Regional Water Environment Systems

Sustainable Water Resources Development and Management

Water is one of the most precious and unevenly distributed natural resources in the world. Human beings have adapted with changing natural hydrological systems and increasing water demand. Learning past experiences, we develop the concept of integrated water resources management for promoting sustainable development under socioeconomic and climate change conditions.

Academic Staff


Kenji TANAKAProfessor (Disaster Prevention Research Institute)

Research Topics

A new land surface scheme SiBUC, which can treat urban area, water body, vegetation, agricultural cropland, is developed, and this LSS is coupled into various kinds of numerical weather prediction model to clarify the mechanism of energy/water cycle at global, continental, and regional scale, and to improve the ability for its prediction.


Room S-426D, Disaster Prevention Research Institute, Uji Campus
TEL: +81-774-38-4246
FAX: +81-774-38-4246

Kazuaki YOROZU

yoroAssociate Professor (Disaster Prevention Research Institute)

Research Topics

Atmosphere - land surface interaction impact on hydrologic cycle; Land surface modeling considering human activities; and Applications of land surface model for global water resources analysis.



Yoshiya TOUGE

Associate Professor (Disaster Prevention Research Institute)

Research Topics


Room S-424D, Disaster Prevention Research Institute, Uji Campus
TEL: +81-774-38-4246


Research Topics

Integrated Water Resources Manage-ment model

The "integrated water resources management model" consists of a distributed hydrological model, land surface process (LSP) model, groundwater (GW) model, water quality (WQ) model, sediment transport model, food chain model, crop growth model, reservoir operation model, socioeconomic model, etc. is being developed. This model is an integrated model which describes not only natural hydrological systems but also artificial systems such as those capable of regulating floods and releases from reservoirs in order to satisfy the demand from each sector. This model is expected to be applied to various kind of topics, such as diagnosis of the reliability of the current water resources system, decision support for water resources planning, evaluation of risks related to floods, droughts and ecosystems under future climate change, and proposal of risk reduction and adaptation measures to the anticipated impact from climate change.


Figure-1  Structure of integrated water resources management model

Hazard Monitoring and Risk Assessment

Disasters have been triggers to decide countermeasures, however, proactive approaches in the non-stationary condition are necessary. In order to monitor the water-related hazard, we are developing monitoring schemes. Further, we are assessing future water-related risk due to climate change in order to make appropriate political decisions.


Figure-2 shows Mann-Kendall Indices of Annual Precipitation and Annual Maximum Daily Precipitation of each Meteorological Station in Japan. Annual Precipitations at most stations are in slightly decreasing but not significant. 13 stations are significantly decreasing and 4 stations increasing. For Annual Maximum Daily Precipitation, most stations have no significant trend. 8 stations are significantly increasing and two stations decreasing.


Figure-3 shows Probability plots of Peaks over Threshold(POT) of daily precipitation (threshold:100mm) against three periods, such as 1940-1964, 1965-1989 and 1990-2014. It can be seen fitting curves are moving right ward, that is, return level has become bigger. In other words, heavy rainfall with a magnitude has become more frequent recently.


Climate Change Impacts on Water Resources

Global warming may change the amount and patterns of precipitation, leading to change the phase of the winter season’s precipitation from snowfall to rainfall. This could cause a great change in the pattern of water flowing into rivers. We aim to assess the changes in the available water resources of the major rivers in Japan and the world considering the changes in the water requirement under future socioeconomic and climate scenarios.

Groundwater Management

Depletion of groundwater resources has become obvious in many parts of the world. Land surface model has been upgraded to monitor the groundwater storage change through recharge and groundwater withdrawal processes. Recharge rate is governed by climate, topography, geology, and land use conditions. We are investigating the strategy for land and groundwater utilization toward sustainable water resources management.



Figure-4  Global distribution of agricultural water requirement


Figure-5  Global distribution of future change in agricultural water requirement (future/present)