东天山哈密榆树沟流域夏季降水的化学特征  

Chemical Properties of Summer Precipitation in the Yushugou River Basin in the East Tianshan Mountains

作　　者：王晓艳[1] 蒋缠文[1] WANG Xiao-yan;JIANG Chan-wen(College of Chemistry and Environment Sciences, Weinan Normal University~Key Laboratory for Ecology and Environment of River Wetlands in Shanxi Province, Weinan 714000, Shanxi, China)

机构地区：[1]陕西省河流湿地生态环境重点实验室/渭南师范学院化学与环境学院

出　　处：《干旱区研究》2018年第2期277-286,共10页Arid Zone Research

基　　金：国家重大科学研究计划项目(超级973项目)(2013CBA01801);陕西省自然科学基础研究计划(2017JQ6080);陕西省高校科协青年人才托举计划项目(20170303);陕西省教育厅重点项目(17JS038);渭南市创新团队专项计划(2015TCTD-2)资助

摘　　要：2013年5—8月按照GB13580.2-92规定的大气降水采样方法,采集了东天山喀尔力克山南坡榆树沟流域32场降水,进行了p H、EC及离子组成的测定,并运用综合描述法、相关性分析、气团来源轨迹、富集因子及端源贡献法探究其来源。结果表明：榆树沟流域夏季降水的p H平均值为6.8,呈弱酸性;电导率在3.79239μs·cm-1,受降水量影响明显;阴阳离子质量浓度的平均值分别是SO42-〉NO3-〉Cl-〉F-和Ca2＋〉NH4＋〉Na＋〉K＋〉Mg2＋;SO42-、NO3-、F-和NH4＋主要来自于人类活动;Cl-基本来自海盐源,受地壳源的影响甚微;Na＋的来源受海盐源和陆源共同影响;Ca2＋和K＋来自于非海盐源的贡献。As an effective means to study the change of atmospheric chemical composition,atmospheric precipitation chemistry could accurately reflect the local atmospheric environmental quality and air pollution. The precipitation chemical properties far away from human colonies can reflect the background value of atmospheric chemistry,and can also help us to study the atmosphere chemical conversion,transmission and the formation process and mechanism of acid rain. Restricted by the seasonal precipitation distribution and the observation conditions in drainage basin,the p H value,EC and ion composition in precipitation in the Yushugou River Basin in the east Tianshan Mountains from May to August 2013 were analyzed. The ionic sources were simultaneously investigated. The results showed that precipitation was neutral with mean p H value of 6. 8. It suggested that there was no acid rain during the sampling period in the study area. The EC was in a range of 3. 79-239 μs·cm-1,and it was obviously affected by precipitation. With the increase of rainfall,the under cloud wash action diluted the conductive ions in precipitation,and the precipitation conductivity decreased correspondingly. The concentrations of cations and anions were in the orders of Ca2＋〉 NH4＋〉 Na＋〉 K＋〉 Mg2＋and SO42-〉 NO3-〉 Cl-〉 F- respectively. The cationic order was exactly the same as that of the elements in crust and different from that of cation concentration in seawater（ Na＋〉Mg2＋〉 Ca2＋〉 K＋）. It may be due to the geographic location. The Yushugou River Basin is located in an arid area where large deserts are distributed. The SO42-/NO3- ratio（ 1. 76） indicated that SO42- was the main acid-causing substance in precipitation. The sources of the different ions in summer precipitation were different. SO42-,NO3-,F- and NH4＋ came mainly from man-made sources,such as coal burning,vehicle emission and agricultural production activities. Cl-almost came from the sea salt source and crust source. The sodium concentration w

关 键 词：大气降水 化学特征 离子来源 气团轨迹 榆树沟流域 东天山 

分 类 号：P426.612[天文地球—大气科学及气象学]