Scheda di dettaglio – i prodotti della ricerca
| Dato | Valore |
|---|---|
| Title | A conceptual model for a fractured volcanic aquifer to investigate the role of climate variabilty and water withdrawal on recent changes |
| Abstract | The Alcantara River Basin is located in North-Eastern Sicily (Italy), encompassing the north side of Etna Mountain, the tallest active volcano in Europe. On the right-hand side of the river, the mountain area is characterized by volcanic rocks with a very high infiltration. Here, precipitation and snow melting supply a big aquifer whose groundwater springs at the mid/downstream of the river, mixing with surface water and contributing to feeding the river flow also during the dry season. In the upstream a maximum of 520 l/s are extracted for municipal use through wells and an infiltration gallery supplying the Alcantara Aqueduct. In summer 2020 and 2021, the river suffered a prolonged dry phenomenon in the middle-valley stretch with a serious loss of fish fauna, due to significant spring depletion along the stream most likely determined by a meteorological drought. Since this anomaly is of great concern, the need arises to better understand whether the interaction between the water abstraction to supply the Alcantara aqueduct and the natural recharge of the aquifer is compatible with maintaining the balance of aquatic ecosystems in the middle-downstream valley of the Alcantara River also during dry years; or if the observed changes may also be partly due to other mechanisms, such as illegal or unaccounted water abstractions or hydrogeological modification due to the volcanic activity. To this end, in this study, an attempt was made to analyze changes in the groundwater level and in the interconnection between surface and groundwater by using the widely accepted MODFLOW 6, a finite-difference numerical model that in principle can provide constraints to reduce uncertainty and address field activity in data scarce case studies. The model was calibrated in steady state by comparing simulated and observed water heads as well as the groundwater budget. Then the simulation was run in transient mode for the period 2014-2021. The model outcome showed a depletion rate compatible with the one observed during the recent dry summers, thus suggesting that more sustainable and comprehensive strategies, also including groundwater extraction regulations, should be implemented to preserve this natural resource for in-stream water use and ecosystem services. |
| Source | European Geosciences Union, 2023, Vienna, 23/04/2023-28/04/2023 |
| Keywords | numerical modelvolcanic aquiferMount Etna |
| Year | 2023 |
| Type | Poster |
| Authors | Brunella Bonaccorso1, Marco Silipigni1, Cristina Di Salvo2, Iolanda Borzì1, Elisabetta Preziosi3 |
| Text | 481634 2023 numerical model volcanic aquifer Mount Etna A conceptual model for a fractured volcanic aquifer to investigate the role of climate variabilty and water withdrawal on recent changes Brunella Bonaccorso1, Marco Silipigni1, Cristina Di Salvo2, Iolanda Borzi1, Elisabetta Preziosi3 1 Universita degli studi di Messina 2 CNR IGAG 3 CNR IRSA The Alcantara River Basin is located in North Eastern Sicily Italy , encompassing the north side of Etna Mountain, the tallest active volcano in Europe. On the right hand side of the river, the mountain area is characterized by volcanic rocks with a very high infiltration. Here, precipitation and snow melting supply a big aquifer whose groundwater springs at the mid/downstream of the river, mixing with surface water and contributing to feeding the river flow also during the dry season. In the upstream a maximum of 520 l/s are extracted for municipal use through wells and an infiltration gallery supplying the Alcantara Aqueduct. In summer 2020 and 2021, the river suffered a prolonged dry phenomenon in the middle valley stretch with a serious loss of fish fauna, due to significant spring depletion along the stream most likely determined by a meteorological drought. Since this anomaly is of great concern, the need arises to better understand whether the interaction between the water abstraction to supply the Alcantara aqueduct and the natural recharge of the aquifer is compatible with maintaining the balance of aquatic ecosystems in the middle downstream valley of the Alcantara River also during dry years; or if the observed changes may also be partly due to other mechanisms, such as illegal or unaccounted water abstractions or hydrogeological modification due to the volcanic activity. To this end, in this study, an attempt was made to analyze changes in the groundwater level and in the interconnection between surface and groundwater by using the widely accepted MODFLOW 6, a finite difference numerical model that in principle can provide constraints to reduce uncertainty and address field activity in data scarce case studies. The model was calibrated in steady state by comparing simulated and observed water heads as well as the groundwater budget. Then the simulation was run in transient mode for the period 2014 2021. The model outcome showed a depletion rate compatible with the one observed during the recent dry summers, thus suggesting that more sustainable and comprehensive strategies, also including groundwater extraction regulations, should be implemented to preserve this natural resource for in stream water use and ecosystem services. Published version European Geosciences Union, 2023 Vienna 23/04/2023 28/04/2023 Internazionale Contributo A conceptual model for a fractured volcanic aquifer to investigate the role of climate variabilty and water withdrawal on recent changes poster egu 2023.pdf Poster elisabetta.preziosi PREZIOSI ELISABETTA cristina.disalvo DI SALVO CRISTINA |