【摘要】 银川平原属中温带干旱区,蒸发强烈,潜水水质差,承压水是银川市地下水开采的主要水源。通过ArcMap空间分析、传统作图分析、氢氧同位素分析等方法,分析银川地区承压含水层水化学特征及各含水层水化学特征的差异,探讨了承压水水化学分布特征的控制因素。研究表明,潜水和承压水水化学分布特征在水平和垂直方向上均存在较大差异;第一和第二承压水水化学分布特征在水平方向上相似,在垂直方向上存在一定差异。水平方向上,两层承压水水化学特征存在一定分带性,而潜水无明显规律性。两层承压水在靠近西侧补给区溶解性总固体（TDS）较小,阴离子以HCO₃^-为主,阳离子以Mg²⁺和Ca²⁺为主,向东溶解性总固体逐渐增加,在银川断裂附近,阴离子变为以Cl-和SO₄^2-为主,阳离子以Na+为主。垂向上,由于银川断裂贯穿承压和潜水含水层,且潜水水位高于承压水位,第二承压水可能主要受到更深层地下水沿着断裂的混入作用,第一承压水可能同时受到更深层地下水和潜水的混入,使得在银川断裂附近,部分第二承压水TDS大于第一承压水,且具有更高含量的Na⁺和Cl^-,及更低含量的Ca²⁺和HCO₃^-,也有部分第一承压水TDS大于第二承压水,该部分第一承压水中的个别水样TDS大于潜水。由此得出,银川断裂的发育及其对潜水及承压含水层的贯通作用是控制该区地下水水质的一个重要因素。如果承压水继续过量开采,承压水位持续下降,将进一步激发潜水和更深层地下水的混入,从而导致承压水质恶化。因此控制银川区承压水的过量开采,对于承压水资源的可持续利用至关重要。更多还原

【Abstract】 The strong evaporation have made the unconfined water have poor quality in Yinchuan plain,the middle temperate arid region. Confined water is the main water source for the mining of groundwater in Yinchuan City. Spatial analysis of Arc Map,conventional graphical methods,stable isotopic were used to analyze the distribution characteristics of confined water chemistry,and the difference among different aquifers. Then the controlling factors of confined water chemistry were discussed. The results show that the hydrochemicalcharacteristics of unconfined water are significantly different with the two confined water in horizontal and vertical direction. The first and the second confined water have similar changing trends in the horizontal direction,but certain difference exist between them in the vertical direction. In the horizontal direction,the confined water near the west side recharge area has small TDS with the main anion of HCO₃^-,and the main cation of Mg²⁺and Ca²⁺. The TDS increase eastwards. Around the Yinchuan fault the chief anion are Cl^-and SO₄^2-,and the chief cation is Na⁺. The unconfined water,however,has no obvious zoning characteristics in the horizontal direction. In vertical direction,owing to the Yinchuan fault and the head difference between the two layers of confined water,the second confined water may be mixed by deeper layer groundwater,and the first confined water may be mixed by the deeper layer groundwater and unconfined water simultaneously. These make some second layer confined water samples have higher TDS,more Na+and Cl^-,and less Ca²⁺and HCO₃^- than the first layer confined water. And some first layer confined water samples have higher TDS than the second layer confined water, and individual samples higher than the unconfined water. These shows that the development of Yinchuan fault throughout the entire confined and unconfined aquifer is significant to the groundwater quality. If excessive exploitation is conducted continually to the confined water,the confined water lever will continued to fall,which will further stimulate the interfusion of the unconfined and deeper layer water eventually lead to the deterioration of the confined water quality. Therefore controlling the excessive exploitation of confined water is significant to sustainable utilization of confined water resources in Yinchuan.更多还原