南通市地下水压缩开采对水质咸化的控制效应

Control effect of goundwater compression mining on water salinization in Nantong City

为了准确评价南通市地下水压缩开采对水质咸化的控制效应,根据南通市的水文地质条件,概化出了南通市的水文地质概念模型,建立了南通市地下水渗流与溶质运移三维耦合数值模型,分别预测了现状开采和压缩开采条件下2018-2034年逐年地下水水位和地下水中氯离子质量浓度的变化趋势。预测结果表明:现状开采条件下2034年底南通市第Ⅲ承压含水层中氯离子质量浓度大于250 mg/L和270 mg/L的面积分别达到355.17 km^2和30.67 km^2,2030-2034年咸化速率为9.59 km^2/a;压缩开采条件下2034年底氯离子质量浓度大于250 mg/L和270 mg/L的面积分别为329.21 km^2和1.76 km^2,2030-2034年咸化速率为7.52 km^2/a,压缩开采方案能有效控制第Ⅲ承压水的咸化问题。

In order to accurately evaluate the control effect of groundwater compression mining on water salinization in Nantong City,the hydrogeological conceptual model of Nantong City is generalized according to the hydrogeological conditions of Nantong City,and a three-dimensional coupled numerical model for groundwater seepage and solute transport in Nantong City is developed to predict the variation trends of groundwater level and the mass concentration of Cl^- in groundwater from 2018 to 2034 under the present and compressed mining conditions,respectively.The results shows that by the end of 2034 the areas of the third confined aquifer with the mass concentration of Cl^- greater than 250 mg/L and 270 mg/L will reach 355.17 km^2 and 30.67 km^2,respectively,with the salinization rate of 9.59 km^2/a from 2030 to 2034 at current condition,while under the condition of compressed mining,the areas with the mass concentration of Cl^- greater than 250 mg/L and 270 mg/L reach 329.21 km^2 and 1.76 km^2,respectively,with the salinization rate of 7.52 km^2/a from 2030 to 2034,indicating that the compression mining scheme can effectively control the problem of water salinization in the third confined aquifer.