Organization

Water is the most abundant substance on the earth, the principal constituent of all living things, and a major force constantly shaping the surface of the earth. It is also a key factor in air-conditioning the earth for human existence and in influencing the progress of civilization. Changes in the distribution, circulation, or temperature of the earth’s waters can have far-reaching effects; the ice ages, for instance, were a manifestation of such effects. Changes may be caused by human activities, in particular, since the latter half of the 20th century. People cultivate the soil, irrigate crops, fertilize the land, clear forests, pump groundwater, build dams, dump wastes into rivers and lakes, and do many other constructive or destructive things that affect the circulation and quality of water in nature. Besides, an expanding population and a rapidly growing economy especially in Asia and Africa are hindering sustainability on the globe.
Our studies and challenges have been focused on solving the world water issuers by understanding water circulation, along with the following subjects: (1) Impact assessment on the hydrological change under the changing climate and the land use change at a global and local scale; (2) Mechanism of slope failure and wood debris by torrential rains; (3) Socio-hydrology: trade-offs between urban flood resilience and urbanisation; (4) Numerical study on water pollution in the inundation areas; (5) Long-term heat, vapour and carbon dioxide fluxes observation for an impact assessment on the interaction between land and atmosphere. 
Furthermore, the following inter-/trans-disciplinary research has been focused on achieving local sustainability: (6) Understanding requirements for sustainability of community-based programs; (7) Value-based co-creation of technology and lifestyle for a society based on a virtuous materials cycle.

The current social infrastructures for disaster prevention are insufficient to cope with the increasing number of slope failure disasters with large wood discharges in recent years, not only in Japan but also in the world, considering the impact of climate change in the future. Therefore, an integrated model of slope failure disasters with large wood discharge was developed. I am working on the further advancement of the model, and am also engaged in research that contributes to the realisation of comprehensive watershed management, to design regional environments and rural infrastructure that are in harmony with the natural environment.
 

Socio-hydrology is a new research field that includes not only theoretical research on the interaction between the natural hydrological cycle and human society as a whole, but also practical intellectual activities to apply the knowledge of hydrology to solving social issues. It is expected to promote interdisciplinary socio-hydrology in Japan, ranging from the humanities and social sciences to geophysical aspects through the hydrological cycle. Therefore, I am working on socio-hydrology to clarify the trade-off between urbanisation and water-related disasters by utilising urban flood area records. 

 

Understanding vulnerability in agriculture is also important from the perspective of global food supply and demand. Therefore, I am working on agricultural vulnerability to drought and flood disasters in Japan, Asia and the rest of the world.
I am also conducting transdisciplinary research on the nature of the relationship between human society and the natural water cycle and environment, and the mechanisms of local environmental issues, while clarifying the actual conditions of local communities that are changing in the face of globalisation through fieldwork and geographic information systems.