Integration of remote sensing techniques for the evaluation of the landslide hazard
Abstract
Slope movements are worldwide recognized as the most damaging natural hazard, even though sometimes their effects are erroneously attributed to other hazards such as earthquakes, floods, tsunamis, etc.: they affect wide areas, producing severe economic damage, as well as direct and indirect losses, in function of both landslide velocity and exposure of the main elements at risk. Evaluation of the landslide hazard is therefore of extreme importance, in order to address the future development of built-up areas toward territories not affected by slope movements. Remote sensing techniques, that is the observation and analysis of the earth landscape from a distance, have being used since many decades at this aim. In the last 20 years, the use of satellite images considerably increased the role of remote sensing techniques, opening the ground to many new, technologically-advanced, applications. In this paper we present the results obtained by integrating different remote sensing techniques for the evaluation of the hazard related to slow-moving, intermittent landslides in the Southern Apennines of Italy. The work has been carried out by means of multi-temporal analysis of aerial photographs, that allowed to assess the spatial and temporal evolution of slope movements in a 50-years time span. Landslide inventory maps, produced for each pair of available aerial photos, have been compared to obtain landslide activity maps, that represent a shortcut for assessing the evolution of slope movements, since they focus on the effects of slope instabilities rather than on the causative conditions and processes. In these maps, the landslide activity trends are based on the variations in areal frequency of mass movements in time; thus, the estimates of these variations need not reflect the exact absolute values of landsliding. The stereoscopic observation and interpretation of vertical aerial photographs have been then integrated by analysis of satellite images (years 1992-2001) through the tool of space-borne SAR interferometry. In particular, the Differential InSAR (DInSAR) analysis has been considered, and the Permanent Scatterers (PS) technique applied. Advantages and drawbacks of this integrated approach are eventually discussed, to highlight the need of further research in order to let DInSAR techniques become a full operative tool for geoscientists and land planners.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2009
- Bibcode:
- 2009AGUFMNH43C1331C
- Keywords:
-
- 0933 EXPLORATION GEOPHYSICS / Remote sensing