Rainfall-runoff process analysis of the Pequeno River catchment, Curitiba metropolitan region, Brazil, with two hydrological models

Abstract

The rainfall-runoff process of the Pequeno River catchment, located in the Curitiba metropolitan region, Paraná State, Brazil was analyzed with two hydrological models, TOPMODEL and HYCYMODEL. Both models were applied to a series of 3360 hourly-observed rainfall-runoff data. The simulations of those models were compared in terms of total runoff generation and hydrograph separation. The uncertainty intervals were estimated for each model using the GLUE method. Both models presented a satisfactory and similar efficiency for the total runoff simulation. The ratio between total runoff and total precipitation was 0.79, 0.81 and 0.74 for the observed data, those calculated with TOPMODEL and with HYCYMODEL, respectively. The models also estimated a large quantity of the baseflow contributing to the total runoff (77.7% with TOPMODEL and 84.5% with HYCYMODEL), but there was a significant difference of those quantities between the models. The surface flow analysis showed that TOPMODEL considered that the catchment saturates and drains faster than HYCYMODEL.