Advanced DINSAR analysis on dam stability monitoring: A case study in the Germano mining complex (Mariana, Brazil) with SBAS and PSI techniques

This work presents an investigation of detection and monitoring of surface motions using Advanced Differential SAR Interferometry (A-DInSAR) with SBAS (Small Baseline Subset) and PSI (Persistent Scatterer Interferometry) techniques in the Germano iron mining complex region (Mariana, Brazil), after the collapse of the Fundao tailing dam occurred on November 5th, 2015. The research was carried out aiming to provide useful information about ground movement monitoring, planning and risk assessment in the area after the tragic event. The analysis was performed using 46 TerraSAR-X images and a Digital Elevation Model (DEM) obtained by Pleiades data. A-DInSAR processing provided the removal of the atmospheric phase artifacts, baseline related errors, DEM height error estimation and finally the ground displacement determination. The results pointed out that with both techniques it was possible to assess the stability conditions of the Germano mining assets, particularly the main structures of the Germano dam and the detection of small settlements in the mining tailings storage, pointing out that these may be an important components for risk management of open pit mining operations, including tailings dams.