Land Subsidence in Coastal Environments: Knowledge Advance in the Venice Coastland by TerraSAR-X PSI

Abstract

The use of satellite SAR interferometric methods has significantly improved the monitoring of ground movements over the last decades, thus opening new possibilities for a more accurate interpretation of land subsidence and its driving mechanisms. TerraSAR-X has been extensively used to study land subsidence in the Venice Lagoon, Italy, with the aim of quantifying the natural and anthropogenic causes. In this paper, we review and update the main results achieved by three research projects supported by DLR AOs (German Aerospace Center Announcement of Opportunity) and conducted to test the capability of TerraSAR-X PSI (Persistent Scatterer Interferometry) to detect ground movements in the complex physiographic setting of the Venice transitional coastal environment. The investigations have been focused on the historical center of Venice, the lagoon inlets where the MoSE is under construction, salt marshes, and newly built-up areas in the littoral. PSI on stacks of stripmap TerraSAR-X images covering short- to long-time periods (i.e., the years 2008–2009, 2008–2011 and 2008–2013) has proven particularly effective to measure land subsidence in the Venice coastland. The very high spatial resolution (3 m) and the short repeat time interval (11 days) of the TerraSAR-X acquisitions make it possible to investigate ground movements with a detail unavailable in the past. The interferometric products, properly calibrated, allowed for a millimetric vertical accuracy of the land movements at both the regional and local scales, even for short-term analyses, i.e., spanning one year only. The new picture of the land movement resulted from processing TerraSAR-X images has significantly contributed to update the knowledge on the subsidence process at the Venice coast.

The 2019 Flooding of Venice and Its Implications for Future Predictions

“…Current estimates are that sea level is rising at 3.5 mm yr -1 (Ablain et al, 2019), but that figure is steadily increasing (Clarck et al, 2016). When combined with 1.5 mm yr -1 of land subsidence (Tosi et al, 2018), Venice is now losing 5 mm yr -1 with respect to the sea. More extreme floods are expected, as well as more "regular" floods.…”

Advances and Practices on the Research, Prevention and Control of Land Subsidence in Coastal Cities

“…(6) Significant settlements of a few centimetres per year have been detected at the three inlets where new structures and restoration works were carried out (Tosi et al, 2012. (7) Newly built-up areas induced local land subsidence with sinking rates up to three times higher than those characterizing the older urban areas (Da Lio and Tosi et al, 2018).…”

Multi-Scale and Multi-Dimensional Time Series InSAR Characterizing of Surface Deformation over Shandong Peninsula, China

“…Land subsidence caused by either natural or anthropogenic factors has become one of the serious environmental problems around the world regarding population expansion and economic growth, among which the coastal subsidence phenomenon is reported frequently in many countries, such as in Shenzhen and Xiamen (China), Urayasu (Japan), Sibari and Venice (Italy), Houston and New Orleans (USA) [1][2][3][4][5][6][7][8]. Land subsidence makes coastal areas more vulnerable to coastal flooding, saltwater intrusion, shoreline erosion and infrastructure damage.…”

“…Multi-temporal InSAR techniques, such as Persistent Scatterers InSAR (PSInSAR), Small Baseline Subset (SBAS) InSAR and SqueeSAR, have been developed to map land surface displacements by minimizing temporal/spatial decorrelation and the artifacts inherent in conventional InSAR [19,20]. The advanced time series InSAR techniques have facilitated coastal land subsidence monitoring in many regions [1][2][3][4][5]21]. Moreover, the InSAR technique shows its potential in large-scale deformation monitoring, e.g., on a regional scale or national scale with the increased availability of free-of-charge and commercial SAR datasets [22][23][24].…”