IMPLICAÇÕES DAS ALTERAÇÕES NO USO E OCUPAÇÃO DO SOLO NAS PERDAS DE SOLO DA BACIA DO RIO DE ONDAS, ESTADO DA BAHIA

Abstract

The beginning of occupation in the Western region of Bahia for agricultural purposes occurred in the late 1970, which resulted in an intense degradation of the native Cerrado vegetation that existed there. Among the basins that have undergone this intense process of alteration in their use and occupation of land, the Rio de Ondas Basin stands out, which is one of the main sub-basins of Rio Grande, which in turn is the last major tributary of the left bank of the São Francisco River. In view of this problem, the present study aims to analyze the implications of changes in the use and occupation of soil in the Rio de Ondas Basin in sediment yield. For this purpose, USLE was used in a GIS environment and soil losses were analyzed for the 1975 and 2015 scenarios. In which it was found that the Rio de Ondas Basin has undergone an intense change in its use and land occupation in the last 40 years , with the suppression of about 47% of the area of native vegetation, which significantly influenced the increase in the sediment yield in the basin, with topographic factors (LS) and land use and occupation (C) as the most influential factors. The soil losses in the Rio de Ondas Basin were considered moderate, for the current conditions of use and occupation of the soil, but they can be intensified with the increase of the substitution of the native vegetation for agricultural areas.