银川地区承压水水化学特征及控制因素

发布时间：2018-06-08 22:48

本文选题：水化学特征 + 断裂　；参考：《水文地质工程地质》2017年02期

【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HCO_3~-为主,阳离子以Mg~(2+)和Ca~(2+)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SO_4~(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Ca~(2+)和HCO_3~-,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。
[Abstract]:Yinchuan Plain is a middle temperate arid area with strong evaporation and poor water quality. Confined water is the main source of groundwater exploitation in Yinchuan. By means of ArcMap spatial analysis, traditional mapping analysis, hydrogen and oxygen isotope analysis, the chemical characteristics of confined aquifer and the differences of chemical characteristics of each aquifer are analyzed, and the controlling factors of the chemical distribution of confined water are discussed. The results show that the chemical distribution characteristics of water in diving and confined water are different in horizontal and vertical directions, and the chemical distribution characteristics of water in the first and second pressure are similar in horizontal direction and are different in vertical direction. In the horizontal direction, the chemical characteristics of the two-layer confined water have some zonation, but the diving has no obvious regularity. The dissolved total solids TDSs in the two-layer confined water near the western recharge area are relatively small, the anions are mainly HCO3-, the cations are Mg2) and Cajian2), the total dissolved solids in the eastward direction increase gradually. In the vicinity of Yinchuan fault, the anions change to Cl- and SOS4C2-2). The cations are mainly Na. Vertically, because the Yinchuan fault runs through the confined and diving aquifers, and the diving water level is higher than the confined water level, the second confined water may be mainly affected by the mixing of deeper groundwater along the fault. The first confined water may be mixed with deeper groundwater and diving at the same time, so that in the vicinity of the Yinchuan fault, some of the second confined water TDs is larger than the first confined water. Some of the first confined water TDs are larger than the second confined water, and some of the first confined water samples are larger than those of the second confined water, and some of the first confined water samples have more TDs than the diving water. It is concluded that the development of Yinchuan fault and its transfixion to groundwater and confined aquifer is an important factor to control the groundwater quality in this area. If confined water continues to be overexploited, the pressure level will continue to fall, which will further stimulate the mixing of submersible and deeper groundwater, leading to the deterioration of confined water quality. Therefore, it is very important for the sustainable utilization of confined water resources to control the excessive exploitation of confined water in Yinchuan area.
【作者单位】：中国地质大学(北京)水资源与环境学院;宁夏地质调查院;中国地质大学(北京)/生物地质与环境地质国家重点实验室;中国地质大学(北京)/地下水循环与环境演化教育部重点实验室;
【基金】：国家自然科学基金项目(41272269)
【分类号】：P641.3

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