Abstract
We carried out an experiment on the roof of a multistory car park in Motobu in Okinawa to test the effectiveness of greening car park roofs. We planted greenery in experimental lightweight plots 15 cm deep on the car park roof, and then we checked how useful the greening was. There were 4 varieties of 3 types of experimental plots - block-type; protected-type and a type made of mixed material. During the one and a half years of the duration of the experiment, ordinary vehicles parked on the test plots for an average of 4.1 days per week. The results showed that the block-type and mixed material type retained the conditions to maintain healthy growth and a high rate of green cover, although this excluded continuous periods of 16 days when there was no rainfall. We noticed pressure marks from tires that appeared during this experiment when a parking bay was used during the day, 4 days a week,so by adding supplementary material used in the Okinawa region to the normal roof top greening, we ascertained that greening for car parks could be done in artificial ground.
