Emprego de geotecnologias na estimativa do potencial de erosão dos solos do Município de Aparecida - Paraíba.

Abstract

Use of geotechnologies in the estimation of soil erosion potential in the Municipality of Aparecida - Paraíba. The overuse of land in the Brazilian semiarid region represents one of the limiting factors to its socioeconomic development, regarded its contraposition to maintenance of the sustainable and functional diversity of the environment. The environmental risk related to soil erosion in the semiarid region is extremely serious for its environmental system, considering the fragilities expressed by its dominant physiographic characteristics. Studies corresponding to the physical environment of soils in the semiarid region, in particular, the ones related to the determination of the Natural Erosion Potential (NEP) are relevant for the comprehension of their increasing processes of environmental degradation. This research has as a goal to determine the Natural Erosion Potential of the soils in Aparecida-PB, located in the western portion in the State of Paraíba, mesoregion of Paraíba countryside. For the process and analysis of geospatial data, the Geographic Information System IDRISI V. 17.0 was used. Statistical treatment based in linear regression was applied, intending to characterize the simple correlation included among the information plans NEP and the following decisive parameters: erodibility (K), slope length (L) and declivities (S). The estimation of the soil loss tolerance allowed to identify that the unit of Red Yellow Podzolic soil Eutrophic Equivalent presents the greatest tolerance (6,6 t ha-1ano-1), decreasing in order, by Chromic Luvisols units (3,1 t ha-1ano-1), Vertisols (1.5t ha-1ano-1) and Dystrophic Regosol (1,1t ha-1ano-1). The estimation of the Natural Erosion Potential for Aparecida countryside – PB resulted in 14783 hectares specialized in a very high class (>800 t ha-1ano-1), distributed in different declivity classes, representing 65% of the studied area and observing that this spatial distribution prevails in approximately 50% in the declivity classes understood between 2 to 10%. The application of the data statistical treatment, through the linear analysis of regression allowed explaining that the greatest contributions for the definition of the NEP classes, with a higher loss potential are erodibility and slope length. When it is considered, in the statistical operation, the minimum value of the NEP classes, these parameters explain respectively 71,3 and 85,9% the Natural Erosion Potential.