Groundwater Dynamics and Salinity in Coastal Barriers
Groundwater Dynamics and Salinity in Coastal Barriers
复制标题
沿海屏障的地下水动态和盐度
DOI：
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发表时间：
1999
期刊：
影响因子：
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通讯作者：
P. Nielsen
中科院分区：
文献类型：
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作者：
P. Nielsen
定性描述的基础上，现场测量给出了一个简单的建模框架，在沿海屏障的水位高度和盐度结构。在宽度不到一公里的沿海屏障中，地下水位的形状和盐度结构与传统的情况大不相同。在这个尺度上，由海洋一侧波浪爬高引起的额外的地下水位高度可以驱动显著的向陆地的地下水速度。这样做的一个主要后果是，任何排入含水层的废水，包括海滩上的石油泄漏，都将流向陆地而不是海洋。第二，咸地下水向陆地的流动使淡水透镜比“吉本-赫兹伯格厚度”薄得多。浅层含水层模型的地下水位，包括定量边界条件，占波浪和潮汐的影响。盐度结构是仿照淡水透镜的厚度，占淡水补给以及对流和扩散盐运输。现场测量表明，一维建模可以做一个简单的解耦模型，除了在一个狭窄的（一个或两个米）扩散边界层内的向陆地一侧的障碍，其中淡水位移厚度变化非常迅速。
A qualitative description based on field measurements is given together with a simple modelling framework for watertable heights and salinity structure in coastal barriers. In coastal barriers of width less than one kilometre the shape of the watertable and the salinity structure are quite different from the classical scenarios. On this scale the extra watertable height caused by wave runup on the ocean side can drive a significant landward ground water velocity. A primary consequence of this is that any wastewater released into the aquifer, including oil spills on the beach, will travel towards the land rather than towards the ocean. Secondly, this landward flow of salty groundwater makes the freshwater lens much thinner than the "Ghyben-Herzberg thickness". A shallow aquifer model is presented for the watertable including quantitative boundary conditions that account for the effects of waves and tides. The salinity structure is modelled in terms of the thickness of the freshwater lens, accounting for freshwater recharge as well as convective and diffusive salt transport. The field measurements indicate that 1D modelling can be done with a simple uncoupled model except within a narrow (one or two metres) diffusive boundary layer on the landward side of the barrier within which the freshwater displacement thickness varies very rapidly.