TTE286

Análisis de deformación (2015- 2017), ligado a la ocurrencia de remociones…

ABSTRACT

Presently, mass removal processes (MRP) have been increasing and a clear example of this

is what is happening in areas such as the Chilean Patagonia. Given this, studies related to

REM have been carried out, which has allowed acquiring a better knowledge of these

processes. Under this circumstances, a hillside of the western Yelcho range, located to the

NW of the town of Villa Santa Lucía (VSL), which in 2017 was affected by an MRP, was

considered as the area of analysis. As a result of this event, the interest arises to investigate

if prior to the debris flow, deformation precursors were recorded. In order to achieve the

objective, the SAR Persistent Scatterer technique was applied, provided by the

ENVI/SARscape software, where using C-band satellite images from the Sentinel-1 mission,

deformations on the Earth's surface can be detected. Subsequently, the data was post

processed, obtaining three displacement velocity maps and their respective time series.

Moreover, the deformation results were established in the following ranges: 1) -24 to -1

mm/year for negative deformations and, 2) 1 to 24 mm/year in the case of positive

deformations. Regarding the distribution of the DPs, no pattern of occurrence was observed,

but it was proved that the technique is effective in determining deformation precursors.

Another important finding was that the closer to the date of MRP occurrence, the closer the

DPs with negative strain values increased their displacement activity. Ultimately, and

considering the limitations of the method, it is established that the technique decreases its

accuracy in rugged topography, therefore, it is ideal to apply it to flatter and more regular

terrain.

Keywords: Persistent Scatterers (PSs), refinement, deformation, time series, displacement

velocity.

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