丽江市降水中常量离子的化学特征

CHEMICAL CHARACTERISTICS ON MAJOR IONS OF RAINWATER IN LIJIANG CITY

运用相关分析、因子分析、趋势分析、海盐示踪法和HYSPLIT模型,对1989—2006年期间丽江市降水中常量离子的化学特征分析表明,该区降水中常量离子浓度为SO42-(Ca2+(Cl-(NO3-(K+(Mg2+(Na+,其中SO24-和Ca2+是降水中高浓度离子,分别占总离子浓度的43.9%和32.1%,降水中阴离子总浓度显著高于阳离子总浓度,由于离子在大气中的化学反应和来源的一致性,离子间相关性水平较好,特别是K+,Mg2+,Ca2+与NO3-和SO24-.离子浓度的年际变化与丽江市产业结构的变化关系密切.研究区大气降水中离子主要是陆源物质贡献,NO3-,SO42-,K+,Ca2+,Mg2+和Cl-陆源物质贡献比例依次为100%,98.4%,98.4%,99.8%,92.4%和83.4%.

Rainwater samples were colleted from1989 to 2006 in Lijiang city. Rainwater chemical characteristics were studied, using HYSPLIT model, ions tracer techniques, factor analysis, correlation and trend analysis. It is indicated that the total ionic concentration was dominated by SO4^2- and Ca^2＋ , and account for 43.9% and 32. 1% of total ionic concentration. Sort order of ions concentration is SO4^2-〉Ca^2＋〉Cl^-〉NO3^-〉K^＋〉Mg^2＋〉Na^＋. The total anions concentration is higher than the total cations concentration. The correlation among ions is significant due to the atmospheric chemical process, especially K^＋,Mg^2＋,Ca^2＋and NO3^-,SO4^2- Variation of ionic concentrations closely interrelated to the change of industrial structure from 1989 to 2006 in Lijiang city. Ions mainly origin from land dust, and the non-marine source percent of NO3^-,SO4^2-,K^＋,Ca^2＋,Mg^2＋ and Cl^- is 100%, 98.4%, 98.4%, 99. 8%, 92.4% and 83.4%, respectively.