Validación del método de Número de Curva en tres microcuencas aportantes del Río Pisque en Ecuador

The analysis of the hydrological response of watersheds has made the use of the Curve Number methodology relevant. However, the global application of this method has presented limitations mainly associated with the availability of land use and hydrology information for the study areas. The Global Curve Number map (GNC) is a tool that defines the value of the curve number of a region with a low spatial resolution (250 m) and its validation is necessary in the development of research related to water resource management in watersheds with limited information. The present study determined the representative curve number value in three micro-watersheds contributing to the Pisque River in North Ecuador. Curve number values proposed by the GNC for these micro-watersheds were compared with curve number values obtained for land use scenarios for the years 1986 and 2013, generated through the analysis of maps derived from satellite images. The geographic land use and vegetation cover was obtained through principal component analysis and validated using the confusion matrix method and the kappa index. The proposed land cover classification had a high accuracy (82 - 84 %) when compared with secondary reference information, which represents high reliability in the curve number maps generated for the study area. The models developed for the three micro-watersheds present greater detail and spatial resolution, maintaining an excellent fit with the CNG which is reflected in the goodness of fit statistics (NSE = 0.96 - 0.98, PBIAS = 13.06 - 19.03 and RMSE = 18.94 - 22.21).