Around the world, areas near islands and coastlines frequently provide substantial potential for socio-economic development, which raises the need for freshwater resources. The increased demand, strictly related to tourism and agriculture activities, raises the possibility of aquifer overexploitation. A major challenge to the sustainability of groundwater supplies in coastal locations is the problem of seawater intrusion (SWI). In karst coastal aquifers, the evolution of hydrochemistry is rapidly impacted by SWI. Qualitative data integration can be one of the premises and a key to hydrochemistry evolution or seawater intrusion research under complex geological and hydrogeological conditions. This contribution focuses on a coastal strip along the Adriatic coast of south eastern Italy, positioned between two distinct groundwater systems. A total of 73 sampling sites were systematically monitored over a four-year period (2007–2010) to investigate the temporal evolution of the hydro-geochemical parameters within the region. This work aims at conducting a comprehensive analysis of SWI dynamics, evaluating historical, current, and projected future scenarios to better understand the mechanisms and impacts of SWI in the context of regional hydrogeological processes. To understand the past scenario for the seawater intrusion spatial mapping for single parameters and chemical indices, these were overlaid to create a seawater intrusion map (SWIM), coupled with a graphical plot and salinity profiles along the study area. The results show a strong correlation between total dissolved solids (TDS) and chlorine ion (Cl-) concentration. Meanwhile, the SWI pattern from spatial mapping over the study area shows diffusion transport reflected by an increase in brackish water facies area and a decrease in fresh and saline facies, respectively, over the monitoring period.Karst Aquifer, Seawater intrusion, water quality, hydrochemistry, spatiotemporal evolutions.