EGU General Assembly 2022
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

The timing of unprecedented hydrological drought under climate change

Yusuke Satoh1,2, Kei Yoshimura3, Yadu Pokhrel4, Hyungjun Kim3,5,6, Hideo Shiogama1, Tokuta Yokohata1, Naota Hanasaki1, Yoshihide Wada2,7, Peter Burek2, Edward Byers2, Hannes Müller Schmied8,9, Dieter Garten10,11, Sebastian Ostberg10, Simon Gosling12, Julien Boulange1, and Taikan Oki13
Yusuke Satoh et al.
  • 1National Institute for Environmental Studies, Center for Global Environmental Research, Tsukuba, Japan (
  • 2International Institute for Applied Systems Analysis, Laxenburg, Austria
  • 3Institute of Industrial Science, The University of Tokyo, Tokyo, Japan
  • 4Department of Civil and Environmental Engineering, Michigan State University, Michigan, USA
  • 5Moon Soul Graduate School of Future Strategy, Korea Advanced Institute of Science and Technology, Daejeon, Korea
  • 6Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Korea
  • 7Department of Physical Geography, Utrecht University, Utrecht, Netherlands
  • 8Institute of Physical Geography, Goethe-University Frankfurt, Frankfurt am Main, Germany
  • 9Senckenberg Leibniz Biodiversity and Climate Research Centre Frankfurt, Frankfurt am Main, Germany
  • 10Potsdam Institute for Climate Impact Research, Member of the Leibniz Association, Potsdam, Germany
  • 11Geography Department, Humboldt-Universität zu Berlin, Berlin, Germany
  • 12School of Geography, University of Nottingham, Nottingham, UK
  • 13Graduate School of Engineering, The University of Tokyo, Tokyo, Japan

Droughts that exceed the magnitudes of historical variation ranges could occur increasingly frequently under future climate conditions. However, the time of the emergence of unprecedented drought conditions under climate change has rarely been examined. Here, using multimodel hydrological simulations, we investigate the changes in the frequency of hydrological drought (defined as abnormally low river discharge) under high and low greenhouse gas concentration scenarios and existing water resource management measures and estimate the timing of the first emergence of unprecedented regional drought conditions. When investigating 59 subcontinental-scale regions, the times are detected for 11 and 18 regions under low and high greenhouse gas concentration scenarios, respectively. Three regions (Southwestern South America, Mediterranean Europe, and Northern Africa) exhibit particularly robust and early timings under the high-emission scenario. These three regions are likely to confront unprecedented conditions within the next 30 years with a high likelihood regardless of the emission scenarios. Additionally, the results obtained herein demonstrate the benefits of the lower-emission pathway in reducing the likelihood of emergence. The Paris Agreement goals are shown to be effective in reducing the likelihood to the unlikely level in most regions. However, appropriate and prior adaptation measures are considered indispensable when facing unprecedented drought conditions. The results of this study underscore the importance of improving drought preparedness within the considered time horizons.

How to cite: Satoh, Y., Yoshimura, K., Pokhrel, Y., Kim, H., Shiogama, H., Yokohata, T., Hanasaki, N., Wada, Y., Burek, P., Byers, E., Müller Schmied, H., Garten, D., Ostberg, S., Gosling, S., Boulange, J., and Oki, T.: The timing of unprecedented hydrological drought under climate change, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-6687,, 2022.