合肥环巢湖地区浅层地下水质量评价及影响因素解析

Quality Evaluation and Influence Factors Analysis of Shallow Groundwater in Chaohu Rim Region of Hefei City

利用合肥环巢湖地区城市地质调查项目取得的浅层地下水测试数据,采用单指标和综合质量相结合的方法对地下水质量进行评价。结果表明,区内浅层地下水质量一般,Ⅰ类水缺失,可直接饮用的Ⅱ和Ⅲ类水所占比例为43.85%,不能直接饮用的Ⅳ和Ⅴ类水所占比例为56.15%。分析认为区内浅层地下水质量受地质营力作用产生的原生指标和人类活动产生的次生污染指标的共同作用,一般化学指标对地下水影响程度最大,超Ⅲ类水单指标贡献率最大为亚硝酸盐,其次为硝酸盐、铁、总硬度、pH等。剔除原生异常指标外,地下水综合质量明显有所好转。

Based on the shallow groundwater test data obtained from the urban geological survey project in Chaohu rim region of Hefei,the groundwater quality is evaluated by combining single index and comprehensive quality. The results show that the quality of shallow groundwater in general is medium level; the class Ⅰ water quality is missing; the proportion of class Ⅱ and Ⅲ water quality that can be directly drunk is 43.85%,and the proportion of class IV and V water quality that can not be directly drunk is 56. 15%. By analyzing the primary index of shallow groundwater quality in human area caused by geological force,combined with secondary index of pollution produced by human activities,it is pointed out that the general chemical index has the greatest influence on the groundwater,the biggest single index of contribution rate of over class III water quality is nitrite,followed by nitrate,iron,total hardness,pH etc. The comprehensive quality of groundwater is obviously improved by eliminating the primary abnormal index.