Evaluation of urban non-point pollution load by a distributed model considering roofs and roads as impervious surface

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1. Development and validation of a non -point pollution load model considering roofs and roads as impervious surfaceRoofs and roads were considered in a non-point pollution load model as impervious surface. The importance of their different runoff characteristics was recognized in order to explain dynamic runoff behavior in an area with a separate sewer system. The runoff behavior of suspended solids was evaluated separately in two size fractions (l.2〜45μm and 45μm〜2mm). In order to fit the model simulation to the observed data, the concept of critical runoff rate for wash-off was introduced into the Sartor and Boyd model for explaining the different runoff behavior of fine and coarse particles. The simulated results with the modified Sartor and Boyd model agreed satisfactorily with the observed data for a series of seven rainfall events with weak rainfall intensities.To improve the model for better fitting of runoff behavior in heavy rains, wash-off models from pervious area were addi … More tionally proposed. Introduction of the wash-off functions for previous surface as well as the modified Sartor and Boyd model for impervious surface, the simulation results could agree with the observed data even in the heavy rainfall events.A method was developed for estimation of the fractions of roof and road surfaces in target drainages. The detailed land use data given in 10m grid basis was utilized to estimate their fractions. Once the roof and road surface fractions were given, it became easy to determine the runoff parameter values. The validity of the method was confirmed in four cities.2. Characterization of micropollutants in the dust of roof and roadPolycyclic aromatic hydrocarbons on the dust of roof and road were analyzed. The result of cluster analysis based on the profiles of the micropollutants showed a clear difference between road dust and roof dust in a district. But in the case of comparing the two districts having different pollution loading from non-traffic pollutant sources, the charasteristics of the micropollutant profile was depending much more on the characteristics of the district than the surface property. Less