Groundwater salinisation is a serious problem affecting numerous areas of the world, and Neretva's delta in Croatia is one of them. Airborne electromagnetics is already widely used to feed data-driven decision and management processes with accurate (hydro)geomodels and, by doing so, to mitigate the detrimental effects of salinisation. In this perspective, in 2021, an airborne electromagnetic survey was flown over about 100 km 2. The overall goal of the survey was to better understand the hydrogeology of the plain leading to a more quantitative assessment of the saltwater intrusion and possible preferential paths. Here, we present the results of data processing and inversion. We built a (pseudo-)3D resistivity model based on 1D forward approximation. And we compare it against ground-based electrical measurements. According to the available boreholes, freshwater is related to a relatively resistive unit.

Open-Access Online Publication: November 1, 2023