A study on the characteristics of green infrastructure related with water circulation in existing urban area and suburban area of Tokyo Metropolitan Region and perspectives for Metropolitan Planning

The purpose of this paper is to clarify the characteristics of green infrastructure in existing urban area and suburban area in Tokyo Metropolitan Region, towards the sustainability of water circulation based on the watershed analysis. The following things have clarified. By introducing Natural land use unit, it becomes clear that Yato Unit, which is the complexed system of hilly land and narrow valley, takes the important roles on the permeability and storage of the rainfall. The distribution of Yato Unit has analyzed and these areas identified as the essential matrix of water circulation. The second is the potential areas of the rain-water storage have clarified based on the analysis of rice field and wet land, and identified as the matrix of water storage. The third is core areas of the water circulation have identified by combining Natural land use unit, various strategies and laws. These areas are regarded as the high priority areas which should be registered as the protection site. The fourth is the importance of springs as cultural landscape has clarified. Based on the above founding, it becomes possible to establish the structure of Metropolitan Water Circulation Green Infrastructure Planning for achieving the sustainable region.