Use of Remote Sensing Data and GIS Technology for Assessment of Landslide Hazards in Susa Valley, Italy

The aim of the research was to monitor and assess landslide hazards by remote sensing data processing and GIS spatial analysis. The automatic classification of remote sensing images pro-vides many useful land use information to combine in a GIS environment with other spatial factors influencing the occurrence of landslide.
The upper part of Susa Valley, in the Italian Western Alps, was chosen as test area because of a large variety of remote sensing data available by ISPRS WG VIII/2 with the aim to exchange infor-mation and experience in the field of geomatic techniques.
It is well known that the occurrence of landslides is controlled by a lot of morphological, geological, and human factors. We have chosen, regarding the available data, the following factors: acclivity, aspect, lithology, land use and precipitations. We have built up a mathematical predictive model enabling ac-tual/potential unstable slopes. It is a linear model where the hazard score depends on instability factors and the coefficients are based on a statistical evaluation. The hazard score is classified into hazard rating to produce a landslide hazard assessment map in GIS environment. This model gives also indi-cations about the relevant factors influencing slope instability. This tool makes the GIS a Spatial Deci-sion Support System (SDSS) for land management.