江西省酸雨变化特征及其与气象条件的关系

VARIATION CHARACTERISTICS OF ACID RAIN IN JIANGXI AND ITS RELATIONSHIP WITH METEOROLOGICAL CONDITION

利用江西省气象部门12个酸雨监测站2007—2011年的观测资料,分析了江西省酸雨的时空分布特征。结果表明,近年来江西省酸雨污染总体上有缓和趋势。夏半年酸雨污染较轻,其中8月的污染最轻;冬半年酸雨污染较重,其中1月的污染最为严重。整个江西省都受到酸雨污染的威胁,但污染程度分布不均,江西中西部的吉安、宜春以及东北部的景德镇污染较为严重,江西中东部的鹰潭、上饶以及西部的萍乡污染较轻。通过对酸雨与气象条件的关系分析发现,江西省降雨的pH值随降雨量的增加先减小再增大,小雨、中雨和大雨的pH值较小,而暴雨和大暴雨的pH值较大。850 hPa层为北风(N)、东北偏北风(NNE)、东北风(NE)或东北偏东风(ENE)(总方向角为348.75°—78.75°)时,南昌降雨pH值较高,东南偏东风(ESE)时南昌降雨的pH值较低;850 hPa层为东风时赣州降雨的pH值较高,北风(N)时赣州降雨的pH值较低。

With the 2007--2011 acid rain observation data of 12 stations in Jiangxi, this paper analyzes the temporal and spatial characteristics of acid rain in Jiangxi province. The result shows that the acid rain pollution appears decreasing trend in Jiangxi over recent years. The acid rain pollution is milder in summer （especially in August）, while it is heavier in winter （especially in January）. Heavier acid rain pollutions occur in Yichun, Ji＇an and Jingdezhen, while milder ones occur in Yintan, Shangrao and Pingxiang. This paper also investigates the relationships between acid rain and meteorological conditions. It is found that the precipitation pH value decreases at first and then increases with the rainfall increase, the precipitation pH value of heavy rain is significant larger than that of moderate rain. When 850 hPa wind direction is among 348.75°--78.75°, the precipitation pH value in Nanchang is larger, while when 850 hPa wind direction is among 112.5°, the precipitation pH value in Nanchang is smaller. Ganzhou presents larger precipitation pH value under 850 hPa easterly, while it is smaller under 850 hPa northerly.