汉中盆地西侧土关铺—大安镇一带山区泉水水化学特征及成因机制

Hydrochemical Characteristics and Genetic Mechanism of Spring Water in the Mountainous Area from Tuguanpu to Da’an Town on the West Side of Hanzhong Basin

泉水是汉中盆地西侧土关铺—大安镇一带山区居民重要的饮用水源,对该区泉水的水化学特征及其成因机制研究对当地水资源的开发和保护具有重要的指导意义。本次研究共采集了13件泉水样品进行水质分析,综合运用数理统计、Piper三线图、Gibbs图解、饱和指数法以及主要离子比值等方法综合分析研究区泉水水化学特征及其成因机制。结果显示:汉中盆地西侧山区泉水为弱碱性低矿化度水,水化学组分中阳离子以Ca^(2+)和Mg^(2+)为主,阴离子以HCO_(3)^(-)为主,泉水的水化学类型主要为HCO_(3)-Ca·Mg型,水化学类型主要受岩石风化作用控制。所有样品的CO_(2)(g)均未达到饱和,可再溶于地下水;大部分泉水的白云石和方解石矿物处于非饱和状态,仍可发生这两种矿物的溶解,部分泉点如太星垭泉(S_(06))、金家坎泉(S_(07))、水磨沟泉(S_(08))和陈家营泉(S_(11))的方解石和白云石矿物以及南沟门泉(S_(12))的方解石已达到过饱和,即将发生沉淀。人类活动对泉水水化学影响较小,研究区泉水样品中的离子主要受碳酸盐岩的溶解控制,部分来自硅酸盐岩的溶解。

Spring water is the important drinking water source for the village of Tuguanpu to the Da’an Town on the west side of the Hanzhong basin.The Study on the hydrochemical characteristics and genetic mechanism is of great significance to guide the development and protection of local water resources.In this study,13 spring water samples were collected for water quality analysis.Mathematical statistics,Piper trigram,Gibbs diagram,saturation index method and major ion ratios were used to comprehensively analyze the hydrochemical characteristics and genetic mechanism of the spring water in the study area.The results show that the spring water in the mountainous area on the west side of Hanzhong basin is weakly alkaline and low salinity water.In the hydrochemical composition,the cation is dominated by Ca^(2+)and Mg^(2+),while the anion is dominated by HCO_(3)^(-).The main hydrochemical type of the spring water is HCO_(3)-Ca·Mg,which is mainly controlled by the weathering of rocks.The CO_(2)(g)in all water samples is not saturated and could be redissolved in groundwater.The dolomite and calcite of most spring water are in an unsaturated state,and the dissolution of them can still occur.The calcite and dolomite of Taixingya spring(S_(06)),Jinjiakan spring(S_(07)),Shuimogou spring(S_(08))and Chenjiaying spring(S_(11)),and the calcite of Nangoumen spring(S_(12))have been oversaturated and are about to precipitate.Human activities slightly influence on the hydrochemistry of spring water.The ions in the spring water samples in the study area are mainly from the dissolution of carbonate rocks,and partly from the dissolution of silicate rocks.