北京西南部山前平原区地下水水质评价及其影响因素

为研究北京西南部山前平原区地下水水质状况和主要影响因素,本文以北京市丰台区为例,分别采用单因子指数评价法和模糊综合评价法对17口监测井的水质状况进行评价,并分析了空间分布规律。结果表明:丰台区地下水水质Ⅲ级以上占比为53%,未达标水质占比为47%。污染指标以总硬度、溶解性总固体、硝酸盐氮等为主,其中总硬度为水质超标最严重的指标。在空间分布上,西北山区地下水水质优于东南平原区。从自然和人为因素分析对地下水水质的影响,西北山区主要受地质条件及农业污染等影响,东南平原区主要受区域降水蒸发、工业和生活污染、地下水开采等影响。

Water quality assessment and influencing factors of groundwater in the piedmont plain area in southwest Beijing

By using the methods of single factor index evaluation and fuzzy comprehensive evaluation, the groundwater quality of a total of 17 monitoring well in the piedmont plain in southwest Beijing was evaluated and the main influencing factors were analysed. The spatial distribution pattern of groundwater quality was illustrated using the spatial analysis function of mapGIS. The resluts show that the groundwater quality classification above class III accounts for 53%,and substandard water quality accounts for 47%. The main groundwater pollution indicators are mainly composed of total hardness,total dissolved solid and nitrate nitrogen,especially the worst total hardness. In terms of spatial distribution,the groundwater quality in northwest mountainous area is better than that in southeast plain area. Considering the natural and human factors of groundwater quality, the groundwater quality in the northwest mountainous area is mainly affected by geological and agricultural pollution,whereas in the southeast it is mainly affected by regional precipitation and evaporation,industrial and domestic pollution,as weal as groundwater over abstraction.