降雨事件下西南岩溶区地下水环境背景值获取方法探究  

Investigation on the Method of Obtaining Environmental Background Values of Groundwater in Karst Area,Southwest China Under Rainfall Events

作　　者：彭聪 梁建宏[1,2,3,4] 潘晓东 任坤[1,2,3] 曾洁 蒋丹丝[1,2,4] PENG Cong;LIANG Jian-hong;PAN Xiao-dong;REN Kun;ZENG Jie;JIANG Dan-si(Key Laboratory of Karst Dynamics of Ministry of Natural Resources/Guangxi,Institute of Karst Geology,Chinese Academy of Geological Sciences,Guilin 541004,Guangxi,China;International Research Center on Karst Under the Auspices of UNESCO,Guilin 541004,Guangxi,China;Guangxi Karst Resources and Environment Engineering Technology Research Center,Guilin 541004,Guangxi,China;Pingguo Karst Ecosystem National Observation and Research Station in Guangxi,Pingguo 531406,Guangxi,China)

机构地区：[1]中国地质科学院岩溶地质研究所自然资源部/广西壮族自治区岩溶动力学重点实验室,广西桂林541004 [2]联合国教科文组织国际岩溶研究中心,广西桂林541004 [3]广西岩溶资源环境工程技术研究中心,广西桂林541004 [4]广西平果喀斯特生态系统国家野外科学观测研究站,广西平果531406

出　　处：《地球科学与环境学报》2025年第1期67-81,共15页Journal of Earth Sciences and Environment

基　　金：广西重点研发计划项目(桂科AB21196026);广西自然科学基金项目(2023JJD150024);中国地质科学院岩溶地质研究所基本科研业务费专项资金项目(2023018);国家自然科学基金项目(42402258)。

摘　　要：地下水环境背景值是进行地下水超标成因判定及人为活动对地下水环境影响识别的重要标尺。西南岩溶区降雨丰富且时间不均,受降雨影响,岩溶地下水循环迅速,因此,探究降雨事件下西南岩溶区地下水环境背景值获取方法具有重要意义。分别利用水化学图法、Grubbs法和水化学图结合Grubbs法对降雨前后的水化学指标进行异常数据识别,并对比分析各方法识别异常数据效果,计算各指标的背景特征值。结果表明:在降雨前后,不同异常数据识别方法得出的地下水环境背景特征值均存在不同程度的差异,其中水化学图结合Grubbs法可将降雨事件的影响降至最低;水化学图结合Grubbs法在降雨前识别异常数据22组,降雨后异常数据识别率为79.2%(19组),重复率为70.8%(17组),且在降雨前后得出的背景特征值聚集性更好,差异性更小。综上所述,降雨事件会影响岩溶区地下水环境背景值统计和表征,而水化学图结合Grubbs法为最优的降雨事件异常数据识别方法,建议地下水采样应尽量避开降雨事件,从而更准确地获取岩溶区地下水环境背景值。The environmental background value of groundwater is an important criterion for determining the causes of groundwater exceedance and identifying the impact of anthropogenic activities on the groundwater environment.In Southwest China,rainfall is abundant and uneven in time,and the karst groundwater cycle is rapid under the influence of rainfall,so it is of great significance to investigate the method of obtaining environmental background values of groundwater in karst area,Southwest China under rainfall events.The anomalous data of water chemistry indicators before and after rainfall were identified by the hydrochemistry map method,Grubbs method and hydrochemistry map combined with Grubbs method,respectively.The effects of the above methods in identifying the anomalous data were compared,and the background eigenvalues of each indicator were calculated.The results show that the background eigenvalues of groundwater environment derived from different anomaly identification methods differ to different degrees before and after rainfall events;the hydrochemistry map combined with Grubbs method can minimize the impact of rainfall events;the method identifies 22 groups of anomalous data before rainfall,and the anomalous data identification rate after rainfall is 79.2%(19 groups)with a repetition rate of 70.8%(17 groups);the background eigenvalues derived before and after the rainfall event are better clustered and less different.In summary,rainfall events affect the statistics and characterization of the environmental background values of groundwater in karst areas,and the hydrochemistry map combined with Grubbs method is the optimal method for identifying anomalous data from rainfall events.So,it is recommended that groundwater sampling should avoid rainfall events as much as possible,so as to more accurately obtain the environmental background values of groundwater in karst areas.

关 键 词：地下水 环境背景值 水化学图法 Grubbs法 异常数据 马氏距离 降雨事件 岩溶区 

分 类 号：P641[天文地球—地质矿产勘探]