APPLICATION OF A HYDROLOGICAL & MATERIAL CYCLE SIMULATION MODEL TO REPRODUCING LONG-TERM WATER QUALITY CHANGE IN TOKYO BAY AND ITS INFLUENT RIVERS

The watershed-scale hydrological and material cycle system has deteriorated owing to the construction of various infrastructures to accommodate rapid increase of urban population and economic growth. For appropriate and efficient restoration, the entire system should be correctly understood and integrated measures should be implemented in order to build sound water and material cycles. This study attempts to develop a hydrological and material cycle simulation model for grasping water pollution processes and relationship between Tokyo Bay and its watershed. It is discussed that application of the model to understand real phenomena from the past to the present is beneficial for the investigation of water environment problems and that understanding of material outflow structure in watershed is necessary for grasping material cycle mechanism in closed water area and its watershed.