Case studies of adaptation cities

Abstract This chapter introduces implementation examples and future visions in Osaka as a city where mitigation measures for heat island countermeasures are deployed. Osaka is the second largest city in Japan after Tokyo. In Section 1, first, we will introduce “Cool Spot 100 Selections” selected by citizens in Osaka Prefecture in 2012 as an example of an outdoor space that can reduce the unpleasant heat of urban areas due to the heat island phenomenon and make it comfortable. Next, we will introduce 100 cool roads that connect these cool spots selected by the citizens of Osaka in 2015. In further sections, examples of environmental elements used for mitigation measures against heat island will be introduced, using “water,” “green shade,” and “wind blowing along the river” as representative elements. In addition, the ideas for the future development using these elements will be introduced. Water is a very attractive substance as a heat transport medium. Section 2 introduces two heat island mitigation measures using water. The first is the improvement of microclimate in the city by artificial water facilities that actively use the evaporation effect of water. The second is the reduction of atmospheric heat load in business districts of large cities by introducing water-cooled heat pumps using river water. Section 3 introduces specific examples of mitigation measures for urban heat island phenomenon using green shade. It also introduces ideas for the future development. First, we will introduce an experimental housing complex called NEXT 21 with an example of using green shade to mitigate the effects of urban heat. Namba Parks is an office and shopping complex that consists of low-rise commercial buildings and high-rise office buildings. As ideas for future development, we will introduce ideas that incorporate home gardens and small farms using rooftops and vacant rooms in the center of Osaka and in the Semba area. In Section 4, examples of mitigation measures for the heat island phenomenon using the wind blowing along the river and ideas for future development are introduced. In the city center of Osaka, there are large and small rivers flowing along Osaka Bay. First, we will introduce wind and temperature data based on observations along these rivers. For future development, we will introduce an idea to mitigate the heater island phenomenon using the wind blowing along the Dotonbori River flowing from east to west in the center of Osaka.