Estimation of coastal aquifers vulnerability to seawater intrusion due to Climate Change

Da Pelo S

;Porru MC;Westenbroek S;Nielsen M;Caracciolo D

2021-01-01

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Abstract

Saltwater intrusion is a crucial environmental problem in coastal areas. The preservation and proper management of water resources is essential in these systems. Climate change can affect natural recharge of aquifers and sea level variation. However, the relative vulnerability of coastal aquifers to groundwater extraction and sea-level rise need to be considered in order to quantify which of these factors have the most significant impact and better manage groundwater to protect it from saltwater intrusion. The trend of saline intrusion will be simulated in the test area of the Muravera plain in Sardinia (Italy). In this area, the natural hydrodynamic equilibrium between groundwater, surface-water and seawater has been deeply modified by the construction of two dams across the Flumendosa river and the development of agriculture, tourism and aquaculture activities along the coast. In this work, the possible future scenarios of natural recharge of the aquifers in relation to climate change will be assessed through the use of Soil Water Balance (SWB) code. Moreover, the vulnerability of coastal aquifers to saltwater intrusion and variation in natural groundwater discharge caused by rising sea levels and in relation to abstraction will be examined. Monitoring systems of hydrogeological, geochemical and isotopic indicators will be designed to improve the qualitative and quantitative knowledge of groundwater in relation to the impact that climate change will have on the natural recharge of aquifers. These strategies could be extended at a regional level on coastal aquifers with similar hydrogeological behaviour.