唐山曹妃甸浅层水咸化机制及反向模拟

采集了唐海至渤海湾剖面的13组水样,分析了研究区浅层地下水的化学特征及成因机制.运用Phreeqc软件反向模拟了地下水流路径上浅层微咸水(咸水)的补给机理及咸化过程.结果显示:浅层地下水由北向南,ρ(TDS)由0.36 g/L逐渐上升到39.2 g/L,水化学类型从HCO3·Cl-Ca·Mg·Na型过渡为Cl· HCO3-Na型再转变为Cl-Na· Mg型.微咸水形成以咸淡混合为主,期间伴随着岩盐、斜长石、CO2、高岭石、钾长石、石膏的溶解及钙蒙脱石、方解石的沉淀析出.咸水形成初期主要受海水入侵影响,后期受蒸发作用影响又进一步咸化.

Backward Simulation and the Salinization Mechanism of the Shallow Groundwater in Caofeidian, Tangshan

In this paper,chemistry characteristics and forming mechanism of 13 shallow groundwater samples collected along the section from Tanghai to Bohai bay were analyzed.Backward simulation of the recharge and the salinization process of the shallow brackish water(saline water) along the flow path were performed by using Phreeqc program.The results showed that the TDS of the groundwater in Caofeidian from north to south increased from 0.36 g/L to 39.2 g/L.Types of the groundwater changed from HCO3·Cl-Ca·Mg ·Na to Cl·HCO3-Na,then to Cl-Na·Mg.The formation of brackish water was mainly caused by the mixtion of the fresh and the salty water,with the dissolution of the rock salt,plagioclase,CO2 gas,kaolinite,potassium feldspar,gypsum and the precipitation of the montmorillonite and calcite.Saline water was formed firstly by the seawater intrusion,and further mineralized as evaporation.