中文摘要：

降水样本中所含的离子成分和浓度能有效地反映出大气环境的污染状况。实验在乌鲁木齐市不同区域布设了降水监测点收集样品,进行数理分析,结果显示阴阳离子中SO4^2-和Ca^2＋所占比重最大,且在不同区域各阴阳离子的浓度均存在差异,从浓度分布情况来看市北区〉市中区〉市南区,从污染源分析来看,燃煤、沙尘和石油化工是影响离子浓度的主要原因。作为参照点的浓度已明显高于其他区域,建议政府部门及时调整,力求背景点监测数据的有效性。

英文摘要：

Air pollutants can be removed effectively by precipitation,and air pollution extent can be effectively reflected by the ionic composition and concentration in precipitation sample. As for this experiment,we set up three monitoring points for natural precipitation to collect samples in different districts in Urumqi,and made a mathematical analysis. The results showed that SO4^2- and Ca^2＋ occupied a large proportion of the cation and anion,and different district had the different result. By the analysis results,the concentration of ion got the maximum value in the northern part of Urumqi city,minimum value in the southern part,middle value in the central part. The spatial variation of the cation and anion was mainly resulted by urban expansion and industrial structure adjustment. From the analysis results of pollution sources,coal combustion,wind-blown sand and soil,and petrochemical industry are main contributors of atmospheric ion concentration. Ion concentration in the northern part of the city is evidently higher than any other part. Since the northern part is the reference point of the whole city,the government should take steps to keep the monitoring data of the background sites valid.