肥城盆地区域地下水化学特征及水质评价

Evaluation on Chemical Characteristics and Water Quality of Groundwater in Feicheng Basin

摘要:

为了解肥城市地下水水化学特征及水质状况，选取20个地下水水质分析数据，综合运用统计分析、Piper三线图，Gibbs图及离子比值等水化学方法，分析了地下水水化学特征，基于模糊综合评价法，对地下水进行了质量评价。结果表明，研究区地下水中阳离子以Ca2+,Mg2+为主，阴离子则以HCO3，NO3，SO24为主，阴、阳离子分别存在HCO3＞NO3＞SO24＞Cl和Ca2+＞Mg2+＞Na+＞K+的关系。TDS介于325.0~1720.0mg/L之间，均值为741.55mg/L。地下水呈弱碱性，且属高硬水。地下水化学类型以HCO3Ca，HCO3·SO4Ca为主，水岩作用是地下水水化学组分的主要控制因素，主要受碳酸盐岩的风化溶解控制。研究区地下水以Ⅱ，Ⅲ类水为主，占65%，但Ⅴ类水所占比重也较大，占到了35%。

Abstract:

In order to understand hydrochemical characteristics and water quality of groundwater in Feicheng city, selecting groundwater quality analysis data of 20 samples in 2017, by uisng statistical analysis, Piper trilinear diagram, Gibbs diagram and ions ratio, hydrochemical characteristics of groundwater have been analyzed, and the quality of groundwater has been evaluated based on the fuzzy comprehensive evaluation method. It is showed that Ca2+ and Mg2+ are main cations in groundwater, while HCO3, NO3 and SO24 are main anions. There relationships between HCO3>NO3>SO24>Cl and Ca2+>Mg2+>Na+>K+ exist in anions and cations, respectively. The value of TDS ranges from 325.00 to 1720.00 mg/L, and the average value is 741.55mg/L. Groundwater is weak alkaline and belongs to high hard water. Hydrochemical types of groundwater are mainly HCO3Ca and HCO3SO4Ca. Waterrock interaction is the main controlling factor of groundwater hydrochemical composition, which is mainly controlled by dissolution and weathering of carbonate rocks. Based on the method of fuzzy comprehensive evaluation, it is concluded that the groundwater in the study area is mainly of type Ⅱand Ⅲwater, and account for 65%, but the proportion of type Ⅴwater is also large and accounts for 35%.