Runoff Characteristics of Non-point Pollutants Source in Suwon City

Abstract This study was to investigate the runoff characteristics of non-point pollutants source at the urban area in Suwon city. The highest T-N and T-P concentration of rainfall runoff observed in agricultural area. In residential area, the highest BOD 5 and SS concentration of rainfall runoff was investigated. During rainfall events, the peak concentrations of SS and BOD 5 were observed after 1~2 hours of rainfall in urban area. Whereas, the peak concentrations occurred within 1~2 hours after rainfall and then the highest concentrations of SS and BOD 5 sharply decreased, showing strong first flush effect in urban area. The EMC results indicated that the highest value of T-N and T-P in agricultural area was observed. While residential area was shown the lowest EMC value as T-N and T-P. Non-point pollutant loads on the land use types in urban area were investigated in the order of residential>industrial>agricultural>highway. BOD 5 and SS loads on urban watershed were investigated in the order of Suwon>Hwangguji>Seoho>Wonchunri. Whereas, T-N and T-P loads on urban watershed were investigated in the order of Hwangguji>Suwon>Wonchunri>Seho. Key words: Non-point pollutants source, EMC, First flush effect, Land use types, Loads