气象因子对杭州市区酸雨的影响

Influence of Meteorological Factors on Acid Rain in Hangzhou

利用1996—2010年杭州市区酸雨及环境气象因子观测资料,分析了近15年来气象因子对杭州市区酸雨的影响。结果表明:强降水下的酸雨出现频率较低,而pH低值多出现在连续阴雨的天气;北风及偏北风下的降水pH均值较低,西偏南风下降水pH均值较高;在高压底部型天气下降水pH均值最低(4.51),同时酸雨出现频率高达85.3%;而雷雨天气下pH均值最高(5.11),酸雨出现频率最低(66.5%)。由此可知在不同的天气类型下,污染物扩散、稀释和湿沉降情况不同,可能是导致酸雨污染程度不同的主要原因之一。

The influence of meteorological factors on acid rains is investigated on the basis of observation data on acid rains and environmental meteorological factors from the urban area of Hangzhou from 1996 to 2010. The research indicates that the low incidence of acid rains occurred under heavy precipitation weather, the lower pH value was more likely to happen in continuous rainy weather. The average pH of rainwater was low under north wind conditions, and high under southwest winds. The pH value of precipitation was as low as 4.51 and the incidence of acid rain was up to 85.3% under the control of high- pressure in Hangzhou; the pH value peaked 5.11 and the lowest acid rain rate was 66.5% in thunderstorm weather. The results show that different weather types led to varying degrees of pollutant diffusion, dilution, and wet deposition, which are also the main reasons for acid rain pollution.