Land Subsidence Monitoring in Australia and China using Satellite Interferometry

Continued excessive extraction of groundwater may lead to significant land subsidence, which causes economic loss. The aim of this research is to investigate ground subsidence in several Australian capital cities using the Persistent Scatterer Interferometry approach. Such studies may help improve our understanding of the deformation of terrain and built structures, and evaluate the effectiveness of any measures taken to ease the problem. The Persistent Scatterer Radar Interferometry approach is an alternative technique for land subsidence monitoring to conventional surveying methods. The Persistent Scatterer Interferometry approach first identifies all the stable point scatterers and a deformation analysis is then applied to these points. Persistent Scatterer InSAR techniques can generate deformation time-series with an accuracy down to the millimetre level depending on the number and quality of SAR images. The Persistent Scatterer InSAR results are validated with other spatial data such as groundwater extraction bore sites and groundwater level. Six cities are selected for these analyses, and the results show that the deformation rate from cities with groundwater significant levels of water extraction are much larger than for those cities with low levels of groundwater extraction.