Validity of green cover ratio as an indicator of the environment for the mitigation against urban heat island problem

In this study, the cooling effect of urban greenery was analyzed in order to discuss the validity of green cover ratio as an indicator of the environment when the mitigation against urban heat island problem is concerned. Information regarding building form and materials was collected using aerial photographs and field investigations in substantial urban areas. 3D-CAD models were then developed, and the all surface temperature distributions were calculated for the present conditions, and for a condition without any greenery. The difference between two conditions was analyzed referring to the green cover ratio. The result indicated that in the high density urbanized area like Minato, Tokyo, urban greenery didn't necessarily work to improve the thermal condition. Through the study, the needs for other process to evaluate the countermeasure to improve the environment in such areas were revealed.