APPLICATION OF INSAR TECHNIQUE FOR THE DETECTION OF GROUND DISPLACEMENT IN PENANG ISLAND, MALAYSIA

Abstract

Slope failure is Penang Island's most critical geohazards that inflict significant economic damage each year. Penang landslide is considered one of the most disastrous landslide regions in Malaysia. The threat to lives and property had been associated with the slope instability issues for decades and continuous rain that usually lasts for hours/days. Earlier research employed simulation and modeling to address this hazard, but InSAR technique has not been fully utilized to quantify Penang Island's movements. It now requires proper monitoring using satellite techniques. Sentinel-1A S-1A images acquired enables Synthetic Aperture Radar (SAR) processing technique looks very promising. The data were processed using a versatile and powerful tool called SARPROZ software. The Permanent Scatterer Interferometric SAR (PS-InSAR) technique was applied to monitor ground deformation in Penang Island, Malaysia, as various deformations have been reported for years. The results of S-1A data show slow ground deformation values ranging between -9.19 mm/yr and -10.00 mm/yr for subsidence pattern and from 5.00 mm/yr to 4.66 mm/yr for uplift behavior. The results with S-1A data confirmed a trend of deformations around the regions. This reflects the improvement of the S-1A datasets for the PS-InSAR analysis in the region. InSAR result was validated using available GPS analysis. The results were also related to some works on physical parameters such as rainfall, slope, geology, and soil properties of the region for comparison. However, the detailed spatial pattern of surface displacement in the middle of the island is not clear as persistent scatterer has a limitation in the vegetated and rural areas.