武隆—广杨地区水循环模式及水化学特征

Groundwater Circulation Mode and Water Chemistry Characteristics in Wulong—Guangyang Area

武隆—广杨地区地处渝黔交界,交通位置良好。为研究其地下水循环模式及其控制因素,2020年4月现场采集31组地下水样,利用统计分析、Piper图示、离子比例系数等方法对地下水的循环模式以及其水化学特征与差异进行了分析。结果显示,研究区存在四种循环模式,岩溶水I型、II型为循环深度不同,以大气降水补给为主,具有快速通道的循环模式,裂隙水III、IV型是在碎屑岩区域发育的浅、缓地下水循环模式;地下水中Ca^(2+)为主要阳离子,HCO_(3)^(-)为主要阴离子,主要水化学类型为HCO_(3)-Ca型水,裂隙水循环内部水化学组分复杂;地下水中化学组分复杂,方解石、白云石的溶解,以及离子交换过程是影响四种循环模式水化学组分特征的主控因素。

Wulong—Guangyang area is located on the border of Chongqing and Guizhou,it’s a typical southwestern carbonate rock exposed karst development area.The 31 groups sampled from this area were used to study the regional water cycle mode,which was important for the future construction of the area.Taking the four groundwater circulation modes in the study area as the research object,through the qualitative and quantitative analysis of the water chemical components of the samples,the characteristics of the four circulation modes and the causes of hydrochemistry are discussed.The results show that the main cation in this area is Ca^(2+),the main anion is HCO_(3)^(-),and the main water chemistry type is HCO_(3)-Ca type water.The difference in circulation mode will affect the local water chemistry type.Type I and Type II are different in circulation depth.Atmospheric precipitation replenishment mainly has a fast-track karst water cycle.Types III and IV cycles are shallow and slow cycle patterns developed in the clastic rock area.The chemical process of the water cycle is complex.The dissolution of calcite and dolomite,and the ion exchange process are the influence.The chemical composition of the water in the four circulation modes and the main controlling factors for its evolution.