Impact of green infrastructure creation scenarios on the periphery of metropolitan areas on inland flood control effects: A Case Study of the Upper Reaches of Tatsuta River

Strategic conservation and creation of green infrastructure that targets not only river areas but also entire watersheds, including watersheds and flood areas, is attracting attention, as is the control of land use in watershed areas that catch rainfall, as well as the infiltration and storage of rainwater. This study focuses on the upper Tatsuta River basin in Ikoma City as a case study and employs scenario analysis to evaluate the effectiveness of green infrastructure of various locations and qualities to reduce flood risk under population decline. The findings reveal that different forms of green infrastructure exhibit different levels of flood mitigation, with annular GI being effective in the majority of evaluations. These conclusions are expected to provide knowledge toward the creation of GI in peripheral areas of metropolitan areas, including Ikoma City.