摘要
为给黔中安江地下河系统污染防治及乌江流域生态保护提供科学支撑,在水文地质调查和样品采集测试的基础上,综合运用水文地质条件分析、舒卡列夫分类法和派铂三线图、正态性检验和Grubbs检验法、污染指数法等方法,对安江地下河系统边界及水文地质特征、水化学成分及主要离子来源、背景值、污染现状及污染成因等进行了系统研究.研究结果表明,安江地下河系统面积约18.91 km2,其地下水化学类型为HCO3·SO4-Ca型水、HCO3-Ca·Mg型水、HCO3·SO4-Ca·Mg型水和SO4-Ca型水等4类,各类型占比大致相等,其地下水主控离子主要来源为娄山关组白云岩、栖霞组-茅口组灰岩等碳酸盐岩与龙潭组含硫矿物的溶解和沉淀;安江地下河系统已受到污染,污染程度最严重指标为总磷,其次为氟化物,再次为硫酸盐;栖霞组-茅口组灰岩含水岩组污染程度等级远高于娄山关组白云岩含水岩组.研究证明了安江地下河系统岩溶管道主要发育于栖霞组-茅口组,其次为娄山关组;含总磷、氟化物和硫酸根等无机污染物的地下水经岩溶管道向北东方径流迁移,污染安江地下河系统,并最终通过S50地下河出口排泄于乌江.本研究对于岩溶区地下河系统污染防治具有理论指导意义.
Abstract
[Objective]This study aims to establish a scientific framework for managing pollution in the Anjiang underground river system in central Guizhou and maintaining the ecological integrity of the Wujiang River basin.[Methods]The approach involves comprehensive hydrogeological surveys and analytical testing of water samples.We analyze hydrogeological conditions,apply the Shukarev classification system,utilize Piper's trilinear diagrams,conduct normality and Grubbs'tests,and calculate pollution indices.This investigation methodically examines the hydrogeological context,hydrochemical profiles,sources of major ions,background concentrations,and current pollution levels,and identifies the factors driving pollution in the Anjiang underground river system.[Results]The Anjiang underground river system covers approximately 18.91 square kilometers.The hydrochemical composi-tion is classified into four types:HCO3·SO4-Ca,HCO3-Ca·Mg,HCO3·SO4-Ca·Mg,and SO4-Ca,each con-stituting roughly equal proportions.The predominant ions mainly originate from the dissolution of carbonate rocks,specifically dolomite from the Loushanguan Formation and limestone from the Qixia Formation-Maokou Formation,as well as sulfur-bearing minerals from the Longtan Formation.The pollution levels are significant,with total phos-phorus,fluoride,and sulfate being the most crucial contaminants.Notably,the limestone aquifer of the Qixia For-mation-Maokou Formation has higher pollution level than the dolomite aquifer of the Loushanguan Formation.This study confirms that the karst conduit network in the Anjiang underground river system has developed primarily with-in the Qixia Formation-Maokou Formation,with substantial secondary development in the Loushanguan Formation.The groundwater,enriched with inorganic pollutants such as total phosphorus,fluoride,and sulfate ions,flows northeast through karst conduits,contaminating the Anjiang underground river system.This polluted water eventu-ally discharges into the Wujiang River via the S50 underground river outlet.[Conclusion]Our findings provide crucial theoretical support for the management and mitigation of pollution in karstic underground river systems.
维普
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