Pollution characterization of urban stormwater runoff on different underlying surface conditions.

Based on monitoring the runoff water quality on different underlying surface conditions in Beijing and analyzing the experiment data via Pearson statistical method, the paper covered the time-varying regularity of stormwater runoff pollutants and the even mean concentrations (EMCs) of stormwater runoff pollutants. Major factors for runoff water quality were also analyzed. The results showed that compared with asphalt road and bituminous roof, the green roof had lower flush effect, playing an important role in reducing the concentration of runoff pollutants. The initial EMCs values of COD, NH3-N, NO3-N and TP were higher than the fifth category of national surface water standard. Parts of them were even beyond the third category of emission discharge standard. The values of EMCs were positively correlated with dry weather deposits and runoff duration, and negatively correlated with precipitation and rainfall intensity. The analysis indicated that the controlling preliminary runoff pollution and surface clean-up can reduce the urban rainfall runoff pollution.