Modelagem do escoamento e erosão sob diferentes condições de chuva e uso do solo em bacias do cariri paraibano com o modelo distribuído MOSEE.

Abstract

The growing demands for water resources and the climatic changes and human activities have been affecting a great deal the runoff and soil erosion processes, which require quantification and evaluation. In this sense, representative and experimental basins have been instrumented everywhere for data acquisition, and analysis of these processes. In the state o f Paraiba, from the 80s on, several initiatives have been taken to acquire data in experimental and representative catchments, and model relevant hydrologic and erosion processes using, principally, event-oriented models, which have been given evidence of their importance to represent the processes at an event basis. However, to evaluate the effect of climatic and land use changes on basin responses it is necessary to use appropriate models such as physically based continuous models. In this research the continuous physically based model MOSEE, a model for soil erosion estimation, was applied to micro-basins in the representative basins of Sume (RBS) and its sub-basins, to micro-basins in the experimental basin of Sao Joao do Cariri (BESJC) and its sub-basins, to simulate runoff and soil erosion using observed data of natural rainfall considering different proportions of deforestation and afforestation. The model results agreed quite well with the observed values, and the effects of deforestation on responses were relevant, mainly on the soil erosion due to the increasing soil detachment and runoff and sediment transport, while the afforestation had great impact in reducing runoff and soil erosion. The model results also demonstrated to be very sensitive to the rainfall variability.