Exploring the Relationship Between Groundwater and Forests: The Rusutsu Terrain Traversed by Professor Kuraji and Dr. Takashima
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“Groundwater and surface water may look alike, yet they behave in completely different ways.”
That memorable remark was shared during the survey.
In May 2025, experts carried out geological and forestry fieldwork in Rusutsu, Hokkaido, to explore how water and forests interact.
Water-resources segment
- Candidate sites were chosen for measuring well-water levels, and preparations began to install IoT sensors with built-in communications.
- Locations for sensors that will track rainfall and the influence of snow were also discussed.
- This painstaking groundwork is the first step toward answering the question, “Where does this water come from?”
Forestry segment
- The team assessed whether overcrowded stands could be thinned.
- Tree density and the state of the understory are key to boosting the forest’s ability to let water infiltrate the soil—a process known as recharge.
Green-infrastructure idea
- Particular attention was paid to “leaky dams,” natural weirs made from fallen trees that slow streamflow and allow water to seep gradually into the ground—an approach that harnesses nature without harming it.
Professor Kuraji’s words lingered:
“Instead of trying to control water, think like the water itself.”
Rusutsu’s new resort development is moving forward by listening to the voices of geology and forests, and it is grounded in this diligent fieldwork and the insights of specialists.
