Room: 302, East Quadrangle
Telephone: +44 (0) 141 330 5447
Fax: +44 (0) 141 330 4894
Email: a.singleton.1@research.gla.ac.uk Personal website: Not available
Research title
Advanced space geodesy techniques for landslide hazard mapping in the Three Gorges Region, China.
Summary of research
Interferometric Synthetic Aperture Radar (InSAR) is an imaging technique capable of measuring the topography of the Earth’s surface (and its changes over time) from space. The principle of interferometry exploits phase differences between separate SAR images and can measure surface deformation with millimetric precision and tens of metres horizontal spatial resolution over very large regions (e.g. 100 x 100 km). With its day/night and all-weather imaging capability, InSAR has transformed radar remote sensing from a largely interpretative science to a quantitative tool (Rosen et al., 2000). As such, InSAR techniques are increasingly employed to gain insights into geophysical and engineering processes such as earthquakes; landslides; volcanoes; and structural deformation of infrastructure.
The Three Gorges, China, are located in the middle of the Yangtze River covering a length of 193 km running between Fengjie and Yichang (see map). Landslides are a major hazard in the region due to steep slopes, heavy summer rainfall and human activity. The construction of the Three Gorges Dam may have increased the risk of landslides due to bi-annual water-level fluctuations of the 600 km long reservoir and the forced upslope relocation of towns to potentially unstable land. Field-based methods have monitored active landslides but they are limited by spatial coverage. InSAR techniques therefore provide the capability for surveying very large areas at a comparable level of precision to ground-based GPS measurements.
As a space geodetic technique, InSAR is limited by temporal decorrelation and atmospheric effects. In the Three Gorges region, InSAR is particularly limited by steep slopes, dense vegetation and localised water vapour variations. Therefore this research aims to:
Develop a reliable InSAR processing chain to identify and monitor active landslides in the Three Gorges region, focusing on the non-urban areas in particular;
Optimise InSAR Time Series algorithms to make it possible to process multiple images with a wide coverage;
Model slope stability in stable and active areas to assess the geophysical mechanisms responsible for slope instability;
Understand the relationship between active landslides and local geological structures (faults);
Provide a quantitative hazard assessment for this region.
Developing and validating technology for direct monitoring of landslide hazards should enable improved warning systems, infrastructure design and land-use planning.
Li, Z., Pasquali, P., Cantone, A., Singleton, A., Funning, G., and Forrest, D. 2012. MERIS atmospheric water vapor correction model for Wide Swath Interferometric Synthetic Aperture Radar. IEEE Geoscience and Remote Sensing Letters 9(2): 257 - 261doi:10.1109/LGRS.2011.2166053 >>
