RELATIONS BETWEEN MORPHOMETRIC CHARACTERISTICS AND DENUDATIONAL PROCESSES IN SOME DRAINAGE BASINS OF ITALY

The possible relations between morphometric characters of drainage basins and the type and intensity of denudational processes were investigated. Data obtained for several different areas of central Italy and for three sample basins in particular, suggest that the degree of organization of drainage nets, expressed by the "density of hierarchical anomaly (ga)", is strictly tied up to the type and intensity of denudational processes. In particular, the more effective the slope processes are the higher are the values of ga; the maximum values are reached in badlands, while the lowest values occur where fluvial deepening is more effective than slope processes. Moreover, the area-altitude analysis revealed that in the areas examined some relations exist between the hypsometric curve trends and the type and intensity of denudational processes. Convex curves with high integral are usually typical of basins in which stream erosion is the most vigorous among denudational processes. Upward concave curves with a low integral mark basins mainly affected by intensive slope processes, badland erosion being prevalent. Finally, hypsometric curves with integral close to 0.5 are characteristic of basins where stream erosion balances the effectiveness of slope processes. An interpretation of the area-altitude analysis results is then delineated which adds efficaciously to the traditional one; in this interpretation the hypsometric curve not only express the stage of the "geomorphic cycle" but also the rate of the geomorphological changes that take place in drainage basins.