Space‐borne and ground‐based SAR interferometry as tools for landslide hazard management in civil protection

Abstract

In recent years, SAR interferometry has become one of the most popular emerging techniques for the assessment of ground displacements, and, as such, it is of great interest as a possible operational tool for civil protection institutions having to deal with landslide risk. The paper presents some of the results obtained in northern Italy during a research project aimed at testing the potentiality of the application of C‐band space‐borne interferometry and Ku‐band ground based interferometry during different specific civil protection activities. Main research objectives were the detection of the movements of complex earth and rock slides affecting built‐up areas during the 1990s, and the near real‐time monitoring of a reactivated rotational earth slide over an emergency period of 15 days. Results of space‐borne interferometry did qualitatively fit with the geological interpretation of the mass movements and with ground truths such as damaged buildings and in situ monitoring systems. However, this was not achieved in quantitative terms, suggesting that this technique should be used limitedly for displacement recognition and not monitoring. On the other hand, ground‐based interferometry proved valuable both for a qualitative and a quantitative estimate of slope movements. Nonetheless, the research has also enabled the limitations that are still to be tackled in order to bring these systems to an operational usage in civil protection to be highlighted.

Acknowledgments

The research is part of the activities of CNR‐GNDCI (National Research Council's Group for Hydrogeological Catastrophes Defence) Operative Unit no. 2.9 (leader Professor M. Pellegrini) and Operative Unit no. 2.14 (leader Professor P. Canuti). The research was financed by the Civil Protection Service of Emilia Romagna Region under contract ‘SAR‐RER: Monitoring inhabited centres at high landslide risk in the Emilia‐Romagna Region’ (reference persons: Ing. D. Egidi, Dott. S. Vannini, Dott. A. Monni).

Distinct contribution of authors: A. Corsini and P. Farina have co‐written the paper and overviewed the research together with N. Casagli. Researchers from OGS Trieste have carried out processing of space‐borne ERS data. Researchers from University of Modena and Reggio Emilia have taken care of GIS integration of space‐borne interferometric data and provided the geological background for all the test sites. Researchers from the University of Florence and JRC Ispra have run the ground‐based interferometer and processed the resulting data.