EFFICIENCY OF THE CURVE NUMBER METHOD OF RAINWATER RETENTION

ABSTRACT The present study presents the results of research whose main objective was to use hydrological data on flow to verify the efficiency of the parameter curve number (CN) of rainwater retention in river basins on a regional scale, through multivariate statistical analysis, to contribute to the administration and management of water resources. The CN is part of the method of estimating flow used by the Soil Conservation Service (SCS). This rainfall-runoff model is used to estimate flow in small river basins, based on soil data and the evolution of land use and occupation. The method was applied to 14 hydrographic sub-basins - PR, whose confluences coincide with the gauging stations, to set up the sampling points for the multivariate statistical analysis of canonical correlation. The result of the canonical correlation, represented by the canonical R was equal to 0.90 with canonical R2 equal to 0.81, chi-square (χ2) of 15.8577 and DF (degrees of freedom) equal to 7, which is very significant and expresses a high correlation between the method and flow rates. These results confirm the hypothesis that the CN can be validated by the flow.