[关键词]
[摘要]
地下水中化学组分的种类、分布在一定程度上可以揭示地下水与环境的相互作用机制。通过对山东省梭罗树 水源地的24 组地下水样本中主要离子成分( H CO3 - 、Cl- 、SO4 2- 、K+ + Na+ 、Ca2+ 、Mg 2+ ) 进行聚类分析( H CA) , 将水样分成C1 、C2 及C3 三簇, 再利用PCA 对地下水的8 种化学指标进行降维处理, 将其转化为P C1 、PC2 及PC2 三个综合指标, 然后综合PCA、Piper 图的分析结果, 以及各水样点的分布位置、围岩类型等条件对三簇水样点的水 化学特征及形成机理进行了分析。结果显示, C1 簇水样为松散岩类孔隙水, P C1 和PC3 指标反映其主要受溶解作 用、淋滤作用及离子交换作用影响, 水化学类型以H CO3 # Cl2Ca# Mg 型或Cl # H CO32Ca# Mg 型为主; C2 簇水样 为构造裂隙水, PC1 和PC2 指标反映其中的溶解作用及淋滤作用比C1 弱, 大部分离子成分含量较C1 低, 但围岩中 碳酸盐矿物、含镁矿物多, 使得CO-3 及Mg 2+ 有不同程度的增加, 水化学类型以HCO32M g# Ca 型或者H CO32Ca 型 为主; C3 簇水样为风化裂隙水, P C1 和PC2 指标反映其中溶解作用、淋滤作用更弱, 水质相对较好, 但季节性变化较 大, 同时由于岩石中含有可溶性氟, 使得F2 有一定程度的增加, 水化学类型以H CO3 # SO42Ca# Mg 型为主。
[Key word]
[Abstract]
Chemical compositions and distr ibution in gr oundw ater can rev ea l the interaction mechanism between g ro undwater and the environment to some extent. H ier archical cluster analysis ( H CA) was used to analyze the main index es ( H CO-3 , Cl- , SO4 2- , K+ , Na+ , Ca2+ , and Mg2+ ) of 24 g ro undwater samples, which wer e div ided into thr ee clusters ( C1 , C2 , and C3 ) . Pr inci2 pal compo nent analy sis ( PCA) w as used to perfo rm dimension reduction tr eatment o n eight chemical index es of gr oundw at er, and three comprehensiv e index es ( PC1 , P C2 and P C3 ) wer e obtained. The chemical character istics and formation mechanism of gr oundwat er w ere analyzed using the PCA and piper diagr am r esults and based o n the location and r ock ty pe of the g ro undw ater samples. Results show ed that ( 1) C1 w ater sam ple is po re water in lo ose str at a, and its w ater qualit y is mainly affected by disso2 lut ion, leaching, and ion ex chang e based o n PC1 and PC3 index es. The w ater ty pe is H CO3 # Cl2Ca# Mg o r Cl # H CO32Ca# Mg ; ( 2) C2 water sample is st ructur al fissure w ater, and the disso lutio n and leaching effects in C2 wat er sample ar e low er than tho se in C1 water sample based on PC1 and PC2 index es. The contents of main ions in C2 are lower than those in C1 but there are mor e car bo nat e rock and mag nesium minera l in sur ro unding ro cks, which results in the increasing of CO3- and Mg2+ contents. T he water type of C2 is H CO32Ca# M g o r H CO32Ca; and ( 3) C3 water sample is weather ing f issure water , and the dissolut ion and leaching effects in C3 w ater sample ar e ev en lower based on P C1 and PC2 index es. It has go od w ater quality but can var y sig nifi2 cantly in different seaso ns. So luble fluo rine occurs in the surr ounding ro cks, which r esults in the incr easing o f F- content. T he water type is mainly HCO3 # SO42Ca# M g.
[中图分类号]
[基金项目]
国家重点基础研究计划项目( 973 项目) ( 2010CB428805) ; 国家自然科学基金项目( 41172212)