Stima della portata indice: legame tra il coefficiente d’afflusso e la caratterizzazione dei suoli secondo il SCS

In the evaluation of flood peak discharge of a generic catchment it is of fundamental importance to determine its runoff coefficient. To this aim, unfortunately, bibliography gives a lot of qualitative considerations but scarce quantitative supports. The U.S. Soil Conservation Service (SCS) has characterized the hydrologic soil-cover complexes with the runoff curve number (CN) and has defined its value, in the range between 0 and 100, as a function of the soil type and land use, the soil cover complex and condition, and the antecedent soil moisture (AMC). In the present paper a relation between curve number and runoff coefficient has been proposed for flood index assessment. Moreover a hydrologic soil-cover complex map of Campania Region has been supplied to evaluate the average runoff curve number for any catchment within the region.