From hazard monitoring to risk assessment by monitoring both ground deformation and human structures stability (e.g. dams, specific buildings etc) is of great importance contributing to prevention and management of these risks. An analysis of the ground deformation in the area of Rio-Antirio (western Greece), where the longest cable stayed bridge in the world, was performed using ERS-1/2 SAR data. In this study preliminary results are presented for the pre-construction period. An interferometric point target analysis was performed with images covering the period between 1992 and 2000.