京津地区酸雨变化特征及趋势分析

Trend Analysis of Acid Rain Pollution in Beijing-Tianjin Area

利用京津地区三个国家级酸雨观测站(北京昌平、上甸子和天津站)1993-2006年的酸雨资料,研究了京津地区酸雨空间分布及其季节特征,并利用M-K统计分析方法研究了其变化趋势。结果表明:京津地区的大气降水pH值有明显的季节变化特征,三个站点在冬季、春季和初夏基本一致,酸雨频率秋冬高,而春季和初夏低。但三个站点的大气降水、pH值和酸雨频率变化趋势差异显著。其中天津站在1990年代初较为严重,但14年间天津站酸雨状况有改善的趋势。昌平站降水pH值的M-K统计量为-3.17,说明1993-2006年昌平站降水酸化趋势显著,并通过了95%的置信度显著性检验。上甸子站代表了京津的郊区,2002年以前酸雨状况有所改善,2002年以后酸雨状况日趋严重。

The spatial and seasonal variation characteristics are discussed by using the data at three monitoring stations from 1993 to 2006 in Beijing and Tianjin.The Mann-Kendall trend test was applied to examine the trend of acid rain in recent 14 years.The results show that three stations have some resembling characteristics,such as high level of pH value in autumn and winter,low level of pH value in spring and summer.However,the changing trend of three stations is very different.The acid rain frequency at Tianjin Station is serious at the beginning of the 1990s,but the state of acid rain has improved obviously recently.On the other hand,the value of M-K method in Changping Station is-3.17,indicating that the state of acid rain has deteriorated obviously during the last 14 years.As the suburb of Beijing,Shangdianzi Station was improved before 2002,but afterwards the state of acid rain has become increasingly serious.