C-BAND D-INSAR AND FIELD DATA FOR CALIBRATING A GROUNDWATER FLOW AND LAND SUBSIDENCE MODEL

摘要

Differential Synthetic Aperture Radar Interferometry (D-InSAR) is a powerful technique used for detecting and measuring surface deformation with sub-centimetre accuracy. Using C-band data from three different satellites, the D-InSAR technique is used to calibrate a coupled groundwater flow and land subsidence numerical model. Additionally, D-InSAR results from different sensors are compared and contrasted. When comparing D-InSAR results with extensometers and water levels, a direct correlation is nociced. For all D-InSAR image pairs, large baselines, atmospheric effects, temporal decorrelation, and vegetative cover were limiting factors in obtaining a maximum number of usable interferograms. The total maximum subsidence for a point location in the valley between November 2003 and May 2008 is approximately 40 cm reaching a maximum total subsidence of over 2.0 metres since 1962. When contrasting the ENVISAT ASAR and RADARSAT-1 data, subsidence rates were similar yet the distribution had significant differences. Additionally, ENVISAT's shorter baselines led to more accurate results.