Contrasting Hydrodynamic Behavior and Climate Sensitivity of Two Karst Springs in the Aggtelek Karst (NE Hungary): Evidence for System-Dependent Climate Responses

Karst spring discharge is highly sensitive to climatic variability, but responses may differ markedly even within the same karst region. We compared long-term discharge dynamics and potential future changes of the Nagy-Tohonya and Jósva springs in the Aggtelek Karst (NE Hungary) using statistical analysis, flow duration curves, recession coefficients, periodicity analysis, and hydrological modelling driven by climate projections. The two springs exhibit contrasting hydrological behavior: Nagy-Tohonya shows high discharge variability and rapid responses to recharge, whereas Jósva exhibits a more buffered discharge regime with lower relative variability and more sustained low flows. Future simulations project decreasing mean discharge for both springs during 2022–2059, followed by contrasting late-century responses. Nagy-Tohonya remains highly variable but shows comparatively limited changes in its overall discharge distribution, whereas Jósva exhibits a widening discharge range, with increasing high flows and declining low flows. Model evaluation indicates that simulated discharge variability is generally damped, requiring caution when interpreting projected extremes. These results demonstrate that climatechange impacts cannot be generalized across geographically close karst systems and emphasize the need for system-specific assessment, climate adaptation, and water management strategies addressing both future water availability and hydrological extremes.