Unsustainable use of groundwater resources in agricultural and urban areas: a persistent scatterer study of land subsidence at the basin scale

Multi-temporal analysis of space-borne radar images through Persistent Scatterer Interferometry (PSI) is exploited for mapping subsidence at basin scale in the Gioia Tauro plain (Italy), a densely urbanized coastal area whose land deformation are controlled by aquifer overexploitation. Both historical (1992-2001; ERS1/2 images) and present (2002-2006; ENVISAT images) scenarios are analyzed to solve the spatial variability and temporal evolution of ground displacements affecting the plain. Average deformation rates as high as 10-15 mm/yr are observed from 1992 to 2006, with highest velocities (i.e. 22.8 mm/yr) occurred between 1992 and 2000 within the central part of the basin, in the area of Rizziconi (5 km ESE of Gioia Tauro). The outcomes of this PSI study will support the future improvement of groundwater management and the implementation of best strategies for risk mitigation, land use planning, sustainable use of groundwater resources, and consequent reduction of economic and social impacts.