Landslides detection in Bat Xat district, Lao Cai province, Vietnam using the Alos PalSAR time-series imagery by the SBAS method

Abstract

Radar Interferometry (InSAR) has been known as a technology to monitor the change of elements on the earth's surface for many years. There are many InSAR methods, in which the permanent scattering InSAR Radar (PSInSAR) method uses a series of images to determine the terrain deformetions quite well. However, for areas with lots of vegetation, the number of permanent scattering points (PS points) will be limited. In this paper, we have chosen a method that also uses a set of multi-temporal Radar images but has the lowest spatial and temporal image baselines, this method is called the Small Baselines method (SBAS). With the ALOS PalSAR images series that was collected from August 2007 to November 2010, many landslide points in the area of Bat Xat district, Lao Cai province were discovered. The landslide locations detected from Radar images were compared with the landslide surveying points and landslide interpreted by aerial photos in 2013 provided by Vietnam Institute of Geosciences and Mineral Resources Vietnam. There have been many sliding sites coinsiding with the surveyed landslides, which proves that many landslides exist and develop continuously such as the location of Mong Sen bridge, Trung Chai Commune or at Sai Duan bridge, Phin Ngan commune.