沧州西部地区浅层地下水水化学特征及水质评价

摘要

Based on the theory of membership degree and comprehensive evaluation in the Fuzzy mathematics, 15 groundwater samples from west of Cangzhou were collected and assessed. Through the analysis of water quality and the local pollution characteristics, chloride, sulfate, nitrate nitro-gen, total dissolved solids, total hardness were selected to be the evaluation index system. And the value of the corresponding indexes of 5 grades in the national water quality standard was the compre-hensive evaluation level in this study. On this basis, the membership degrees of the groundwater sam-ples in the 5 grades were calculated and by using the maximum membership principle, the groundwa-ter grade of each samples were determined. The results show that the groundwater quality in this area is poor generally. Only 53. 7% of the samples measure up the standard of grade III and the six sam-ples beyond it were all caused by the chloride or total hardness which was brought by seawater intru-sion and human activities.%利用模糊数学中隶属函数及综合评判的计算、分析原理,对沧州西部地区浅层的15组地下水水质进行了综合评价。水样的采集深度集中在15~25 m之间,含水层均为第四系松散沉积层。选定评价指标体系为氯化物、硫酸盐、硝酸盐氮、溶解性总固体以及总硬度,国家地下水水质标准的5个等级中相应指标值作为综合评判级。计算方法为：计算各水样点分别在5个等级中的隶属度,利用最大隶属原则,判定各水样所在等级。同时,根据评价的等级结合相应地下水样本的水化学特征、污染特征等对研究区的地下水进行综合评价和分析。评价结果显示,研究区浅层地下水已经受到了比较严重的污染,符合集体式饮用水源及工农业用水水质标准( III级及III级以上)的样本仅占总样本的53．7%,Ⅴ级样本占23%,主要水化学类型为氯化钠型水。海水入侵以及人类活动为影响该区域浅层地下水水质的主要因素。