抄録
In Miyakojima, Okinawa prefecture, all of the water resources necessary for life, agriculture and industry depend on groundwater. However, because of the entire island of Miyakojima is formed by Ryukyu limestone, it is hard to collect groundwater though there is much rainfall. In the past, it was experienced “waterless agriculture” during major drought. For this reason, in Miyakojima, the large scale underground dam was constructed at first for the purpose of securing agricultural water. As the result, it has provided a stable supply of agricultural water by the underground dam. In recent years, Miyakojima has been visited by many tourists due to the crosslinking of the Irabu Bridge in 2015 and the opening of Shimojishima Airport in 2019. In addition, the number of people involved in construction of tourist facilities and residences is
increasing. Therefore, groundwater consumption will also increase. In the future, stable water stored in underground dams should be supplied for drinking. One such technology is the groundwater membrane filtration system. And also, comprehensive management of water stored in underground dams and natural groundwater should be considered. As the method, this paper proposes PFI (Private Finance Initiative) for the overall groundwater management in Miyakojima.
