盐池内流区某气田地下水化学特征及水质评价

摘要

Water chemistry data of 27 shallow groundwater samples taken from a gas field of the inner flow Area in Yanchi was analyzed firstly and then graphic method and mathematical statistic method were introduced to analyze the chemical characteristics of shallow groundwater in the area, on the basis of which the status of water quality of shallow groundwater in the area was evaluated by using fuzzy comprehensive evaluation method. The results show that shallow groundwater of the researched area in general is alkaline, great hardness and brackish water, and that F⁃level is widely high in groundwater. Major components of shallow groundwater are Na+, SO2-4 , HCO-3 and Cl-, and major hydrochemical types are Cl⁃Na and SO4⁃Na. 78% of the shallow groundwater samples belong to classⅣandⅤwater. Water quality is poor overall in the study area, which is associated with groundwater flow conditions and primary geochemical environment. The study area lacks water resources because of the poor water quality, so measures should be taken to protect the little remaining groundwater resources of high quality.%在对盐池内流区某气田浅层地下水27个取样点水质监测数据分析的基础上，运用图解法及数理统计方法对该区浅层地下水的水化学特征进行了分析，并在此基础上采用模糊综合评价法对该区浅层地下水进行了水质评价。结果表明：研究区浅层地下水总体偏碱性，硬度极大，属于微咸水，地下水中F－含量普遍偏高；研究区浅层地下水主要组分为Na＋、SO2－4、HCO－3和Cl－，水化学类型以Cl⁃Na型和SO4⁃Na型为主；研究区水质总体较差，浅层地下水水质78％属于Ⅳ类和Ⅴ类，主要与地下水径流条件及原生地球化学环境有关；研究区属于水质性缺水区，应采取措施防止地下水污染，保护有限的优质地下水资源。