资料确定了海底含水层的等效顶板长度。将钻孔中观测到的水头波动与计算值进行收敛，得到向海边界，并估算了延伸带的含水层参数。研究了含水层顶板长度和含水层参数对潮汐地下水波动的影响。得出结论，延伸到海底的含水层顶板的长度应与外推区的某些含水层参数相对应。因此，由潮汐效应信息确定的向海边界是水动力特性的等效边界，而不是承压含水层的真实边界
The main task of studies on salt-water intrusion into coastal confined aquifers is to predict the position of the fresh- salt-water interface, which can be determined from the length of the aquifer roof extending under the sea. Records of groundwater level affected by tides can be used to infer hydrological conditions and determine hydraulic parameters of an aquifer extending under the sea. In this paper, a three-dimensional, variable-density groundwater flow model has been developed to determine the equivalent roof length of an aquifer extending under the sea from the tidal-effected data of groundwater level in the Jahe River Basin, Shandong Province, China. The seaward boundary is obtained by converging hydraulic head fluctuations observed in drill holes with calculated values, and the aquifer parameters in the extending zone are estimated. The impacts of aquifer roof length and aquifer parameters on the fluctuation of tidal groundwater are studied. It is concluded that the length of the aquifer roof extending under the sea should correspond with certain aquifer parameters in the extrapolation zone. Therefore, the seaward boundary determined from tidal-effect information is the equivalent boundary in hydrodynamic characteristics rather than the true boundary of the confined aquifer