| Title |
Characteristics of Road Runoff depending on the Rainfall Intensity |
| Authors |
김석구 ( Seog Ku Kim ) ; 김영임 ( Young Im Kim ) ; 윤상린 ( Sang Leen Yun ) ; 이용재 ( Yong Jae Lee ) ; 김이호 ( Ree Ho Kim ) ; 김종오 ( Jong Oh Kim ) |
| Keywords |
First rainfall; Road runoff; Rain intensity; First flush effect |
| Abstract |
Growth in population and urbanization has progressively increased the loadings of pollutants from non-point sources as well as point sources. Therefore, it is necessary to manage both point and non-point sources contaminations for protecting water environment and improving water quality. This study investigated the characteristics of pollutant release over a wide range of rainfall intensities as a requisite to control road runoff that accounts for the largest portion of non-point source contamination in urban areas. Samples of runoff rainwater collected from real road surfaces were analyzed for physicochemical parameters such as pH, suspended solids, and heavy metals. A experimental model road (30cm×30cm) was also used to evaluate wash-off properties of pollutants deposited on the surface as functions of time and rainfall intensity. Analysis of runoff samples on rain events showed that the pollutant wash-off patterns for heavy metal and suspended solids were similar. This implies that the particles in rainwater adsorb heavy metals. Experiments using the model road made of impervious asphalt demonstrate a strong first flush phenomenon. At high rainfall intensity, approximately 80% of total pollutants were released within 15 min. The pollutant wash-off rates rapidly increase from 9 ㎜/hr to 12 ㎜/hr of rainfall intensity and decrease over 12 ㎜/hr of rainfall intensity. |