Detection of past slope activity in a desert area using multi-temporal DInSAR with Alos Palsar data

Abstract

Coastal slope involved in the construction of a road in the Sultanate of Oman was affected during the period 2011-2012 by instability processes. Lithological and geomorphological evidence suggested a general conformation of the slope that is very prone to gravitational instability processes. Because satellite SAR interferometry (InSAR) is the only technique that is able to provide quantitative information about past ground displacements, it has been chosen to investigate the past evolution of the slope. Nine archived SAR images acquired by the ALOS PALSAR have been analysed using a hybrid approach based on the classical differential interferometry (DInSAR) and Quasi-Persistent Scatterers (QPS) techniques. Some ground deformation processes have been detected and measured on three portions of the slope. One of them has been localised within the area affected by the recent landslide phenomenon. Thanks to this approach the deformation processes have been defined in time and the related displacements have been quantitatively estimated.