不同土地利用类型下地表水和地下水的水化学特征及离子来源

Hydrochemical characteristics and ion sources of surface water and groundwater under different types of land use

为了探究土地利用方式对天津市地表水和地下水水化学特征的影响,运用水化学分析方法,测定天津市主要河流水和附近地下水的水化学成分,分析其空间特征.结果表明:①研究区地表水的主要水化学类型为Na·Mg-Cl·HCO_(3),地下水的主要水化学类型为Na·Ca-HCO_(3);②耕地类型下水中NO_(3)^(-)质量浓度高,部分耕地和草地类型下水中K^(+)质量浓度高,城乡居民工矿用地类型下水中Na^(+)和Cl^(-)质量浓度高;③地表水和地下水中Ca^(2+)、Mg^(2+)和HCO_(3)^(-)主要来源于碳酸盐岩的风化溶解,部分SO_(4)^(2-)来源于蒸发盐岩的溶解,Na^(+)、Cl^(-)和NO_(3)^(-)质量浓度主要受到人类活动的影响.

To explore the impact of land use on the hydrochemical characteristics of surface water and groundwater in Tianjin,hydrochemical methods were used to test the hydrochemical components of main river water and nearby groundwater samples in Tianjin,and the spatial characteristics of hydrochemical characteristics were analyzed.The results showed that:①The main hydrochemical type of surface water was Na·Mg-Cl·HCO_(3),and the main hydrochemical type of groundwater was Na·Ca-HCO_(3);②The mass concentration of NO_(3)^(-)in water was high in cultivated land types,while mass concentration of K^(+)was high in some cultivated land and grass-land types.The mass concentration of Na+and Cl^(-)in water was high in urban and rural residential in-dustrial and mining land types.③Ca^(2+),Mg^(2+),and HCO_(3)^(-)in surface water and groundwater mainly came from the weathering and dissolution of carbonate rocks,SO42-partially came from the dissolution of evaporite rocks,and the mass concentration of Na^(+),Cl^(-),NO_(3)^(-)were mainly influenced by human activities.