卫宁北山山前地下水特征分析及水质评价

Characteristics of groundwater in the piedmont area of the Weiningbeishan region and water quality evaluation

以卫宁北山石空段地下水为研究对象,结合中宁平原盆地已有的地质、水文地质资料,介绍了山前地下水水文地质、赋存、补给径流排泄特征、水化学特征和地下水变化动态。地下水受构造地貌控制由山前流向黄河,补给来源主要为大气降水,水岩相互作用从A1—A5点以溶滤、A6—A7混合作用为主,逐渐演变成A8—A10的以浓缩-蒸发为主。水质测试表明:地下水由山前至滨河由苦咸水转化为淡水(微咸水),水化学类型由Cl·SO4-Na(Cl·SO4-Na)型转为HCO3·SO4-Ca·Na型,平原区水质属于较差类别。受人类活动影响,主要污染物为氨氮等。

This paper presents the hydrogeological features,occurrence,discharge of feeder,water chemical analysis and dynamic changes of groundwater from the Shikong section of Ningweibeishan region,Ningxia,combined with the previous geological,hydrogeological data for the plain basin. It is indicated that,the groundwater shows a significant control by the tectonic landform,flowing from the piedmont to the Yellow River,and is mainly sourced from atmospheric precipitation. The water rock interaction evolved gradually from leaching（ sample points A1—A5）,mixing effects（ sample points A6—A7） to concentration-evaporation（ sample points A8—A10）. Water quality tests suggest that,the groundwater transformed from brackish water to fresh water（ slightly saline water） from the piedmont to riverside,and the hydrochemical types vary from Cl·SO4- Na（ Cl·SO4- Na） type to HCO-3·SO4- Ca·Na type. Groundwater quality in the plain area belongs to a poor level as impacted by human activities,and the main pollutants are ammonia nitrogen.