基于模糊综合评判法的海南东北部滨海地下水水质评价

Groundwater Quality Assessment Based on Fuzzy Synthetic Evaluation to the Coastal Areas of the Northeast Hainan Island

滨海地区地下水是重要的水资源,但易受到咸潮及陆源污染物的影响;海南东北部地下水开采量逐年增加,但迄今尚无系统的水质监测与分析。运用模糊数学方法,在分析监测井地下水化学特征的基础上,构造模糊综合评价模型,对海南东北部滨海地下水水质进行评价。水化学特征分析表明:该区地下水化学类型在空间上变化较为单一,所有水样都以碱金属与强酸为主,Na+和Cl-在水中所占比重大,表明受到了咸潮的影响;水化学类型在时间上变化不明显,潮期对水化学类型并无明显影响。模糊综合评价法表明:地下水水质受到潮期影响:测井Z1大小潮时段的水质均属于Ⅱ类水;Z3大小潮时段均属于Ⅳ类;Z4大潮期属于Ⅴ类,小潮期属于Ⅳ类。总体来说,该区域地下水水质已受到海水入侵影响,不适合作为饮用水源。

The coastal area of groundwater is an important water resource,but it is easily affected by salinity and terrigenous pollutants. There are no systemic monitoring and analysis of the groundwater so far,despite the increasing exploitation year by year. Based on the analysis of chemical characteristics of groundwater monitoring results,a fuzzy synthetic evaluation model has been used to assess the groundwater quality of the Northeast of Hainan Island. The results of the analysis of chemical characteristics showed that groundwater hydrochemical types in this area is Na-Cl with no obvious change in space,indicating that groundwater is influenced by salt water. In addition,groundwater hydrochemical types did not change significantly over time,and groundwater hydrochemical types had no significant difference in tides and neap tides. The results of fuzzy synthetic evaluation also indicated that groundwater quality was affected by the tides. Groundwater quality in Z1 belonged to class II in all the time. Water quality in Z3 was classified as class Ⅳ in tides and neap tides. Water quality in Z4 was categorized into class Ⅴin tides while it is categorized into class Ⅳ in neap tides. Overall,the groundwater quality of this area was degraded by the intrusion of seawater,making it not suitable for drinking.