运用相关分析、趋势分析、海盐示踪法和HYSPLIT模型,对2006-05—23~2006-07—02云南丽江市夏季降水常量离子的化学特征分析表明,降水中离子浓度的大小顺序为SO4^2-〉Ca^2+〉Cl^-〉NO3^-〉Na^+〉K^+〉Mg^2+,其中XO4^2-和Ca^2+是夏季降水中的高浓度离子,分别占离子总浓度的65.5%和15.6%;13次降水中阴离子总浓度显著高于阳离子总浓度.夏季降水中SO4^2-:NO3^-变化范围为7.2~37.1,平均值为15.7,表明SO4^2-为该区降水酸度的主要贡献者.由于离子在大气中的相互反应和来源的相似性,离子间相关性水平较好,其中SO4^2-和NO3^-的相关系数为0.74;离子浓度与同期降水和平均风速表现负相关.研究区夏季降水中NO3^-、SO4^2-、K^+、Ca^2+主要是陆源物质输入,NO3^-、SO4^2-、K^+、Ca^2+、Mg^2+和Cl^-陆源物质贡献比例依次为100%、98.8%、96%、99.3%、46.7%和50.3%.人类经济活动导致的一些污染是该区大气环境变化的主要原因;丽江周边工业区的污染物质主要通过局地环流输入,南亚、东南亚和我国东南沿海工业区的污染物质主要随季风环流输入.
Rainwater samples were colleted from Lijiang City, China, in 23 May-2 July, 2006. Rainwater chemical compositions and sources were studied, using HYSPLIT model, ions tracer techniques, correlation and trend analysis. Total ionic concentration was dominated by SO4^2- and Ca^2+ , which account for 65.5% and 15.6% respectively. Sort order of ions concentration is SO4^2- 〉 Ca^2+ 〉 Cl^- 〉 NO3^- 〉 Na^+ 〉 K^+ 〉 Mg^2+ . Total anions concentration is higher than total cations concentration in 13 rainwater events. The ratio of SO4^2- to NO3^- varies from 7.2 to 37.1 and average value is 15.7, it reflected SO4^2- made great contribution to rainwater acidity in Lijiang City. The correlation among ions is significant due to the atmospheric chemical process and similar ionic sources, and correlation coefficient between SO4^2- and NO3^- is 0.74. And what' s more, the negative correlation of ionic concentration, precipitation and the average wind speed is also outstanding. The source of NO3^- , SO4^2- , K^+ and Ca^2+ is mainly land dust, and the non-marine source percent of NO3^- , SO4^2- , K^+ , Ca^2+ , Mg^2+ and Cl^- is 100%, 98.8%, 96%, 99.3%, 46.7% and 50.3%, respectively. The main reason of atmospheric environmental variation in Lijing City is pollution caused by economic actions. The pollutants from surrounding industrial parks input into Lijiang City by local circulation, and from industrial regions of Southern Asia, Southeastern Asia and Southeastern China input into Lijiang City by monsoonal circulation.