Pollutant Flushing Characterizations of Stormwater Runoff and Their Correlation with Land Use in a Rapidly Urbanizing Watershed

In this study, pollutant flushing characterizations of stormwater runoff were analyzed in a rapidly urbanizing area based on field monitoring. The results showed that both imperviousness and rainfall intensity have a positive impact on first flush effect. Significant end flush effect exists in rapidly urbanizing areas and it occurs more frequently than first flush effect under the condition of high proportion of agricultural land use and light rainfall intensity. Compared to urban areas, first flush effect is relatively weak and end flush effect is relatively strong in rapidly urbanizing areas. BMPs based on first flush concept should be carefully applied in watershed with strong end flush effect and weak first flush effect.