TOWARDS A DEFINITION OF TOPOGRAPHIC DIVISIONS FOR ITALY

The study has divided Italy into eight major topographic divisions (pr ovinces) and 30 minor divisions (sections) that are similar to N. Fenn eman's units of the United States. Provinces and sections are generall y consistent with observed morphology. The new units were defined step -wise in a semi-quantitative approach that combined an unsupervised th ree-class cluster analysis of four derivatives of altitude, visual int erpretation of morphometric maps (including shaded relief), and compar ative inspection of small-scale geological and structural maps. The fo ur variables are altitude, slope curvature, frequency of slope reversa l, and elevation-relief ratio. Highland, upland, and lowland topograph ic types were identified. The variables were computed from a 230 m res olution digital terrain model, regridded from the original 230 m DEM o btained by mosaicking the entire Italian mean elevation archive.