The Mitsui & Co. Environment Fund

Introduction to Grant Projects

Division of Civil and Environmental Engineering, Graduate School of Science and Engineering, Yamaguchi University Associate Professor Yoshihisa Akamatsu

Configuration of a land-sea interface environment toward mangrove forest/coral reef ecosystem preservation/restoration on Okinawa Island

Research grant

Project Description

Coastal mangrove forest/coral reef ecosystems along the main island of Okinawa have essentially been destroyed. Technologies for restoring coral reefs have been under development in recent years, but their application requires a suitable preparation of land-see interfaces. Also, as for mangrove forests and coral reefs together, here it is necessary to consider interrelations between the two. In our research, we identify areas suitable for mangrove/coral restoration and also how land/coast interfaces should be environmentally arranged to restore and preserve a healthy ecosystem at such locations. More specifically, we create a GIS* database to compile information pertaining to coral reefs, vegetation (mangrove swamps), land utilization, coastal development and river water quality; and, with that database, we identify areas amenable to restoration. We apply the WEPP (water erosion prediction project) model to sediment (sand, mud) and nutrient loads; and, in addition, we utilize a 3-D flow model to reproduce the behavior of same. By this, we elucidate the degree to which coral habitats can be improved by reducing nutrient loading. We also conduct a quantitative assessment to arrive at the realistic plan for mangrove swamp /coral reef ecosystem.
*GIS (geographic information system): A geographic information system is a system (technology) for storing, processing, and otherwise comprehensively handling data relating to positions on the Earth's surface. It facilitates data analysis and interpretation.

Preservation of surface soil and forestsPreservation of biodiversity and ecosystem
Grant year
FY2007 Research Grants
Grant term
3 years
April 2008 - March 2011
Grant amount
8,130,000 yen
Activity region
Okinawa Prefecture
Taking observations along an Okinawan river

Overview of the Organization

Associate Professor Yoshihisa Akamatsu
Associate Professor Yoshihisa Akamatsu
Specialist fields
River engineering, applied ecological engineering, Earth environmental engineering
Affiliated academic societies
Japan Society of Civil Engineers; Ecology and Civil Engineering Society; Ecological Society of Japan; American Geophysical Union
In 2003 obtained a Ph.D. (engineering) from the Graduate School of Engineering from the Tokyo Institute of Technology. In 2003 became a Research Fellowship for Young Scientists at the Japan Society for the Promotion of Science. In 2006 was appointed Associate Professor at the Faculty of Engineering, University of the Ryukyus, Department of Civil Engineering and Architecture. In 2007 took the position of Visiting Associate Professor at the Graduate School of Engineering, Tokyo Institute of Technology
WEB site
Collaborating researchers
Eizo NAKAZA, Professor, Department of Civil Engineering and Architecture, Faculty of Engineering, University of the Ryukyus; Daisuke KAMIYA, Faculty of Engineering, University of the Ryukyus
Research record
  • (1) Yoshihisa AKAMATSU, Tadaharu ISHIKAWA, Syunsuke IKEDA. "Numerical simulation on habitat of coral reef in a bay." Japan Society of Civil Engineers, pp. 1483-1488, 2006.
  • (2) Syunsuke IKEDA, Yuji TODA and Yoshihisa AKAMATSU: Flow, Sediment, and Nutrient Transport in a Riparian Mangrove, Riparian Vegetation and Fluvial Geomorphology(Water Science and Application 8), American Geophysical Union, pp.171-185, 2004.
  • (3) Yoshihisa AKAMATSU, Syunsuke IKEDA. "Numerical simulation of material cycling in a mangrove area." Japan Society of Civil Engineers, No.768/II-68, pp.193-208, 2004.
  • (4) Yoshihisa AKAMATSU, Syunsuke IKEDA, Youhei NAKASHIMA, Yuji TODA. "Particle mass transport from mangrove swamps upon flooding", Proceedings of Japan Society of Civil Engineers, No.768/II-68, pp.179-191, 2004.
  • (5) Youhei NAKASHIMA, Syunsuke IKEDA, Yoshihisa AKAMATSU, Yasuaki MIYAMOTO, Satoshi YAMAGUCHI, Yuji TODA. "Field observation on the effluent of sediment and nutrient in Nagura Basin, Ishigaki Island." Proceedings of Japan Society of Civil Engineers, No.747/II-65, pp.173-185, 2003.
  • (6) Yoshihisa AKAMATSU, Syunsuke IKEDA, Youhei NAKASHIMA, Yuji TODA. "Tidal transport of organic materials and nutrients in a mangrove area at neap tide. Groundwater flow." Proceedings of Japan Society of Civil Engineers, No. 712/II-60, pp. 175-186, 2002.
  • (7) Yoshihisa AKAMATSU, Syunsuke IKEDA, Youhei NAKASHIMA, Yuji TODA. "Study on Tidal Transport of Organic Materials and Nutrients in a Mangrove Area by Field Observation. Spring tide." Proceedings of Japan Society of Civil Engineers, No. 698/II-58, pp. 69-80, 2002.