The Characteristics of Long-Term Variation of Acid Deposition in Korea

초록

We looked into the characteristics and long term variations of chemicals affecting the acidity of precipitation. To this end, we analyzed the data collected at three acid deposition monitoring sites for the period from 1999to 2013. Three monitoring sites include Seoul, Taean, and Jeju island. Required parameters such as pH, electricconductivity(EC), and concentrations of eight major ionic species were measured. In order to assure accuracyand precision of the data, values of measured electric conductivity were compared against values of calculatedelectric conductivity. Moreover, comparison between and was made in accordance with EANET°Øs QA/QCmethod to assure data reliability. During the monitoring period, the deposition was slightly acidic with pHvalue ranging between 4.6 and 4.9. Precipitation with pH 4.1 to 4.5 was most frequently observed with occurrencefrequency of 27%. The analysis of seasonal variations of atmospheric concentration of pH showed thatpH level was highest in spring season due to the influx of yellow sand and high pH levels in soils. The studyalso found that pH levels of samples collected at Seoul and Taean monitoring sites were lowest in autumn. Onthe other hand, pH level in Jeju was lowest in winter season. Increase in concentrations of NO 3-in precipitationwas commonly observed at three monitoring sites. The concentrations of NO 3-and NH 4+which affect the acidityof precipitation at Seoul and Taean monitoring sites showed increasing trend.

키워드