海潮引起有越流的滨海承压含水层地下水头变化的数值模拟

海潮波动可以引起海岸带有越流的承压含水层地下水头发生波动。建立了基于有限差分法的滨海地区一维承压含水层地下水运动数值模型。通过将潮汐波动概化为正弦波，分别对初始水头水平及线性倾斜的承压含水层模拟了滨海地区有越流的承压含水层地下水头随潮汐波动的变化。通过对两种情形下的变化比较，结果表明，受海潮影响的滨海承压含水层地下水头与海潮有相似的波动特征，但变幅减小，受海潮的影响程度与离海岸的距离有关，随着离海岸距离的增加，地下水头的变幅及潮汐效率呈负指数函数衰减，水头倾斜情形下变幅更小，潮汐效率更小，滞后时间更短，地下水头对海潮的滞后时间随距离呈线性增加。

Numerical Modeling of Groundwater Level Oscillations in a Coastal Leaky Confined Aquifer Induced by the Tide

Groundwater levels in a coastal leaky confined aquifer may fluctuate as a result of the induction of the tide.A numerical model describing 1D groundwater flow in a coastal leaky confined aquifer is established in this paper based on the finite element method.By simplifying the fluctuation in the tide as a sinusoidal wave, groundwater level oscillations in a coastal leaky confined aquifer with horizontal and linear slope initial ground water levels are modeled.Comparison of the modeling results of these two cases shows that the groundwater le vel oscillations induced by the tide in the coastal confined aquifer are similar to those of the tide but the fluctuation ranges of groundwater levels are smaller than those of the tide.The degree of effect by the tide is related to distance from the coast.The fluctuation range of groundwater levels and the tidal efficiency decrease negatively exponentially with the distance from the coast.The fluctuation range, tidal efficiency and time lag of groundwater levels in the confined aquifer with horizontal initial groundwater level are smaller than those of the aquifer with linear slope initial groundwater level.The time lag of the groundwater levels to the tide increases linearly with the distance from the coast.