Hydrochemical Characteristics and Water Quality Assessment of Groundwater in Daxing District of Beijing, China

摘要

Based on the groundwater samples collected in Daxing District of Beijing in June and October 2008, the groundwater quality is assessed and the groundwater hydrochemical characteristics are analyzed. The assessment of groundwater quality is conducted by using the F-value comprehensive assessment method, and GIS approach is used to obtain the zonation of groundwater quality. The results show that the groundwater quality is classified into II, III and IV class, and the groundwater quality gradually changes well from north to south. The groundwater of IV class is located in the northern part, which accounts for about 40% of the total area, and the major pollution factors are TDS and nitrate. The groundwater is mainly characterized by HCO_3-Ca·Mg type. The concentrations of (SO_4)~(2-), (NO_3)~-, Ca~(2+) and TDS follow a decreasing trend generally from north to south, all of which have slight seasonal changes. Both natural factors and human activities have impacts on the chemical composition of the groundwater. The protection of groundwater environment in northern Daxing should be taken more seriously.