Deformation Monitoring and Analysis of the Geological Environment of Pudong International Airport with Persistent Scatterer SAR Interferometry

Abstract

Many coastal cities have undertaken reclamation projects to satisfy the land demands of rapid urbanization. However, the foundations of reclaimed land are susceptible to settlement and can have undesirable environmental impacts that could adversely affect these dense, populated areas. In the case of international airports built on reclaimed areas especially, regional-scale deformation must be monitored to ensure operational security for public safety. Persistent Scatterer SAR Interferometry (PSI) technology has proven to be an effective tool to detect ground deformation in urban areas. However, it is still a challenge to apply PSI to effectively monitor settlement at airports built on newly developed coastal reclamation areas because of the scarcity of identifiable targets. Moreover, additional issues arise as the complicated deformation patterns associated with the underlying geological conditions make it difficult to interpret InSAR-derived results. In this study, a time-series analysis of a high-resolution TerraSAR-X satellite image stack acquired from September 2011 to October 2012 was performed by employing a modified PSI technique to retrieve the mean deformation velocity and time series of surface deformation at Pudong International Airport. Qualitative evaluation of spatial distribution and temporal evolution of deformation was conducted by joint analyses of deformation measurements and local geological data. Detailed analysis of various driving forces for deformation patterns confirmed that the results of deformation monitoring obtained by PSI are reliable and consistent with that of local geological surveys. Since the factors responsible for the subsidence within the airport are still at play, ongoing and routine deformation monitoring is warranted.

The 2015–2016 Ground Displacements of the Shanghai Coastal Area Inferred from a Combined COSMO-SkyMed/Sentinel-1 DInSAR Analysis

“…The analysis of Figure 9 reveals that reconstructed east-west deformation signals over the ocean-reclaimed land are (on average) less prevalent with respect to the up-down deformation signals recorded in homologous locations. The detected vertical movements are the effects on the ground of the consolidation mechanisms of the soils used for the reclamation of land from the ocean, and have also been investigated in previous studies [28,32]. This outcome is in general agreement with the results of studies [27,31], based upon considerations of the geology of the area and on the mechanisms of soil consolidation in reclaiming land.…”

“…Its western sector, as already anticipated by previous studies [28,32], based on the use of ASAR/ENVISAT SAR data (from 2007 to 2010) and COSMO-SkyMed data (from 2014 to 2016), was almost stable from 2015 to 2016 with maximum up-down and east-west deformation rates of a few millimeters per year (see for instance the plots relevant to points (e) and (f) shown in Figure 9).…”

“…Its western sector, as already anticipated by previous studies [28,32], based on the use of ASAR/ENVISAT SAR data (from 2007 to 2010) and COSMO-SkyMed data (from 2014 to 2016), was Figure 9. Plots of the east-west (blue triangles) and up-down (red triangles) time-series relevant to ground points labeled as (a-h) in Figure 8.…”

“…To the best of our knowledge, this represents the first direct evidence of the negligibility of lateral movements in reclaimed land documented through DInSAR-based approaches. As a future perspective, we plan to extend the presented analyses in the next few years to corroborate the validity of the foreseen deformation models discussed in [28,32]. An important point of criticism, however, needs to be raised: the European Space Agency acquisition plan of Sentinel-1A SAR data over the Shanghai area through descending orbits (which combined with the ascending data could allow a continuous mapping of the 2D displacements of the imaged areas) is not regular as in the ascending S1-A dataset.…”

Application of DInSAR-PSI Technology for Deformation Monitoring of the Mosul Dam, Iraq

“…The measurement of deformation patterns might be used as a warning of potential safety problems in dams and other infrastructures. It also helps decision makers in adopting appropriate measures to prevent losses [67]. The safety problems assume critical importance for earth-fill dams constructed on soluble evaporitic rocks.…”