Long Term Monitoring of Storm Surface Runoff from Urban Pavement Road in Korea

Abstract

Long term monitoring was conducted to investigate a surface runoff of pollution from urban highway. The monitoring data was collected for 18 rainfall events and was used to correlate pollution load to various parameters, such as rainfall intensity, antecedent dry days and total discharge flow. Runoff coefficient and seasonal variation were also evaluated. The mean runoff coefficient of the highway was 0.823(range; 0.4687~0.9884), and wash-off ratio for CODMn and SS loads was 72.6% and 64.3%, respectively. For the initial rainfall event, the runoff EMC of CODMn was high in summer and the EMC of SS was high in autumn season. However the seasonal variation of T-N and T-P was not significant. The discharged CODMn-EMC was 147.6 mg/L~9.0 mg/L on the generated CODMn-EMC of 98.8 mg/L~8.9 mg/L. While the generated EMC of SS was in 285.7 mg/L~20.0 mg/L and its discharged EMC was in 190.4 mg/L~8.0 mg/L. EMC of pollutants was not directly related to the first flush rainfall intensity and the antecedent dry days. But the correlation was relatively high between EMC and cumulative runoff flow volume. The trend of EMC was reduced with the cumulative runoff flow volume.