Abstract
A simulation model is presented to describe water quality in a river flowing through an urban area. The model is composed of a submodel calculating the non-uniform flow and a diffusion submodel. The diffusion submodel can describe a variation of particulate and dissolved BOD, SS and dissolved oxygen. The application of this model to the Kaki River at Nagaoka showed a successful representation of water quality in the river at the present state. Furthermore, the effect of wastewater BOD removalin the future was examined. The results showed a remarkable improvement of water quality by arranging the sewage treatment system.
