Land motion detection in central Rwanda using small baseline subset interferometry

Abstract

Synthetic Interferometric Aperture Radar (InSAR) is a cost-effective technique for observing the Earth's surface, topography and ground motion deformations of the Earth. However, little work has been done in developing countries to apply this technique to the monitoring of natural disasters that strongly affect their socioeconomic condition. In this work, we apply the Small BAseline Subset (SBAS) technique in central Rwanda. This article presents the monitoring of earthflows in central Rwanda using 26 Sentinel–1 radar data extended from 2014 to 2018. The site investigation by high-resolution optical imagery from Google Maps is compared to the SBAS velocity. The results revealed an active earthflow near a mining area with a mean velocity around -30 to -20 mm/year and an earthflow of -40 mm/year mean velocity in Kigali. The other movements detected were due to anthropogenic and coastal subsidence.