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地下坝作为防治海水入侵的有效手段，已得到广泛应用，但其可能会导致上游咸水残留，从而限制地下水的开采。目前关于残留咸水的研究大多忽略了含水层非均质的影响或局限于实验室尺度，本文通过建立场地尺度的数值模型，模拟了不同层状非均质条件下地下坝建设前后的海水入侵过程，以残留咸水楔回退率、总残留盐去除率和地下水排泄量百分比为指标阐明了层状非均质对于残留咸水淡化过程的影响机制。研究结果表明：在层状非均质含水层中，残留咸水的淡化行为主要受到下层含水层渗透性的影响；低渗透层中渗透系数的取值越大，淡化速率越快；而低渗透层厚度对于残留咸水的淡化过程影响较小，且只体现在快速淡化阶段。本研究对于地下截渗工程建设和滨海地下水资源的开发利用具有重要的科学意义和应用价值。
Abstract：Widespread use of subsurface dams as an effective control mechanism may lead to residual saltwater in landward directions and limit the exploitation of groundwater. However, most of the current studies neglect the influence of heterogeneity, or are limited to laboratory scale. In this paper, the seawater intrusion process before and after the construction of subsurface dams under different layered heterogeneous conditions was simulated by a site-scale numerical model. The effects of different layered heterogeneous conditions on the desalination process of residual saltwater and groundwater discharge process are discussed by taking the wedge regression rate of residual saltwater, the removal rate of residual total salt and the percentage of groundwater discharge as indexes. The results show that the change of hydraulic conductivity of the lower aquifer has a significant influence on the regression effect of residual saltwater. The larger the value of low permeability layer, the faster the regression rate. However, the thickness of low permeability layer has little influence on the desalination process of residual saltwater.
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基本信息:
DOI：10.16441/j.cnki.hdxb.20240042
中图分类号:P641.2
引用信息:
[1]曹燃,郑天元,张博,等.地下坝上游非均质含水层残留咸水淡化过程研究[J].中国海洋大学学报(自然科学版),2025,55(03):104-115.DOI:10.16441/j.cnki.hdxb.20240042.
基金信息:
国家自然科学基金项目(42272282,42202270)资助~~
2025-02-19
2025-02-19