淄河源区浅层地下水化学特征及主要离子来源研究

Hydrochemical Characteristics and Main Ion Sources of Shallow Groundwater in Zihe River Source Region,Shandong,China

运用水文地质现场调查和水文地球化学方法对淄河源区浅层地下水化学特征及主要离子来源进行了研究。结果表明:淄河源区内浅层地下水有3类:第四系松散岩类孔隙水、碳酸盐岩岩溶裂隙水和块状岩类风化裂隙水,水质类型分别为:HCO3·SO4-Ca·Mg型、HCO3·SO4-Ca·Mg型和HCO3·SO4-Ca型。3类地下水中Ca^2+、Mg^2+、HCO^-3浓度在含水层中相对稳定,而Na^+、K^+、NO^-3、Cl^-浓度变化较大,受环境因素的影响较明显。作为主要供水对象的碳酸盐岩岩溶地下水中,其化学组分Ca^2+主要来源于白云岩与方解石的溶解,部分来源于含Cl-、NO-3污染物的入渗以及石膏的溶解;Mg2+来源于白云石的溶解;HCO^-3主要来源于方解石与白云石的共同溶解,其次还受降雨补给影响;SO2-^4有3个来源,其主要来源于石膏层的溶解和黄铁矿的氧化。综合表明:淄河源区地下水水质较好,各项指标均达到地下水III类水水质标准,浅层地下水水质主要与该地区降水、地下水流动条件及碳酸盐岩裸露或浅埋藏有关。研究成果将对淄河源区规划建设岩溶地下水源地,合理利用和保护岩溶地下水资源提供科学决策依据。

The hydrogeological site investigation and hydrogeochemical methods were used to study the chemical characteristics and main ion sources of shallow groundwater in the source region of the Zihe River.The research showed that there are three types of shallow groundwater in the source region of the Zihe River:Quaternary loose pore water,carbonate rock karst groundwater and massive rock weathered fissure water.The water quality types are respectively:HCO3·SO4-Ca·Mg type,HCO3·SO4-Ca·Mg type and HCO3·SO4-Ca type.The concentrations of calcium,magnesium and bicarbonate ions in the three types of groundwater are relatively stable in the aquifer,while the concentrations of sodium,potassium,nitrate and chloride in the groundwater of the study area vary greatly,which are affected by environmental factors.As the main water supply target,the main chemical components of carbonate karst groundwater,calcium ions are mainly derived from the dissolution of dolomite and calcite,and partly from the infiltration of chloride ions and nitrate ions and the dissolution of gypsum.Magnesium ion is derived from the dissolution of dolomite;bicarbonate ion is mainly derived from the co-dissolution of calcite and dolomite,and secondly by rainfall replenishment;sulfate ion has three sources,but mainly from the dissolution of gypsum layer and the oxidation of pyrite.The comprehensive results showed that the groundwater quality in the source area of the Zihe River is good,and all the indicators have reached the groundwater Class III water quality standard.The shallow groundwater quality is mainly related to the precipitation,groundwater flow conditions and bare or shallow burial of the carbonate.The research will provide a scientific decision-making basis for the planning and construction of karst groundwater source areas in the source region of the Zihe River,and rational utilization and protection of karst groundwater resources.