Different Ground Subsidence Contributions Revealed by Integrated Discussion of Sentinel-1 Datasets, Well Discharge, Stratigraphical and Geomorphological Data: The Case of the Gioia Tauro Coastal Plain (Southern Italy)

Groundwater is the main water supply for agricultural and industrial needs in many
coastal plains worldwide. Groundwater depletion often triggers land subsidence, which threatens
manmade infrastructure and activities and aggravates other geohazards. We applied a multi-temporal
interferometric synthetic aperture radar technique to Sentinel-1 datasets to detect ground motion in
the Gioia Tauro plain (Calabria, Southern Italy) from 2018 to 2021. The InSAR data were analysed
through the integrated use of groundwater head, stratigraphical and geomorphological data, and land
use information to distinguish the potential subsidence divers. The results show that subsiding areas,
with a mean rate of about 10 mm/yr, are in the middle of the plain, and their location is influenced by
the spatial distribution of compressible sediments included in the shallow aquifer. Furthermore, the
subsidence arrangement is spatially accordant with the main groundwater depression area, which
can be ascribed to the ongoing and increasing water pumping for predominantly agricultural usage.
We also observed that subsidence (up to 10 mm/yr) affects the western dock of the Gioia Tauro
harbour, in front of which, in very shallow water, are two submarine canyon heads already affected
by slides in the past.