In the heart of Jinan, China, a team led by Yaru Zhao from the College of Earth Science and Engineering at Shandong University of Science and Technology has unlocked a critical piece of the puzzle for sustainable resource management. Their study, published in *Meitan xuebao* (Journal of the China Coal Society), presents a groundbreaking three-dimensional model of the Jinan karst aquifer system, revealing how cold groundwater and geothermal resources can be co-exploited without depleting the region’s iconic springs.
The Jinan karst aquifer is no ordinary groundwater system—it’s a complex network of interconnected caves and fractures that feed the city’s famous springs, a lifeline for both ecology and tourism. But beneath the surface lies another resource: geothermal energy, which has long been tapped separately from the cold groundwater. Zhao and her team recognized the flaw in this approach. “Separate assessments have left us with an incomplete picture,” Zhao explains. “We needed to see the whole system at once.”
Using COMSOL Multiphysics, the researchers built a detailed digital twin of the aquifer, incorporating decades of borehole data, groundwater levels, and geothermal well performance. The model didn’t just simulate water flow—it accounted for heat transfer, allowing them to test how pumping cold water upstream might affect geothermal extraction downstream. The results were eye-opening.
Under current conditions, the team found that the aquifer’s five subsystems are hydraulically linked, maintaining a delicate balance between recharge and discharge. In the upper reaches, where springs originate, sustainable groundwater extraction could reach 473,500 cubic meters per day—without drying up the springs. Meanwhile, in the lower reaches, where geothermal energy is concentrated, a balanced production-reinjection strategy could yield 43,300 cubic meters of geothermal water daily. “This isn’t just about avoiding depletion,” Zhao notes. “It’s about ensuring that every drop pulled from the ground serves a purpose—whether for drinking, industry, or heating.”
The commercial implications are significant. For energy companies, this model offers a blueprint for tapping geothermal resources without triggering thermal breakthroughs or disrupting spring flows. For water utilities, it provides a pathway to meet demand while preserving ecosystems. And for policymakers, it delivers a quantitative framework to balance competing needs.
What makes this research particularly compelling is its scalability. The Jinan aquifer is just one example of a coupled groundwater-geothermal system. Zhao’s team has demonstrated that with the right data and modeling tools, other regions could adopt similar strategies. The key, she suggests, lies in integrated planning. “We can’t treat groundwater and geothermal in isolation anymore. The future of sustainable development depends on seeing them as parts of a single system.”
As cities worldwide seek to decarbonize heating and secure water supplies, the Jinan case study offers a template. It’s a reminder that the most sustainable solutions often lie in understanding the connections we can’t see—until we model them.