Revealing spring discharge variability through long-term hydrogeological monitoring: insights from case studies in the Aosta Valley

Springs are key discharge points in groundwater systems and provide valuable insights into aquifer dynamics, particularly in Alpine regions, where they often represent the primary expression of subsurface flow. In the Aosta Valley (northwestern Italian Alps), a long-term monitoring network has been operating since 2010 to record water levels, temperatures, and electrical conductivity at representative springs across different geological and climatic settings. By applying site-specific weir equations to continuous water-level data, discharge values were derived for multiple sites over a 14-year period (2010–2024). The results reveal differences in behaviour among the monitored springs. Cheserod, Mascognaz and, to a lesser extent, Entrebin show relatively buffered discharge regimes, whereas Gabiet and Promise display stronger interannual variability. Promise shows a marked increase in discharge in recent years, suggesting changes in recharge dynamics or hydrological functioning. Comparative analyses highlight heterogeneous responses to climatic variability, confirming that Alpine groundwater systems are site-dependent. Graphical tools such as heatmaps, bubble charts and Olympic-pool equivalents were used to facilitate the communication of hydrogeological results to non-specialist audiences. The findings underscore the importance of continuous spring monitoring for both scientific understanding and the sustainable management of drinking-water supplies under changing climatic conditions.