On 12 December 2025, a live demonstration linked to the hydrogeological exhibition “Visible and Invisible Waters Tabletop Model & Nature-Based Targeted Managed Aquifer Recharge Model” took place at the Headquarters of the Hungarian Academy of Sciences (HAS), attracting strong public and professional interest. The programme was delivered as part of the MTA200 Earth sciences event series.
The event was realised through the joint contribution of the József and Erzsébet Tóth Endowed Hydrogeology Chair, Faculty of Science, Eötvös Loránd University (ELTE) (Judit Mádl-Szőnyi, Márk Szijártó, Ildikó Erhardt, Imola Koszta, Hanna Lukács), ELTE’s Kármán Laboratory (Miklós Vincze), and the Dunakanyar Cultural Landscape and Environmental Protection Association (DUNAKÉKE) (Mónika Korcsák, Gábor Korcsák).
Throughout the day, the mezzanine exhibition space welcomed school groups, adult visitors, and experts from the water and agricultural sectors. Two main thematic stations guided participants through the “visible” and “invisible” parts of the water cycle and their relevance for sustainable water management:
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the “Visible and Invisible Waters” tabletop model, and
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the NaBa-MAR® board model presenting nature-based, targeted managed aquifer recharge.
Visible and Invisible Waters – Understanding the Effects of Human Interventions
The tabletop model follows water from clouds and precipitation through the landscape to a river valley, illustrating how surface water and groundwater are connected. Visitors could observe how water infiltrates through the soil to the groundwater table, and then—largely invisible to us—moves within groundwater flow systems from higher-elevation areas towards lower-lying valleys.
A central aim of the demonstration was to make the role and consequences of human interventions visible—especially in relation to the “hidden” groundwater component of the water cycle. The model clearly distinguished between:
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sources of pollution (e.g., mining activities, oil barrels),
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water abstraction, which can contribute to declining groundwater levels, and
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positive examples—solutions that help retain water locally, enhance infiltration, and improve the landscape water balance.
Among the nature-friendly measures presented were:
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mulching, which protects soils from drying and supports infiltration,
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an infiltration pond, enabling surface water to be retained locally and gradually routed underground, and
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a brushwood hedge, which functions as a living, biodiverse green strip—providing habitat while also supporting water retention and soil protection.
NaBa-MAR® Physical Model – Nature-Based Managed Aquifer Recharge
The second station focused on the NaBa-MAR® board model, demonstrating the principles of Nature-Based Managed Aquifer Recharge—an ELTE innovation protected under EU trademark. With the help of the model, visitors could follow how water available at the surface—such as precipitation or temporary surplus flows in watercourses—can be guided into aquifer layers in a controlled way that still builds on natural processes.
During the live demonstration, we explained how the model is built, how groundwater flow develops within it, and what happens when additional water is infiltrated into the system. We also illustrated how rapid drainage through channels, when not properly coordinated, can jeopardise the success of recharge efforts by removing water from the landscape too quickly.
Step by step, the board model showed how the geological subsurface can function as a “natural reservoir”: infiltrating water not only increases groundwater storage but also helps stabilise the local water balance and supports adaptation to climate change. The explanations highlighted how such systems can help mitigate drought impacts, reduce risks linked to hydrological extremes, and fit into broader toolkits for sustainable water management and land use.
Experience-Based Learning for All Ages
On 12 December, participants—regardless of age or background—found questions to explore and answers to take home. Younger visitors were often most impressed by the “journey of a water drop” and the tabletop’s visual elements, while professionals engaged in discussions on deeper hydrogeological mechanisms and practical applicability.
Feedback emphasised that making “invisible” processes tangible had a particularly strong effect: many participants noted that the demonstration helped them understand how closely surface water and groundwater are interconnected, and why the responsible, long-term management of water resources is a key priority for sustainability.
