Lash hydrological model: an analysis focused on spatial discretization

Abstract

Many of the traditionally used hydrological models have complex formulations and require several input variables over time and space, which are generally scarce and expensive for obtaining, especially in developing countries. In order to overcome these limitations, the Lavras Simulation of Hydrology has been developed and successfully applied to Brazilian basins. The most recent advances of the model address the adaptation of the automatic calibration module considering its distributed and semi-distributed schemes and requiring only a few input variables. In view of this improvement, this study had as main objective to evaluate the performance of the model regarding the estimation of daily hydrograph using two spatial discretization schemes of the basin (distributed and semi-distributed). The hydrographs estimated according to both schemes were compared to the observed hydrograph in the Fragata River basin (FRB), located in Southern Brazil, by using statistical measures. The results indicated that there was effect of the spatial discretization on the quantification of hydrological processes in the studied basin. It was concluded that the distributed scheme outperformed the semi-distributed scheme, although the latter has also provided satisfactory results and can be therefore used for hydrological modeling.