Analysis of Drainage Basin Asymmetry in the Ventena River, Northern Apennines (Central Italy)

Abstract

In this paper a case study of the Ventena river basin in central Italy it is describes here, where the need to understand the relationships between the intensity of erosive processes and basin asymmetry made it necessary to analyse and to compare the asymmetry factor (AF) and the energy of relief (Er). This basin has the characteristic of displaying strong asymmetries that, for some authors, are caused by the different intensity of erosional processes on the opposite sides of the basin due to their orientation. To study in great detail the asymmetry factor (AF) and the relief energy (Er) and their relationship along the entire basin a method of calculating and representing these two geomorphic indices recently tested for this type of analysis was used. The data carried out show that in the Ventena basin there is not any direct relationship between the asymmetries and the intensity of erosive processes on the sides of the basin. The results of this analysis, supported by other investigations such as satellite imagery observations, show that the asymmetries seem to be due to different causes instead to orientation which may have had a marginal role only. In particular the results suggest that the structural control of the main stream might be due to under printing, to the transmission of structures located under the surface into the sequence above.