Proposição de um Método para Estimar Razões Geomorfológicas em Bacias Hidrográficas: Redução de Incertezas por meio da Dispersão dos Parâmetros Morfométricos

The hydrological modeling of small and medium-sized watersheds often depends on the estimation of geomorphological ratios, which are fundamental for parameterizations of models such as the Geomorphological Instantaneous Unit Hydrograph (HUIG). However, traditional estimation methods are based on aggregate means, disregarding the natural dispersion of morphometric data, which can induce significant uncertainties. This study proposes a new method to estimate geomorphological ratios, incorporating data dispersion to regression adjustment, which provides greater physical and statistical representativeness. Fourteen river basins with different physiographic characteristics were analyzed, comparing three estimation methods: simple arithmetic mean (Method 1), regression on means aggregated by order (Method 2) and regression on dispersed data (Method 3). The results demonstrate that Method 3 reduces the uncertainty in the estimates of RL and RA, maintaining statistical robustness, especially in basins with high morphometric variability. It is concluded that the proposed method is more suitable to represent the complexity of the basins and can significantly improve the performance of hydrological models that use geomorphological ratios as input.