Integration of multispectral data acquired by aerial and satellite platforms for the study of the phenomena caused by the November 1994 flood in Piedmont (Italy)

The aim of the present work is to develop a new methodology suitable for landslide and flooded area extraction assessment using remotely sensed data acquired by satellite platform. This study was conducted after the still famous flood event that occurred in Piedmont (Italy) during November 1994. Caused by the heavy precipitation and by slope instability (due both to natural and artificial causes) in the southern part of Piedmont (and in particular in the Langhe area), an impressive series of catastrophic events occurred with the flooding of almost all of the area rivers and a rather large number of landslides in correspondence to the most hazardous slopes. During those days and in the following, several multispectral images were acquired by both airborne and satellite platform; these images are, still now, a not totally exploited source of data, suitable for the analysis of the territorial effects of such tremendous catastrophic phenomena. Particular attention has been paid to the setting up of a methodology suitable to establish the relationships between landslide (essentially debris flows), flooded areas and radiance and emittance data coming from the earth surface and recorded by the sensors mounted on board artificial satellites. All the data have been georeferenced, pre-processed, filtered and the images classified in order to evaluate from training samples a typical debris flow and water spectral signature.