丽水小盆地型城市酸雨现状及成因分析

根据浙江省丽水市 1 986— 2 0 0 2年酸雨监测数据 ,对该市酸雨污染的现状特征及成因进行了分析。结果表明 ,丽水市酸雨污染严重 ,并呈逐年加重的趋势。冬、春季酸雨率高 ,降水 pH值低 ;降水的主要离子SO42 -与NO-3比值逐年下降 ,说明大气污染有从煤烟型转为煤烟型与机动车尾气混合型的趋势 ;煤耗量、地型地貌特点、低空逆温层频率、地面弱风频率对酸雨率和降水 pH值有明显的影响。

Present status and cause of formation of acid precipitation in the small basin city of Lishui

Based on the monitoring data from 1986 to 2002,it is found that Lishui City is suffering heavily from acid precipitation and the situation tends to become more and more serious.The acid precipitation is characterized by high frequency of occurrence in spring and winter,low pH value,and decreasing ratio of SO_4(2-)/ NO-_3,which indicates that the source of air pollution is changing from coal burning to a mixture of coal burning and automobile emission.Coal consumption rate,topographic features,frequency of the appearance of low altitude inversion layers and frequency of surface weak winds are found to have significant effects on acid precipitation and pH value of the rain.