Hydrogeological assessment of a major spring discharging from a calcarenitic aquifer with implications on resilience to climate change

Maria Filippini; Stefano Segadelli; Enrico Dinelli; Michele Failoni; Christine Stumpp; Gianluca Vignaroli; Tommaso Casati; Beatrice Tiboni; Alessandro Gargini

doi:10.1016/j.scitotenv.2023.169770

Hydrogeological assessment of a major spring discharging from a calcarenitic aquifer with implications on resilience to climate change

Sci Total Environ. 2024 Feb 25:913:169770. doi: 10.1016/j.scitotenv.2023.169770. Epub 2024 Jan 3.

Authors

Maria Filippini¹, Stefano Segadelli², Enrico Dinelli³, Michele Failoni³, Christine Stumpp⁴, Gianluca Vignaroli³, Tommaso Casati³, Beatrice Tiboni³, Alessandro Gargini³

Affiliations

¹ Department of Biological, Geological, and Environmental Sciences - BiGeA, Alma Mater Studiorum University of Bologna, via Zamboni, 67, 40126, Bologna, Italy. Electronic address: maria.filippini3@unibo.it.
² Geological, Seismic and Soil Service, Emilia-Romagna Region Administration, Viale della Fiera 8, 4027 Bologna, Italy.
³ Department of Biological, Geological, and Environmental Sciences - BiGeA, Alma Mater Studiorum University of Bologna, via Zamboni, 67, 40126, Bologna, Italy.
⁴ University of Natural Resources and Life Sciences, Vienna, Department of Water, Atmosphere and Environment, Institute of Soil Physics and Rural Water Management, Muthgasse 18, 1190 Vienna, Austria.

PMID: 38176553
DOI: 10.1016/j.scitotenv.2023.169770

Abstract

Groundwater is a vital source of freshwater, serving ecological, environmental, and societal needs. In regions with springs as a predominant source, such as the Northern Apennines (Italy), resilience of these springs to climate-induced recharge changes is crucial for water supply and ecosystem preservation. In this study, Nadìa Spring in the Northern Apennines is examined through an unprecedented array of multidisciplinary analyses to understand its resilience and unique characteristics. The Nadìa Spring's exceptional response, characterized by a sustained base flow even in the face of drought, is attributed to a combination of factors including a substantial groundwater reservoir, a complex network of faults/fractures, slope instabilities, and karst dissolution. The investigation reveals a dual porosity system in the aquifer, consisting of fast-flow conduits and a diffuse fracture network. While fast-flow conduits contribute to rapid responses during high-flow conditions, the diffuse system becomes predominant during low-flow periods. This dual porosity structure helps the spring maintain a consistent base flow in the face of climate-induced recharge fluctuations. The study shows that Nadìa Spring exhibits remarkable resilience to year-to-year variations in recharge, as evidenced by stable minimum discharge values. While the spring has undergone a decline in discharge over the past century due to long-term climate change, it is becoming more resilient over interdecadal timescales due to transition to a diffuse drainage system that mitigates the impact of reduced recharge. The availability of a century-long spring discharge monitoring was a crucial piece of information for understanding the spring's discharge response and drawing conclusions about its long-term resilience to recharge fluctuations. Continuing long-term monitoring and research in the future will be essential to validate and expand upon these findings in the context of changing climatic conditions. This research serves as a model for assessing strategic groundwater discharge points in geological settings similar to the Northern Apennines.

Keywords: Fractured aquifer; Northern Apennines; Recharge decrease; Resilience; Spring discharge.