Mapping regional land displacements in the Venice coastland by an
integrated monitoring system
P. Teatini
Dept. Mathematical Methods and Models for Scientific
Applications, University of Padova, Padova, Italy
L. Tosi, L. Carbognin, F. Rizzetto
Istituto per lo Studio della Dinamica delle Grandi Masse, CNR, Venezia,
Italy
T. Strozzi, U. Wegmuller
Gamma Remote Sensing, Muri (BE), Switzerland
An original integrated monitoring method is designed to infer an accurate and reliable figure of
regional land displacements in coastal
areas where the presence of internal waters, wetlands, farmlands, urban and industrial centers
usually reduces the efficiency of single groundbased
and satellite-based measuring techniques. Five different methods, i.e. spirit leveling, Differential
Global Positioning System (DGPS),
Continuous GPS (CGPS), Interferometric Synthetic Aperture Radar (InSAR), and Interferometric Point
Target Analysis (IPTA), are
integrated into a Subsidence Integrated Monitoring System (SIMS) to overcome the limits characterizing
each technique. The SIMS has been
used over the past decade to provide a new image of the land displacements in the Venice region.
The result exhibits a resolution never
obtained before. The central lagoon, including the city of Venice, shows a general stability while the
northern and southern lagoon extremities
and their related catchment sectors sink with serious rates averaging 3 to 5 mm/year. The sinking rates
increase up to 10–15 mm/year in the
coastland south of the lagoon. Relatively small uplifts (less than 1 mm/year) are observed at the
Alpine foothills and in a wide area comprised
between the Euganean Hills and the lagoon. The observed land displacements have been associated to
the geological features of the study
region, i.e. tectonics, seismicity, differential consolidation of the middle–upper Pleistocene and
Holocene deposits, and to anthropogenic
activities, such as land reclamation and groundwater withdrawal.