Tracing invisible veins.

I am a hydrogeologist studying ocean–groundwater–surface water interactions.

About me

Updates

2026-03-20
Website renewed.
2026-03-12
New publication in Water Resources Research.
Tajima, S., Therrien, R., & Brunner, P. (2026). Climate change alters post-surge recovery of coastal aquifers. Water Resources Research, 62(3), e2025WR042142.
2025-11-29
New preprint of a review paper.
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.
2025-11-09
New publication 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.

About Me

I am a hydrogeologist studying ocean–groundwater–surface water interactions.

Water is an indispensable resource sustaining human life, livelihoods, and ecosystems. Its accurate assessment and a thorough understanding of the hydrological cycle are therefore among the most pressing challenges in sustainable resource management. Groundwater, despite being an “invisible” resource, accounts for the vast majority of accessible freshwater and plays a unique role in the global water cycle due to its relatively slow movement. In coastal zones, where terrestrial and marine environments converge, groundwater acts as a primary pathway—a “vein”—connecting the two, making its characterization essential for capturing the full picture of the hydrological cycle.

My research focuses on the interactions among the ocean, groundwater, and surface water in coastal zones, aiming to elucidate the physical mechanisms governing groundwater flow and solute transport. Using numerical modelling and stochastic approaches, I investigate how coastal groundwater systems respond to environmental perturbations, such as storm surges and climate change, and assess their broader implications for coastal ecosystems, water resources, and human communities.

Professional Experience

2025 –
Postdoctoral Fellow | University of Neuchâtel / University of Bern
2023 – 2025
Research Fellow | Japan Society for the Promotion of Science (JSPS)
2022 – 2023
Visiting Researcher | Spanish National Research Council (CSIC)
2020 – 2023
WINGS-PES Research Assistant | The University of Tokyo

Education

2025
PhD in Environmental Sciences | The University of Tokyo
2022
MSc in Environmental Sciences | The University of Tokyo
2020
Bachelor of Agriculture | The University of Tokyo

Research Topics

Storm-surge Impacts on Coastal Aquifers

Public Policy for Offshore Wind Development

Tajima et al. (2021) JSOP Yamaguchi et al. (2024) JSOP Yamaguchi et al. (2024) EIS Tajima et al. (2024) Marine Policy