The Mitsui & Co. Environment Fund

Introduction to Grant Projects

Makoto TANI, Professor, Graduate School of Agriculture, Kyoto University

Research on strategies for including the water functions of the forest into catchment management plans

Research grant

Project Description

As forest resources deplete on a global scale, we could well be witnessing a change in forest utilization scenarios. Conventional research on water circulation within the forest has focused on knowledge accumulation through observation. In this research, in contrast, we seek to apply such knowledge to the formulation of strategies for catchment management planning. First, we utilize observations from small catchment areas to develop a predictive model for heat fluxes, outflows, and water quality. Then, through sensitivity analysis with that model, we predict the influence of changes in catchment parameters on the water environment, estimating, for example, tree growth, shifts in tree species, and changes in soil composition. We next obtain catchment parameter distributions based on landscape evolution simulations and vegetation surveys, then studying seemingly heterogeneous effects on catchment water circulation. Based on this, we assess the flow regulatory function of catchment areas, primarily forests. We anticipate that such assessments will be of use in catchment management planning, particularly in terms of promoting local participation in same, by facilitating easy-to-understand explanations of water circulation in catchments (as, for example, when explaining to local residents how some project would have some effects similar to a dam and other effects dissimilar to a dam).

Preservation of surface soil and forests
Grant year
FY2008 Research Grants
Grant term
3 years
April 2009 - March 2012
Grant amount
34,510,000 yen
Activity region
Kyoto, Shiga and Okayama Prefectures, Japan; and Malaysia
Tower for measuring water vapor and carbon dioxide above a forest (R); weir for measuring water flux/quality from a forest catchment (L)

Overview of the Organization

Makoto Tani, Professor, Graduate School of Agriculture
Makoto Tani, Professor, Graduate School of Agriculture
Specialty fields
Forest hydrology; forest water flow and its effect on heat dissipation
Affiliated academic societies
Japan Society of Hydrology and Water Resources; the Japan Forest Society; Japan Society of Erosion Control Engineering; the Society of Agricultural Meteorology of Japan; American Geophysical Union
Acquired a Ph.D. in 1980 from the Graduate School, Division of Agriculture, Kyoto University. In 1981 took the position of Scientist at the Forestry Research Institute. In 1988 became an employee of the Forestry and Forest Products Research Institute and in 1999 was made a Professor at the Graduate School of Agriculture, Kyoto University. In 2006 was appointed Vice chairman of the Japan Society of Hydrology and Water Resources.
Collaborating researchers
Yoshiko KOSUGI, Assistant Professor, Kyoto University Graduate School of Agriculture; Kenichiro KOSUGI, Associate Professor, same; Professor Shigeto KAWASHIMA, same; Associate Professor Kimihito NAKAMURA, same; Professor Eiichi NAKAKITA, Disaster Prevention Research Institute (DPRI), Kyoto University; Assistant Professor Yasuyuki KAGOTANI, Department of Ecosystem Studies, the University of Shiga Prefecture; Assistant Professor Masahiro NAGAI, University of Human Environments; Nagahiro KOJIMA, Researcher, Shiga Forest Research Center
Research record
  • (1) Tani, M.: An approach to annual water balance for small mountainous catchments with wide spatial distributions of rainfall and snow water equivalent, Journal of Hydrology 183, 205-225, 1996.
  • (2) Tani, M.: Runoff generation processes estimated from hydrological observations on a steep forested hillslope with a thin soil layer. Journal of Hydrology 200, 84-109, 1997.
  • (3) Tani, M.: A concept for runoff processes on a steep forested hillslope, Sassa, K. (ed.): Environmental Forest Science, 455-462, Kluwer, 1998.
  • (4) Tani, M. et al,: Characteristics of energy exchange and surface conductance of a tropical rain forest in Peninsular Malaysia. In Okuda, et al.,(eds.) : Pasoh – Ecology of a Lowland Rain Forest in Southeast Asia, 73-88, Springer, 2003
  • (5) Tani, M.: Analysis of runoff–storage relationships to evaluate the runoff-buffering potential of a sloping permeable domain. Journal of Hydrology 360, 132-146, 2008.
  • (6) Tani, M.: Role of the forest in water circulation, Ohta Seiichi, editor: Shinrin no Saihakken, 133-183, Kyoto University Press, 2007.