The hyporheic zone represents the interface between surface water (SW) and groundwater (GW), where complex exchange processes, geochemical reactions, and biochemical processes occur, influencing water quality and aquifer recharge dynamics. In coastal aquifers affected by saltwater intrusion, such as the Muravera aquifer in Southeast Sardinia, understanding SW-GW interactions is crucial for effective groundwater management. This study aims to characterise the hyporheic zone along the Flumendosa River in the alluvial plain, where the Muravera multi-aquifer system is located, assessing water exchange patterns and geochemical processes to support the implementation of both active and passive interventions. The monitoring campaign conducted in this study involved the installation of mini piezometers at various locations along and across the main flow direction of the Flumendosa River to monitor vertical variations in the hyporheic zone (Wanty and Winter, 2000). In some locations, mini piezometers were installed in pairs at different depths, 100 and 200 cm, to better understand the vertical hydraulic gradients and exchange processes. Water samples were collected from mini piezometers and surface water sources to compare hydrochemical properties. In situ measurements of electrical conductivity, temperature, pH, and redox potential (Eh) were also carried out for both hyporheic and surface waters. Piezometric head levels were recorded to identify gaining and losing stream conditions, which provided insights into SW-GW interactions. Laboratory analyses focused on the chemical composition of the sampled waters to identify geochemical reactions in the hyporheic zone. By identifying gaining and losing stream sections, the study helps to find areas where interventions can be implemented to enhance groundwater recharge and mitigate saltwater intrusion. Additionally, it provides baseline data essential for evaluating the feasibility of Managed Aquifer Recharge (MAR) techniques as active measures for aquifer restoration. The research improves our understanding of hyporheic exchange processes, which in turn supports the development of targeted water management strategies incorporating both passive and active solutions. The investigation of the hyporheic zone in the lower Flumendosa valley has proven valuable for enhancing the understanding of the hydrogeological and hydrological dynamics of the area. This study supports the development of sustainable groundwa-ter management strategies, contributing to the long-term resilience of the Muravera aquifer.
Investigating hyporheic zone dynamics in the lower Flumendosa River valley (SE Sardinia, Italy) for groundwater resource management
Piscedda F. A.Primo
;Arras C.;Porru M. C.;Podda F.;Musu E.;Biddau R.;Vacca S.;Da Pelo S.
Ultimo
2025-01-01
Abstract
The hyporheic zone represents the interface between surface water (SW) and groundwater (GW), where complex exchange processes, geochemical reactions, and biochemical processes occur, influencing water quality and aquifer recharge dynamics. In coastal aquifers affected by saltwater intrusion, such as the Muravera aquifer in Southeast Sardinia, understanding SW-GW interactions is crucial for effective groundwater management. This study aims to characterise the hyporheic zone along the Flumendosa River in the alluvial plain, where the Muravera multi-aquifer system is located, assessing water exchange patterns and geochemical processes to support the implementation of both active and passive interventions. The monitoring campaign conducted in this study involved the installation of mini piezometers at various locations along and across the main flow direction of the Flumendosa River to monitor vertical variations in the hyporheic zone (Wanty and Winter, 2000). In some locations, mini piezometers were installed in pairs at different depths, 100 and 200 cm, to better understand the vertical hydraulic gradients and exchange processes. Water samples were collected from mini piezometers and surface water sources to compare hydrochemical properties. In situ measurements of electrical conductivity, temperature, pH, and redox potential (Eh) were also carried out for both hyporheic and surface waters. Piezometric head levels were recorded to identify gaining and losing stream conditions, which provided insights into SW-GW interactions. Laboratory analyses focused on the chemical composition of the sampled waters to identify geochemical reactions in the hyporheic zone. By identifying gaining and losing stream sections, the study helps to find areas where interventions can be implemented to enhance groundwater recharge and mitigate saltwater intrusion. Additionally, it provides baseline data essential for evaluating the feasibility of Managed Aquifer Recharge (MAR) techniques as active measures for aquifer restoration. The research improves our understanding of hyporheic exchange processes, which in turn supports the development of targeted water management strategies incorporating both passive and active solutions. The investigation of the hyporheic zone in the lower Flumendosa valley has proven valuable for enhancing the understanding of the hydrogeological and hydrological dynamics of the area. This study supports the development of sustainable groundwa-ter management strategies, contributing to the long-term resilience of the Muravera aquifer.
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