Masaatsu Aichi / Assistant Professor / Division of Environmental Studies
Department of Environment Systems / / Numerical/analytical modeling for subsurface fluid flow and poromechanics

Career Summary
2010: Ph.D. from the University of Tokyo
2010: JST Researcher, Department of Urban Engineering, School pf Engineering, University of Tokyo
2010: Project Researcher, Department of Environment Studies, School of Frontier Sciences, University of Tokyo
2012: Project Assistant Professor, Research into Artifacts, Center for Engineering, University of Tokyo
2014: Assistant Professor, Department of Environment Studies, School of Frontier Sciences, University of Tokyo

Educational Activities
Graduate school: Artifactology
Research Activities

In our laboratory, we study ways of developing a sustainable energy system, especially through hydrogeological and thermo-poro-mechanical modeling of geothermal heat pumps, geothermal power plants, and the geological sequestration of carbon dioxide.
We currently focus on:

1) A nested modeling scheme to integrate a regional groundwater/heat flow model and a detailed thermoporomechanical model for areas of interest

It is important to estimate the environmental impact and the energy efficiency of subsurface developments. This requires us to study total processes ranging from the local groundwater flow system to the regional groundwater flow system. We are developing a nested modeling scheme that enables us to simulate both regional and local processes with less computational load. (1)

2) Evaluation of in situ physical properties from passive measurements

The values of the physical parameters of geomaterials obtained from laboratory experiments are often different those estimated from field observations. Quantitative evaluation of in situ physical properties is therefore of great importance. We are developing a data analysis method to estimate physical properties from the measurement of groundwater level fluctuations caused by natural loads such as barometric pressure, tide, etc. (2)

3) Thermoporomechanics for porous media saturated with multiphase fluid

Geological formations are deformed by changes in temperature or pore pressure in the subsurface. We are trying to extend the theory of thermoporomechanics to a multiphase fluid system so that we can calculate the displacement of land surface caused by multiphase fluid flow. (3)
We are also trying to design a management scheme by combining prediction by numerical simulator with monitoring data. Our particular focus is on the spatial distribution of land surface displacement, which gives us some information on the subsurface fluid flow.
1j Aichi M., "Coupled Groundwater Flow/ Deformation Modelling for Predicting Land Subsidence" in Groundwater Management in Asian Cities: Technology and Policy for Sustainability, Takizawa S (eds.), Springer-Verlag: Tokyo, pp. 105-124 (Chap. 5), 2008.
2j Aichi M., Shiokari S., and Tokunaga T., "A new analytical solution of water table response to tidal fluctuations and its application to estimate aquifer properties on Niijima Island, Japan", Journal of Groundwater Hydrology, 53(3), 249-265, 2011 (in Japanese).
3) Aichi M. and Tokunaga T., "Material coefficients of multiphase thermo-poro-elasticity for anisotropic micro-heterogeneous porous media", Int. J. Solid. Struct., 49, 3388-3396.

Other Activities
American Geophysocal Union (AGU)
European Geosciences Union (EGU)
Future Plan
Current approaches to energy supply and consumption face problems such as climate changes and dwindling resources. The development of key technologies for saving energy, switching to renewable energy resources, and appropriately disposing of wastes is required. Our goal is to perform research that will contribute to the development of these technologies, especially by taking advantages of the characteristics of subsurface formations.
Messages to Students
Our knowledge of the environment is still poor despite rapid progress in science and technology. It is growing increasingly important for us to think of how to deal with uncertainties and to cope with unexpected situations while recognizing the limitations of human knowledge. I hope to work with active students and contribute to the progress of environment studies.