Análise da evolução do uso e ocupação do solo e das perdas de solo na bacia experimental do riacho Guaraíra.

Abstract

The intensification of agricultural practices and urban sprawl in watersheds has accelerated erosion processes. Before that problematic, this paper aimed at analyzing the evolution of the use and occupation and soil loss in the Guaraíra River Experimental Basin to 1974 and 2012, using remote sensing techniques, GIS software ArcGIS 9.3 and the empirical equations USLE and PNE. The results obtained from temporal analysis of the use and occupation of soils confirmed a predominance of monoculture sugarcane, which holds 34 % of the basin area, while the vegetation lost nearly 30 % of its natural composition. Applying USLE method, soil losses from 1974 and 2012 ranged from 0 to 20 ton/ ha/year, with a predominance of losses less than or equal to 5 ton/ha/year, about 90 % of the basin. Using the method of PNE results showed that the basin has a low erosive potential in 83.7% of the basin. Therefore, the use of empirical equations in integrated GIS proved to be an effective technique in the spatial representation of soil losses and to identify areas most vulnerable to erosion and may provide grants for planning related to the proper management of vegetation and the type of soil in watersheds.