Modelagem do escoamento superficial e da erosão do solo em microbacias.

Abstract

In order to model the run off - erasion process in the Experimental Basin of Sumé, Located in the semi -arid region of the nort heast of Brazil, two different models were tested in four micro - basins having natural vegetation or cleared bare . The first one, MODIBI, is a deterministic conceptual rainfall - runoff model for one day i ntervals and has the input of precipitation and evapotranspiration. The water balance is carried out with a system reservoirs. The second model, WESP, simulates the surface runoff and the sediment production and is based on the processes of infiltration, the hydraulics of surface and channel flow as well as theme chanics of sediment transport. The model uses distributed parameters and simulate seach event separately. The results show that the a greement between the simulated and observed values is satisfactory and a reconsisten twith the earlier studies in the micro - basins regarding its hydrologic characteristics. The erosion parameters estimated during simulation with WESP show a certain level of dispersion but is considered quite reasonable. The modei tested may be considered promissing for the runoff and erosion studies.