Monitoring of the saline wedge in the rivers of the Ferrara province (Emilia Romagna region,Italy).

Saltwater intrusion threatens coastal ecosystems and water resources globally, intensified by
climate change. Rising sea levels and reduced river flows disrupt the water balance in estuarine
zones, allowing seawater to penetrate upstream into rivers and coastal aquifers. Studies predict a
9.1% global average increase in saltwater intrusion under high emissions scenarios, with extreme
events becoming up to 25 times more frequent [2]. The Po River Delta exemplifies this
vulnerability. The Ferrara area, characterized by minimal slopes and elevations mostly below sea
level, is particularly exposed. Projections indicate the Po di Goro estuary could experience up to
63% annual increase in saltwater intrusion, reaching 120% in summer [6]. The 2022 drought
demonstrated system fragility, with saltwater compromising irrigation and domestic water
supplies. Groundwater aquifers face additional stress from excessive extraction and reduced
natural recharge [1], affecting drinking water quality, agriculture, natural habitats, and soil
integrity. Traditional monitoring relies on point measurements of electrical conductivity using
boat-mounted probes, providing inadequate spatial and temporal resolution. Geophysical
methods—particularly electrical resistivity tomography (ERT) and electromagnetic (FDEM)
surveys—offer rapid, high-resolution alternatives. Previous research demonstrated the
effectiveness of combined ERT-FDEM approaches in the Po di Goro for monitoring saltwater
wedge advancement [4]. Integration of multiple geophysical techniques enables multi-scale
characterization [3].
This PhD project develops an integrated monitoring and predictive modeling system for saltwater
wedge intrusion in Ferrara, combining advanced geophysical methods with machine learning.
Building on long-term FDEM monitoring (2022-2025) in the Po di Goro, the project extends to
other Ferrara rivers and incorporates additional methods (ERT, GPR).
Expected outcomes include: (1) precise mapping of saltwater wedge extent, depth, and temporal
evolution; (2) machine learning-based predictive tools to forecast intrusion evolution; (3) decision-
support tools for sustainable water resource management, agriculture, and territorial planning,
with methodologies transferable to other estuaries globally.

The project addresses a critical gap: the absence of systematic monitoring systems and reliable
predictive tools. Increasing salinization frequency underscores the urgency for robust predictive
capabilities enabling preventive interventions. The project responds to the 2022 Po River basin
water crisis, offering practical solutions through informed policy on coastal defense, flood
mitigation, subsidence reduction, and intrusion control [5].
References
[1] Crestani, E. (2022). Large-Scale Physical Modeling of Salt-Water Intrusion. Water, 14(8), 1183.
[2] Lee, J., et al. (2025). Global increases of salt intrusion in estuaries. Nature Communications, 16,
3444.
[3] Mansourian, D., et al. (2022). Geophysical surveys for saltwater intrusion assessment. Journal
of the Earth and Space Physics, 48(3), 331–341.
[4] Rizzo, E., et al. (2023). DC and FDEM salt wedge monitoring of the Po di Goro river. EGU23-
5297.
[5] Simeoni, U. (2009). A review of the Delta Po evolution. Geomorphology, 107(1–2), 64–71.
[6] Verri, G., et al. (2024). Salt-wedge estuary's response to rising sea level. Frontiers in Climate, 6,
1408038.