Applicability of the LASH model for hydrological simulation of the Grande River Basin, Brazil

Abstract

The Lavras Simulation of Hydrology (LASH) hydrological model is classified as a deterministic, semiconceptual, and spatially distributed model. This model was developed to make available a tool for hydrological analysis in watersheds with a limited database, and it has presented good streamflow predictions. The aim of this study was to calibrate and validate the LASH model for hydrological simulation of the following watersheds which make up the headwaters of the Grande River basin (southern Minas Gerais state, Brazil): the Aiuruoca, Grande, Sapucaí, and Verde river basins. The LASH model simulated adequately the hydrological regimes of the previously mentioned watersheds, presenting satisfactory performances for all the watersheds, which can be emphasized by the Nash-Sutclifffe coefficient (CNS) values greater than 0.70. The analysis of the main hydrological processes simulated by the LASH model confirmed that the results were consistent with the hydrological characteristics observed on the respective watersheds. The simulated daily flow-duration curves demonstrated good agreement in relation to the observed curves, indicating only a few errors in estimation of extreme streamflow events. It was found that the LASH model can be applied for hydrological simulation of headwater watersheds situated in the Grande River basin under land-use scenarios and meteorological and environmental conditions other than the ones used in this study. Therefore, it can be considered an important tool for planning and management of water resources in this region.