Saltwater intrusion management at different coastal aquifers bed slopes considering sea level rise and reduction in fresh groundwater storage

Abstract

Coastal fresh groundwater management is a challenging research topic due to the relevance of these resources and the huge suffered risks due to global change and overpopulation. The geometrical features of coastal aquifers play a control role in saltwater intrusion (SWI). Seawater level rise and the reduction in aquifer fresh groundwater storage are promoting SWI. All these key factors are considered with two different numerical approaches defining schematic management criteria bottom using the numerical code SEAWAT. The former approach adopts the well-known Henry’s problem; the latter is based on the real study case of the Gaza aquifer (Palestine). Different aquifer bed slopes (ABS), and hydraulic and physical methods for SWI management are considered together with SLR, recharge reduction, and over pumping. The results showed that the land side ABS cases show more SWI than sea side and horizontal ABS. Cut-off walls and check dams are effective to manage SWI in horizontal ABS more than in other slopes, also the subsurface dams, earth fill and recharge of freshwater are good methods in land side ABS while the abstraction of brackish water and combination of recharge with abstraction are better to mitigate of SWI in sea side ABS. Useful comparing tables and considerations are defined with the purpose to guide the preliminary selections of new management solutions for reducing the effect of the global change on groundwater resources for different slopes aquifers around the coastal world. Graphical abstract

Quaternary climatic events as conditioning factors of hydrogeologic characteristics and salinity in costal aquifers at northern Patagonia, Argentina

“…Particularly in coastal areas, predictions of sea-level changes indicate that there will be a global sea-level rise that will cause a saline water intrusion into coastal aquifers. This has led to an increasing number of studies investigating the impact of sea-level rise on groundwater resources (e.g., Werner and Simmons, 2009; Chang et al, 2011; Colombani et al, 2016; Moore and Joye, 2021; Abd-Elaty and Polemio, 2023), even though all these works develop future projections without analyzing the clues that past changes can give us to achieve a better comprehension of the hydrogeologic system. Today, studying how Quaternary geologic–geomorphological–climatic evolution conditions groundwater salinization processes is essential, not only to know past conditions but also to predict future scenarios.…”