Shanghai Pilot Free Trade Zone (SPFTZ) is the first free trade zone in China, consisting of eight independent zones and located in Pudong New District. With the rapid development in the SPFTZ, frequent human activities may induce severe land subsidence. Based on time-series interferometric synthetic aperture radar (InSAR) technique and multitemporal C-band images, the temporal and spatial evolution of subsidence in Pudong New District is obtained from May 2016 to October 2020. The achieved results show that severe subsidence occurred in the east of the study area, where the maximum subsidence rate was −40 mm / year. Most of the land in the SPFTZ remained stable, but small-scale subsidence with a maximum subsidence rate of −18.1 mm / year occurred in two zones. InSAR-derived results are in good agreement with the manual measurements, with a root mean square error of 1.4 mm. Time-series analysis reveals that land subsidence in the SPFTZ mainly originates from urban constructions, including building construction and vehicle load. Meanwhile, the most severe subsidence occurred in the east of Pudong International Airport, which may be attributed to the airport renovation project. In a reclaimed area, land subsidence can be classified into different construction periods, which gradually weakens from north to south.
Over the last two decades, Synthetic Aperture Radar Interferometric (InSAR) has proven a remarkable potential tool for
observing the Earth surface, especially for mapping the Earth's topography and deformation. It can resolve surface
displacement with centimetric accuracy, tens meters of spatial resolution and monthly temporal resolution. The
permanent scatterer (PS) technique has been developed later in the 1990s first by A. Ferretti to overcome the major
limitations of repeat-pass SAR interferometry: temporal and geometrical decorrelation as well as atmospheric delays.
The Ferretti's method, referenced as the Permanent Scatterers TechniqueTM in their patented procedure, works best in
urban areas containing large numbers of man-made structures, which tend to be angular and often produce very efficient
reflectors that dominate background scattering. In this paper, a series of fifteen ENVISAT ASAR acquisitions of the city
of Nantong, located at the mouth of Yangtze River adjacent to Shanghai, covering the period from 2006 to 2007, was
analyzed. The PS-InSAR technique and Geographic Information System (GIS) spatial analysis were used to detect
ground deformation in the urban area. Results show there was no large, continuous subsidence occurs in the city,
however seven subsidence bowls were found. This can be used to define the risk zones for future ground subsidence.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.