NEW METHODOLOGIES FOR THE INTEGRATION OF MULTISPECTRAL DATA ACQUIRED FROM AERIAL AND 
SATELLITE PLATFORMS: THE NOVEMBER 1994 FLOOD IN PIEDMONT (ITALY) CASE STUDY 
P. Boccardo, G. Comoglio - Politecnico di Torino - ITALY 
Commission VII, Working Group 1 
KEY WORDS: Land Slides, Change Detection, Recognition, DEM/DTM, Feature, Extraction, Image, Classification 
ABSTRACT 
The aim of the present work is to develop a new methodology that is suitable for landslide and flooded area extraction 
assessment using remotely sensed data acquired from satellite platform. This study has been conducted after the 
famous flood event that occurred in Piedmont (Italy) during November 1994, which was 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 rivers of the area and a rather large number of landslides occurred in correspondence the most hazardous slopes. 
Particular attention has been paid to the setting up of a methodology that is suitable to establish the relationships 
between landslides (essentially debris flows and slides), flooded areas and the reflectance data obtained from the earth 
surface and recorded by the sensors mounted onboard artificial satellites and aerial platforms. 
In this work, all the data have been georeferenced, pre-processed and filtered and the images have been classified in 
order to evaluate a typical landslide and water spectral signature from training samples. 
The creation of these cartographic features (Landslide and flooded area themes) however involves, the possession of a 
methodological tool that is capable of allowing the passage from the radiometric data to the information content, which 
offers an opportunity of interpreting the image with the consequent creation of relationships between the image 
structure and the elements of the corresponding real scene. 
RÉSUMÉ 
Le but de ce travail est le développement d'une nouvelle méthodologie utile pour l'extraction des zones avec 
éboulements ou esondations avec l'utilisation des données acquises par la télédetection avec plate-formes satellitaire. 
Cette étude a été conduite depuis l'événement alluvionnaire qui s'est produit en Piémont (Italie) en Novembre 1994. A 
cause d'une insistante précipitation et d'une instabilité des versants (due à des causes naturelles et artificielles) dans le 
Piémont méridional (et en particulier dans la région des Langhe) une impressionante série d'événements 
catastrophiques s'est produite avec l'esondation de presque tous les fleuves et un grand nombre des éboulements en 
correspondence des versants les plus au risque. 
Une particuliére attention a été placée pour le développement d'une méthodologie capable d'établir les relations entre 
les éboulements (essentiellement debris flows et slides), les zone esondées et les données de refléctance dépagées de 
la surface terrestre et enregistrées par les senseurs montés sur les satellites artificiels et les plate-formes aériennes. 
Dans ce travail, toutes les données ont été géoréférencées, pre-traitées, filtrées et les images ont été classifiées pour 
évaluer dans la zone étudiée, la signature spectrale. 
La création de ces thématismes cartographiques (zone des éboulements et des esondations) comprend de toute facon 
la possession d'un ensemble d'instruments méthodologiques capables de permettre le passage des données 
radiométrique aux informations contenues, qui permet l'interprétation des images avec la conséquente création de 
relations entre la structure des images et les éléments de la correspondante scéne réelle. 
1. INTRODUCTION environmental data in real-time. Remotely sensed data 
present advantages such as: 
During the flood event that occurred in November 1994 in e multispectral acquisitions, that permit one to 
the north-western part of Italy, several multispectral overcome the electromagnetic spectrum limitation 
images were acquired from both airborne and satellite that is due to the sensibility of human eye; 
platforms. Thematic Mapper multispectral data, Spot-2 e multitemporal acquisition over the same area 
panchromatic, ERS-1 radar and panchromatic thanks to satellite eliosynchronous orbits, that permit 
photogrammetric coverages were acquired in particular. one, to collect data at the same local time with 
These images, which have not yet been totally exploited respect to the latitude; 
to obtain information, are suitable for the analysis of the — e fast data availability, that is no usually longer than a 
territorial effects of such tremendous catastrophic few days; 
phenomena. e relative low cost of data unit; 
The present study has been conducted paying particular  , availability of digital data that allow digital 
attention to flooded areas extraction and landslide processing using standard PCs, without any loss of 
morphologic characterisation, thanks to the development information. 
of the remote sensing techniques that allow one to collect 
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International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B7. Vienna 1996