Development of a data base of land characteristics and computerized analysis of actual and potential land degradation risks

In this paper the development of a data base of land characteristics is described; both graphic and numeric data are memorized for the vealuation of land degradation risk. In particular, the algorithms are described for the automatic overlay of thematic maps and for the synthesis of the results. Geographic data are stored and processed in vector form to achieve maximum output precision, although computer processing times are fairly long. The thematic maps involved in the application are: hydrography map, contour lines map, land-use map, soil map, geology and landslides map. Both cartographic and tabular output is described and the algorithms for the automatic evaluation of the rainfall erosivity index are also described.