泰安市城区岩溶地下水水化学特征及成因分析

Hydrochemical Characteristics and Formation Analysis of Karst Groundwater in District Area of Tai'an City

摘要:

岩溶地下水是泰安市城区重要供水水源，近年来随着气候环境变化和人为活动的影响，岩溶地下水水化学特征日趋复杂，但其水化学特征及成因尚不明晰。为识别研究区地下水水化学特征、成因机制，本文采用数理统计方法、离子比值、水化学图解等方法，研究了该区岩溶地下水的水文地球化学特征。结果表明：研究区内岩溶地下水水化学类型主要为HCO3Ca型、HCO3·SO4Ca 型、HCO3·SO4·ClCa型。地下水水化学成分主要受水岩相互作用控制，以溶滤作用为主，地下水中的Ca2+、Na+、HCO-3、SO2-4主要来源于方解石、白云石的碳酸盐岩及石膏、盐岩等蒸发岩的溶解，且存在逆向的阳离子交替吸附作用，导致Ca2+含量增加，Na+含量减少，人为活动影响导致地下水中Cl-、NO-3浓度增加。研究成果为研究区内岩溶地下水的合理开发与保护提供了依据。

Abstract:

Karst groundwater is an important water source in Tai'an city. In recent years, accompanying with the influence of climate change and human activities, hydrochemical characteristics of karst groundwater are increasingly complex, but its hydrochemical characteristics and causes are not clear. In order to identify hydrogeochemical characteristics and formation mechanism of karst groundwater in the study area, hydrogeochemical characteristics of karst groundwater in the study area are studied by means of mathematical statistics, ion ratio and hydrochemical diagrams. It is showed that main hydrochemical types of karst groundwater in the study area are HCO3-Ca, HCO3·SO4-Ca and HCO3·SO4·Cl-Ca. Hydrochemical composition of groundwater is mainly controlled by the interaction of water and rock, and mainly by solution filtration. Ca2+, Na+, HCO-3 and SO2-4 in groundwater are mainly derived from the dissolution of carbonate rocks, such as calcite and dolomite, gypsum and salt rock, and there is reverse cation alternating adsorption. The content of Ca2+ will increase, while the content of Na+ content will decrease. The increase of the concentration of Cl and NO-3 in groundwater is mainly influenced by human activities. The research results will provide a basis for rational development and protection of karst groundwater in the study area.