天津市平原区咸淡水界面下移特征分析

Characteristics of down-movement of the fresh-saline groundwater interface in the plain region of Tianjin

本文通过对开采条件下水动力场和水化学场变化特征的分析,认为集中超采深层地下水引发的浅层咸水向深层淡水的越流,是第Ⅱ含水组水质咸化的根本原因。并从咸水下移溶质运移模拟、渗透速率、粘性土层的越流滞后等方面,讨论了咸淡水界面下移速率及其影响因素。

The down-movement of shallow saline groundwater and the deterioration of deep groundwater are important geological environment problems in the plain region of Tianjin. Based on an analysis of the characteristics of hydrodynamic and hydrochemical fields under the explloitation conditions, the following conclusions can be drawn： The main reason for salinization in the second aquifer is that leakage occurs from shallow saline groundwater to deep fresh groundwater owing to groundwater over-exploitation. The downward movement velocity of the saline groundwater and its influence factors were discussed, concerning the aspects of solute transport, filtration velocity and delayed leakage in the cohesive layer.