Investigation on Tailing Dam Deformations using differential SAR Interferometry Techniques

Duration of the Thesis: 6 months
Completion: June 2020
Supervisor: M.Sc. Philipp Schneider
Examiner: Prof. Dr.-Ing. Uwe Sörgel

The collapse of a tailings dam can pose a great threat to both the environment and humans. This master thesis is aimed to investigate the different deformation patterns of collapsed and stable tailing dams using DInSAR technique. The SBAS method, which can mitigate spatial-temporal decorrelation comparing to other DInSAR techniques, is applied in the thesis. The analysis was performed using Sentinel-1 SAR images that are downloaded from Copernicus Open Access Hub from May 2015 to July 2019 with 5-by-20 meter resolution and a Digital Elevation Model obtained by SRTM with 90 meter resolution. Surprising patterns are discovered in the thesis: The SBAS signals on the stable tailing dam have a natural transition between uplift and subsidence part, while it is quite irregular and not continuously deformed on the collapsed tailing dam. The stable dams show continuous sinking patterns, in contrast, the collapsed dams have rise trend before the collapse and show an uneven deformation profile. The deformation along the dyke of stable tailing dam represents 'U' shape, but fluctuated much along the embankment of a ruptured dam. And the deformation across dykes of stable dam sunk gradually from toe to crest, however, the situation is totally different from the collapsed dam. These regular patterns might be useful to justify the stability of the tailings dam in a non-quantitative aspect.

Figure1 demonstrates an overview of the project process flow.