• Taikan Oki

    Professor, Graduate School of Engineering
    Special Advisor to President, the University of Tokyo
    Senior Vice-Rector, United Nations University, Japan
    Assistant Secretary-General, United Nations

His previous academic positions include Associate Professor with the Institute of Industrial Science, The University of Tokyo and Associate Professor with the Research Institute for Humanity and Nature. He continues to serve concurrently as a Special Advisor to the President and a Professor (Integrated Research System for Sustainability Science; IR3S) of The University of Tokyo.

His areas of expertise are global hydrology and the sustainability of world water resources including the virtual water trade and water footprint. He was one of the coordinating lead authors for the chapter “Freshwater Resources” of the IPCC WGII AR5. He got many awards such as the Biwako Prize for Ecology in 2011, and the Japan Academy Medal in 2008. He is the first Japanese AGU Fellow in its Hydrology Section (2014).

Research Fields
  • Global Hydrologic Cycles and World Water Resources
  • Impacts of Climate Change and Adaptation
  • Millennium Sustainability
Brief CV
  • 1989
    M.Eng., Dept. of Civil Engineering, University of Tokyo
  • 1993
    Ph.D., University of Tokyo
  • 1989.9
    Research Associate, Institute of Industrial Science, The University of Tokyo
  • 1995.5
    Assistant Professor, Institute of Industrial Science, The University of Tokyo
  • 1997.10
    Associate Professor, Institute of Industrial Science, The University of Tokyo
  • 2002.4
    Associate Professor, Research Institute for Humanity and Nature
  • 2003.12
    Associate Professor, Institute of Industrial Science, The University of Tokyo
  • 2006.11
    Professor, Institute of Industrial Science, The University of Tokyo
  • 2016.6 - 2017.3
    Special Advisor to the President, The University of Tokyo
  • 2016.10 - 2018.9
    Senior Vice-Rector, United Nations University. Assistant Secretary-General, United Nations. (cross-appointment)
  • 2017.4 -
    Special Advisor to President, the University of Tokyo
  • 2018.4 -
    Professor, Institute of Industrial Science, The University of Tokyo
Research Projects
  • New frontiers in global hydrology
  • Development of an Integrated Assessment Model incorporating Global-scale Climate Change Mitigation and Adaptation
  • Advancing co-Design of integrated strategies with AdaPtation to climate change in Thailand(ADAP-T)
  • Development of Groundwater Utilization System under Emergent Conditions such as Natural Disasters including Critical Droughts
Major Publications

『水の未来 ─ グローバルリスクと日本 』(岩波新書)
『水危機 ほんとうの話』(新潮選書)


Yokohata, T., K. Tanaka, K. Nishina, K. Takahashi, S. Emori, M. Kiguchi, Y. Iseri, Y. Honda, M. Okada, Y. Masaki, A. Yamamoto, M. Shigemitsu, M. Yoshimori, T. Sueyoshi, K. Iwase, N. Hanasaki, A. Ito, G. Sakurai, T. Iizumi, M. Nishimori, W. H. Lim, C. Miyazaki, A. Okamoto, S. Kanae, and T. Oki, 2019: Visualizing the interconnections among climate risks. Earth’s Future, 7. https://doi.org/10.1029/2018EF000945

Shinichiro Nakamura and Taikan Oki, 2018: Paradigm Shifts on Flood Risk Management in Japan: Detecting Triggers of Design Flood Revisions in the Modern Era, Water Resour. Res., 54. doi: 10.1029/2017WR022509

Jamal Zaherpour, and co-authors including Taikan Oki, 2018: Worldwide evaluation of mean and extreme runoff from six global-scale hydrological models that account for human impacts, Environ. Res. Lett. 13, 065015.

Anne-Marie Boulay, and co-authors including Taikan Oki, 2018: The WULCA consensus characterization model for water scarcity footprints: assessing impacts of water consumption based on available water remaining (AWARE), Int J Life Cycle Assess, 23(2), 368-378.

Ferguson, C. R., Pan, M., & Oki, T., 2018: The effect of global warming on future water availability: CMIP5 synthesis, Water Resources Research, 54, 7791-7819. https://doi.org/10.1029/2018WR022792

Yano, Shinjiro, Toshio Okazumi, Yoshihisa Iwasaki, Masahiro Yamaguchi, Kenichi Nakamura, Takuhiro Kanayama, Daikichi Ogawada, Akiko Matsumura, Martin Gomez-Garcia, and Taikan Oki, 2018: How Inter-Basin Transfer ofWater Alters Basin Water Stress Used for Water Footprint Characterization, Environments, 5(9), 105. https://doi.org/10.3390/environments5090105

Yoshihiko Iseri, Sayaka Yoshikawa, Masashi Kiguchi, Ryunosuke Tawatari, Shinjiro Kanae, Taikan Oki, 2018: Towards the incorporation of tipping elements in global climate risk management: probability and potential impacts of passing a threshold, Sustainability Science, 13(2), March 2018, 315-328.

Park, K.J., K. Yoshimura, H. Kim, and T. Oki, 2017: Chronological development of terrestrial mean precipitation, Bull. Amer. Meteorol. Soc., 98(11), 2411-2427.

Mateo, C.M.R., D. Yamazaki, H. Kim, A. Champathong, J. Vaze, and T. Oki, 2017: Impacts of spatial resolution and representation of flow connectivity on large-scale simulation of floods, Hydrol. Earth Syst. Sci., 21, 5143-5163.

Wada, Yoshihide, and co-authors including Taikan Oki, 2017: Human-water interface in hydrological modeling: Current status and future directions, Hydrol. Earth Syst. Sci., 21, 4169-4193.

Maeda, E.E., X. Ma, F. Wagner, H. Kim, T. Oki, D. Eamus, and A. Huete, 2017: Evapotranspiration seasonality across the Amazon basin, Earth System Dynamics, 8(2), 439-454.

Veldkamp, T.I.E. , and co-authors including T. Oki, 2017: Water scarcity hotspots travel downstream due to human interventions in the 20th and 21st century, Nature Communications, 8, 15697.

Oki, T., S. Yano, and N. Hanasaki, 2017: Economic aspects of virtual water trade, Environ. Res. Lett., 12(4), 044002.

Utsumi, N., H. Kim, S. Kanae, and T. Oki, 2017: Relative contributions of weather systems to mean and extreme global precipitation, J. Geophys. Res.-Atmospheres, 122(1), 152-167.

Fukuda, S., M. Murakami, K. Noda, and T. Oki, 2016: How achieving the Millennium Development Goals increases subjective well-being in developing nations, Sustainability, 8, 189.

Utsumi, N., H. Kim, S. Kanae, and T. Oki, 2016: Which weather systems are projected to cause future changes in mean and extreme precipitation in CMIP5 simulations?, J. Geophys. Res.-Atmospheres, 121(18), 10522-10537.

Schmied, H.M., L. Adam, S. Eisner, G. Fink, M. Florke, H. Kim, T. Oki, F.T. Portmann, R. Reinecke, C. Riedel, Q. Song, J. Zhang, and P. Döll, 2016: Variations of global and continental water balance components as impacted by climate forcing uncertainty and human water use, Hydrol. Earth Syst. Sci., 20, 2877-2898.

Maeda, E.E., H. Kim, L.E.O.C. Aragao, J.S. Famiglietti, and T. Oki, 2015: Disruption of hydroecological equilibrium in southwest Amazon mediated by drought, Geophys. Res. Lett., 42.

Kim, H., and T. Oki, 2015: River Discharge, in State of the Climate in 2014, Special Supplement to the Bull. Amer. Meteor. Soc., 96(7), 526-527.

Döll, P., B. Jimenez-Cisneros, T. Oki, N.W. Arnell, G. Benito, J.G. Cogley, T. Jiang, Z.W. Kundzewicz, S. Mwakalila and A. Nishijima, 2015: Integrating risks of climate change into water management, Hydrol. Sci. J., 60(1), 4-13.

Utsumi, N., H. Kim, S. Seto, S. Kanae, and T. Oki, 2014: Climatological characteristics of fronts in the western North Pacific based on surface weather charts, J. Geophys. Res.-Atmospheres, 119(15), 9400-9418.

Pokhrel, Y., N. Hanasaki, P. J-F. Yeh, T. J. Yamada, S. Kanae, and T. Oki, 2012: Model estimates of sea-level change due to anthropogenic impacts on terrestrial water storage, Nature Geosci, 5, 389-392.

Utsumi, N., S. Seto, S. Kanae, E. Maeda, and T. Oki, 2011: Does higher surface air temperature intensify extreme precipitation?, Geophys. Res. Lett., 38, L16708.

Yamazaki, D., S. Kanae, H. Kim, and T. Oki, 2011: A physically based description of floodplain inundation dynamics in a global river routing model, Water Resour. Res., 47(4), W04501.

Yang, D., W. Shao, P. J. -F. Yeh, H. Yang, S. Kanae, and T. Oki, 2009: Impact of vegetation coverage on regional water balance in the nonhumid regions of China, Water Resour. Res., 45, W00A14.

Oki, T., and S. Kanae, Global Hydrological Cycles and World Water Resources, 2006: Science, Vol. 313. No. 5790, 1068-1072.

Koster, R.D., and co-authors including T. Oki, 2004: Regions of strong coupling between soil moisture and precipitation, Science, 305(5687), 1138-1140.

Oki, T., and Y. C. Sud, 1998: Design of Total Runoff Integrating Pathways (TRIP) A global river channel network, Earth Interactions, 2.

Oki, T., K. Musiake, H. Matsuyama, and K. Masuda, 1995: Global atmospheric water balance and runoff from large river basins, Hydrological Processes, 9, pp.655-678.

Honors and awards
  • 2014 AGU Fellow, American Geophysical Union
  • 2014 JICA President Award
  • 2014 Cultural Publication Award, Japan Society of Civil Engineering
  • 2013 Academic Publication Award, Japan Society of Hydrology and Water Resources
  • 2011 Biwako Prize for Ecology, The Ecological Society of Japan
  • 2009 JSHWR Paper Award, Japan Society of Hydrology and Water Resources
  • 2009 Award for Persons of Distinguished Services to the Promotion of Science and Technology related to Ocean
  • 2008 Nikkei Global Environmental Technology Awards
  • 2008 Science and Technology Prize, Ministry of Education, Culture, Sports, Science, & Technology
  • 2008 Japan Academy Medal, The Japan Academy
  • 2008 JSPS PRIZE, Japan Society for the Promotion of Science
  • 2005 Award in the field of Environment, JSCE
  • 2004 Incentive Award, Japan Water Award
  • 2003 IAHS Tison Award
  • 1998 Scientific Award from Japan Society of Hydrology and Water Resources