云南思茅地区近20年(1993—2012)酸雨及酸沉降量变化规律  

Temporal trends of acid rain and acid deposition in south Yunnan: 1993—2012

作　　者：韦霞[1] 潘月鹏[2] 竺夏英[3] 谢雨竹 王丙春[1] 罗庆仙 

机构地区：[1]云南省气象局,昆明650000 [2]中国科学院大气物理研究所大气边界层物理和大气化学国家重点实验室,北京100029 [3]国家气候中心,北京100081 [4]成都信息工程学院,成都610225 [5]普洱市气象局,普洱665000

出　　处：《环境化学》2014年第8期1361-1365,共5页Environmental Chemistry

基　　金：国家重点基础研究发展规划(973)项目(2012CB417101);云南省"三农"气象服务综合能力建设项目资助

摘　　要：统计分析了云南思茅地区1993—2012年间采集的2533次降水样品,发现酸雨(pH<5.60)频率为46%(n=1160),强酸雨(pH<4.50)发生频率为10%(n=248).过去20年强酸雨发生频率的变化以2003年为界分为前后2个阶段,每个阶段都出现先升后降的变化趋势,而雨量加权年平均pH值长期变化规律基本与此相反.除2003、2004和2012年外,其他年份雨量加权平均pH值均低于5.60,表明思茅降水酸化严重.降水电导率与云南SO2排放量的历史变化具有一致性,即2006年以前持续增加,之后缓慢下降,表明人类活动对降水污染有重要影响.而酸雨频率的年际变化与降水量基本一致,但与电导率不一致,表明思茅酸雨年际变化规律主要受降水量影响,而与污染物排放关系不明显.同时,降水量也显著影响了思茅酸沉降量的年际变化(范围:1.3—70 meq·m-2·a-1).随着南亚夏季风减弱,思茅降水量减少,这将导致酸沉降量降低,但酸沉降量的变化对生态系统的长期影响亟待评估.In this study, Simao, a typical area in Yunnan Province, was selected to examine the temporal trend of acid rain and acid deposition. From 1993 to 2012, 2533 precipitation samples were collected at this site. Of these samples, 46% （ n=1160） were found to be acid rain （ with pH＆lt;5？60） , particularly 10% （ n=248） were strong acid rain （ with pH ＆lt;4.50） . Over the past 20 years strong acid rain showed similar pattern either before or after 2003, that is, increasing first then decreasing. Most of the volume-weighted-average of the annual rainfall pH was lower than 5. 60, indicating the risk of acidification. The temporal change of the precipitation conductivity was consistent with that of SO2 emissions in Yunnan, which continued to increase until 2006, followed by a slow decline. The agreement of the inter-annual variability of acid rain and precipitation, but not the conductivity, indicated that the inter-annual variation of the acid rain was affected more significantly by precipitation rather than the anthropogenic emissions. The precipitation also played an important role in the annual variation of acid deposition flux （ range： 1. 3-70 meq·m-2·a-1 ） . With the declining trend of South Asian summer monsoon, drought in Yunnan will lead to the decreasing amount of acid deposition, but long-term effects of acid deposition on the ecosystem needs further attention.

关 键 词：酸雨 气象因素 历史变化 酸沉降 云南 

分 类 号：X517[环境科学与工程—环境工程]