Monitoring subsidence of open pit iron mines at Carajás Province based on SBAS interferometric technique using TerraSAR-X data

Abstract

This work aims to investigate the potential of the Small Baseline Subset (SBAS) to measure ground deformation in five open pit iron mines located in Carajás Mineral Province (Brazilian Amazon Region), characterized by torrential rains, using a set of 33 TerraSAR-X Stripmap images acquired during 1-year, from March 2012 to April 2013. For the interferometric processing, a coherence threshold of 45%, 4 looks, Delaunay Minimum Cost Flow (MCF), with a reference GeoEye-1 DEM were used. The SBAS measurements allowed obtaining a synoptic view of the mine complex, covering the infrastructure and benches, detecting the expected natural settlements on the top of waste piles, as well as detecting the deformation in some benches of one mine (N5W). Overall, the results were consistent with the in situ measurements, and so can be a useful tool for monitoring linear and nonlinear deformation in open pit mines located in a tropical rainforest environment, providing a synoptic view of the ground movement for alarm, planning and mining risk assessment.