RELAÇÃO ENTRE O RELEVO E AS CLASSES TEXTURAIS DO SOLO NA MICROBACIA HIDROGRÁFICA DE VACA BRAVA, PB.

Abstract

The disorderly occupation and intensive use of soil in the Paraíba State semi arid land, has resulted in an elevation in the levels of degradation of the environment, as much for the loss biodiversity as for increase in soil erosion. To evaluate the intensity of these processes, a watershed in Vaca Brava was chosen, presenting a strong contrast between a high, protected Atlantic forest area and another under intensive agriculture and stock raising exploration. In the latter, the demographic population is 755 inhabitants per 794 hectares. Initially, a three dimensional survey of the watershed was realized and after divided into themes in relation to the slopes, and in addition, establishing relationships of soil texture and density. According to the obtained results, the topography influenced the texture of soils, since; the amount of samples on the slopes rose, having finer textures, in comparison with footslopes and meadows, where texture thickness predominated, in function of the redistribution of sediments by erosion. The soil density, as was expected, decreasing with the increase of the silt and clay content. In the meadows, footslopes, backslopes and shoulder positions, the use of the soil, seems to have been defined conforming to the variation of texture. In these cases, soils of thicker texture were chosen for agriculture and tall grasslands while the pastures predominated having finer texture.

Keywords

• soil texture
• soil density
• soil used and Geographical Information Systems.