高山、海岛及城市降水污染研究

A STUDY OF PRECIPITATION POLLUTION OVER MOUNTAIN, ISLAND AND CITY AREAS

本文通过对1988～1989年在福建九仙山、平潭岛、福州市所作降水pH值同步观测。结果表明:在连续性降水方面九仙山pH值属中性;平潭岛pH=4.49,酸雨率为57.7%,约1/10强酸雨出现;福州pH=4.25,酸雨率为89.4%,约有1/3强酸雨出现。分析认为,降水pH值的大小主要取决于当地的污染状况,并且与天气背景及气象条件有密切关系。

During 1988-1989, a synchronus observations of the pH values of precipitation were taken at stations of Jiuxian Mountain (1650 m a. s. l.), Pingtan Island(32.5m) and Fuzhou City(83.8m) in Fujian Province. The result shows that: (1) Over Jiuxian Mountain, the pH value of serial precipitation varies from 5.00 to 7.00, the average pH value is nearly neutral (pH=5.90), the rate of acid rain is 10%; for Pingtan Island, the pH value varies from 3.43 to 7.15 with an average of 4.49. The acid rain rate is 57.7% and 10% for strong acid rain; for Fuzhou City, the pH value varies from 3.30 to 6.99 with a mean of 4.25, the acid rain rate is 89.4% and 33.3% for strong acid rain. (2) The pH values of precipitation are mainly determined by the local pollution condition. With the increment of the city population density and the development of city industry, the acid rain frequency increases and the pH mean value decreases. (3) The pH magnitude of precipitation is closely related to the pollution condition in connection with wind direction and weather condition over observational station. If the station is controlled by stationary front or cold front, acid rain is serious and its frequency increases, if controlled by high pressure, the frequency of acid rain decreases.