The analyzed results of observed precipitation and its pH in Kwangju for 262 days from Jan. 1, 1991 to Dec. 31, 1995 are as follows.
The annual mean pH was 5.7, and the monthly mean pH values of January-May and November were less than 5.6 in Kwangju. The ratio of acid rain for these periods was about 48.1 %, almost half that of the total observed days. In March, the pH was 5.4 and the ratio of acid precipitation was 69%, an especially serious situation. In the spring, the pH value was 5.5 thus weak acidic. The pH of precipitation tended to decrease with greater precipitation. The relation between persistent time and pH of precipitation is variable, but if the persistent time is long, the pH is constant and low. It is fortunate that there is an increasing trend of pH in interannual variation, but it is thought important that the amplitude of variation of pH in 1995 was high and the pH value was 4.1 in October and November. Because heavy and persistent precipitation effects the accumulation of acidity, more concern about acid rain is needed.

• Chan-Soo YOO(Department of Earth Science, Chosun University) | 류찬수