Freshwater Resources in Arid Lands (UNU, 1997, 94 pages): 5: The development of groundwater resources on the Miyakojima Islands: Introduction

Freshwater Resources in Arid Lands (UNU, 1997, 94 pages)

5: The development of groundwater resources on the Miyakojima Islands

		(introductory text...)
		Introduction
		Outline of the Miyakojima Islands
		Geology and the hydrological cycle
		Outline of the irrigation project on Miyakojima
		The construction and concept of the underground dam
		The Construction of the Cut-off Walls
		The construction of the intake facilities
		The storage situation of the Sunagawa underground dam
		Conclusion
		Bibliography

Introduction

An estimation of potential and available groundwater resources is very difficult because of their invisibility. In the case of the construction of underground dams that store the groundwater How, we need to consider many technical issues. Since 1990, on the Miyakojima Islands, the Japan Agricultural Land Development Agency (JALDA) has been implementing a project to construct two underground dams that will be the largest in the world. One of the two was completed in November 1993 and the other is now under construction. This report presents the concept of the underground dams on the Miyakojima Islands, the construction methods, and related technical issues.