Estudo dos impactos do uso do solo através da modelagem da geração do escoamento superficial e erosão do solo na região do cariri paraibano.

Abstract

The need to quantify the superficial drainage and the erosion of the soil in the water sub-basins is evident in the planning processes and use of natural resources. The representative basins and you try they form a fundamental paper in the understanding of the behavior of the typical basins of an area. Researches with simulation models developed in representative basins they are means so that your results can, a priori, to be extended for the areas of the which these basins are representative. However, it is known that the scale of the water basin can affect the results and the parameters of a model gauged in a basin it cannot be applied in basins of very larger or smaller size without before evaluating the scale effect on these parameters. For this end, a runoff-erosion model was used, distributed and guided to event, called WEPP (Water Erosion Prediction Project) for application in the experimental basins of Sume and of Sao Joao of Cariri. The application of the model was made in four portions of erosion of 100 m2 , being two in Sao Joao of Cariri and two in Sume, and Sao Joao of Cariri three microbasins and two microbasins of area Sume varying from 0,16 to 1,63 there is, being all, equipped to measure the superficial drainage and the erosion of the soil in the natural events of the rain. The microbasin and the portions were deforested. The results show that the main parameters of the model WEPP, parameter conductivity executes (Ke) of the equation of infiltration of Green and Ampt, relative parameter to the erosion for impact of the rain drops, parameter (Ki) and the erosion parameter in the channels (Kr) they suffer scale effect. A verification of this was made in level of the sub-basins of BRS, and there was the confirmation of the nature of the scale effect. The dissertation presents the details of the experimental units, of the model WEPP and the discussion of results.