title: Hydrogeological and Geochemical Modelling of a seawater intrusion barrier in a coastal/island groundwater body
Creators: name: Demichele, Francesco
Publisher: name: TU Darmstadt
Year: 2024

description: The impact of Climate Change in the central Mediterranean Region is expected to result in a general reduction of the annual precipitation, coupled with an increased variability in precipitation events. This is expected to give rise to prolonged drought periods as well as reduced recharge levels to groundwater, increasing the existing pressures on these already stressed naturally renewable freshwater resources. On the other hand, an increased prevalence of high intensity rain events is expected to result in the over-availability of surface water resources during short time periods increasing the risk of flood events.
Ensuring a high level of resilience in the water sector is therefore increasingly becoming a priority for the Maltese islands, and this not only for ensuring security in the provision of water services but also in view of water’s contribution to food production and ecosystems. Increased resilience is generally addressed through the application of traditional tools such as water demand management and water supply augmentation measures. But it can also be addressed through the restoration and augmentation of the capacity of existing natural freshwater resources.
Managed Aquifer Recharge is therefore one of the tools which can support a move towards a more water resilient management framework, improving the quantitative (and qualitative) status of groundwater whilst enabling the reservoir capacity of aquifer systems to be exploited for balancing water storage between wet and dry periods. In so doing, additional water resources during wet periods for which there would be no effective use can be stored, enhanced and made available during dry periods when water resources are scarce – thereby ensuring the sustainability of groundwater resources and ensuring their contribution to water security in the Maltese islands for the future.
This thesis assesses feasibility of the application of a Managed Aquifer Recharge (MAR) Scheme to the Malta Mean Sea Level Aquifer system, an island (freshwater-lens system) body of groundwater which is of strategic importance to the water supply of the islands, but which has suffered a deterioration in status over the years due to long term over-abstraction. The potential impact of a Managed Aquifer Recharge scheme in the central and southern regions of this aquifer system is assessed as a tool for improving the quantitative and qualitative status of the groundwater body with a view of guiding the development of policy considerations for the application of Managed Aquifer Recharge as a tool within Malta’s future River Basin Management Plans for sustaining groundwater resources. 
The evaluation of the suitability of a MAR scheme to halt further depletion of the Malta groundwater resources was based on the assessment of current social and local environmental settings. Due to fast urbanisation, water demand is rising rapidly while securing a safe drinking water supply becomes a challenge. Together with land consumption, high evapotranspiration rates typical of semi-arid regions compromise the implementation of typical MAR schemes such as infiltration spreading methods. To overcome the quantitative and qualitative challenges related to water management of the country, mitigation and adaption measures suitable for the site-specific conditions of Malta are needed to compensate the effects of groundwater exploitation associated to saltwater intrusion into the freshwater lens system.