Satoshi Tajima

Satoshi Tajima, PhD

Hydrogeologist
E-mail: satoshi.tajima[at]unine.ch
Satoshi Tajima is Postdoctoral Fellow at the Centre for Hydrogeology and Geothermics, University of Neuchâtel, and at the Physics Institute, University of Bern. He earned his PhD from the University of Tokyo in 2025. As a hydrogeologist, he investigates the dynamics of complex physical processes in subsurface environments, such as solute transport, density-driven flow, and surface-subsurface hydrological interactions, primarily through numerical modelling and stochastic approaches.
田嶋 智 (たじま さとし) スイス・ヌーシャテル大学／ベルン大学 ポストドクトラル・フェロー
専門は地圏水文学。溶質輸送や密度依存流、地表水–地下水相互作用など、地下環境における複雑な物理的過程のダイナミクスの解明を目指し、数値解析および確率論的手法を用いて研究を行っている。博士 (環境学)。
Satoshi Tajima est postdoctorant au Centre d’hydrogéologie et de géothermie (CHYN) de l’Université de Neuchâtel ainsi qu’à l’Institut de physique de l’Université de Berne. Il a obtenu son doctorat à l’Université de Tokyo en 2025. Ses travaux portent sur la dynamique de processus physiques complexes dans les milieux souterrains, notamment le transport de solutés, les écoulements à densité variable et les interactions entre les eaux de surface et les eaux souterraines, principalement à l’aide de la modélisation numérique et d’approches stochastiques.

News

  • 2025-11-29: Released a preprint of a review paper on ESS Open Archive .
    (Tajima, S., Purtschert, R., Savard, M.–C., Rosier, M., Kotra, K. K., Therrien, R., Coulombe, C., Müller, C., Masse–Dufresne, J., Richard, F., Bertone, L., Barbecot, F., Lucas–Picher, P., Tigona, R., Corcho Albarado, J. A., & Brunner, P. (2025). Groundwater in the Pacific Islands under Climate Change. Preprint at ESS Open Archive.)
    This transdisciplinary review synthesizes hydrogeological background, climate change impacts, and adaptation strategies to support sustainable groundwater management in the Pacific Islands, outlining key considerations for designing and implementing effective, context-relevant adaptation measures.
  • 2025-11-09: Published a paper in Water Resources Research .
    (Tajima, S. & Dentz, M. (2025). Tides and heterogeneity drive trapping and chaotic mixing in coastal aquifers. Water Resources Research, 61(11), e2025WR040620.)
    In this study, we show that the interplay of heterogeneity, buoyancy, and tidal fluctuations in coastal aquifers generates chaotic and periodic flow orbits within the freshwater–saltwater transition zone. These orbits both trap solute particles and enhance mixing between freshwater- and seawater-derived solutes. The findings have broad implications, including long-term contamination risks in coastal aquifers, potential influences on marine ecosystems from altered submarine groundwater discharge characteristics, and the formation of hotspots for subsurface chemical and biological reactions.
  • 2025-09-11: Released a preprint on ESS Open Archive .
    (Tajima, S., Therrien, R., & Brunner, P. (2025). Climate change alters post-surge recovery of coastal aquifers. Preprint at ESS Open Archive.)
    This study reports on how climate-change-driven shifts in the intensity and frequency of storm surges influence the recovery of coastal aquifers after repeated surges and the associated vertical seawater intrusion.
  • 2025-06-14: Published a paper in Advances in Water Resources .
    (Tajima, S. & Dentz, M. (2025). Transient forcing in heterogeneous aquifers drives solute containment and chaotic mixing. Advances in Water Resources, 203, 105021.)
    In this study, we found that the combination of heterogeneity and transient forcing produces complex flow patterns, with stable regions that promote solute containment and chaotic regions that enhance mixing simultaneously. These results have important implications for assessing seawater intrusion in coastal aquifers and for designing effective strategies for groundwater remediation and geological storage.