LANDSLIDE INVESTIGATION USING DIFFERENTIAL SYNTHETIC APERTURE RADAR INTERFEROMETRY: A CASE STUDY OF BALLORAN DAM AREA IN SYRIA

Abstract

Landslides are one of the main geological hazards that can cause critical damage to the infrastructure in an area and can result in serious risks to the people’s safety there. Landslides can be investigated and monitored using field survey, aerial mapping and high resolution optical satellite data analysis. However, these methods are relatively time-consuming. Interferometric synthetic aperture radar (InSAR) can investigate and monitor landslides and provide sub-centimetre accuracy for ground-surface deformation when time series analysis techniques are employed. In this research, differential synthetic aperture radar interferometry was applied on Sentinel-1 data of two Single Look Complex (SLC) images from 16 October 2018 and 21 March 2019 in the Interferometric Wide (IW) swath mode using the Sentinel application platform (SNAP) to determine the extreme ground-surface deformations, as a prelude to landslides occurrence in Balloran dam area in the north-west of Syria, where the ophiolite complex deposits of the Maastrichtian are exposed causing, due to the heavy rains, several landslides affecting the road network in this area every year. The results reveal ground-surface deformations during the study period along the satellite line of sight near to the main road in Balloran dam area with a maximum value reaches to around 20 cm. The D-InSAR results were compared to the D-GPS results of 10 validation points along the main road in the study area, where the RMS difference value was 20 cm.