New insights into fast ground subsidence in southern Saskatchewan from modeling of RADARSAT-2 DInSAR measurements / [by] S.V. Samsonov ... [et al.]. : M104-9/2014-2E-PDF

With Radarsat-2 Differential Interferometric Synthetic Aperture Radar (DInSAR) we observed a fast (approximately -10 cm/year) ground subsidence in southern Saskatchewan, affecting some limited areas located between Rice Lake and the city of Saskatoon. The deformation maps were calculated using 2008-2013 RADARSAT-2 SAR data from two different beams: Multi-Looked Fine and Standard. We performed standard InSAR analysis and reconstructed two dimensional, east-west and vertical time series of ground deformation with the Multidimensional Small Baseline subset (MSBAS) method (Samsonov and d'Oreye, 2012). Analysis of the MF3F and S3 time series revealed that the subsidence rate is nearly constant during the entire observation period, which suggests that it is not related to groundwater withdrawal that should have been affected by seasonal variations. We further selected highly coherent ascending and descending interferograms spanning November 2011 - April 2011 for simple elastic modelling. The inversion solves for several parameters, including source depth, precise location and volume change rate. Two regions of subsidence with nearly circular shapes were analyzed. The elastic modelling of the observed deformation is consistent with volume changes of spherical and/or sill-like sources at source depths ranging from 600 to 1500 m. We also investigated the impact of this subsidence on the redistribution of surface water levels and its impact on farming.

Lien permanent pour cette publication :
publications.gc.ca/pub?id=9.815444&sl=1

• Format MARC XML
• Format MARC HTML

Demander des formats alternatifs