Geoprocessamento no estudo da desertificação: município de Prata, PB.

Abstract

The municipality of Prata is located in the Borborema region, in westerner Cariri part of Paraiba State, which has been considered as one of the areas that for more than ten years is being affected by a long and catastrophic disaster, due to a lack of a governamental planning for the land use and due to a low precipitation occurred during the critical periods of drought, many times, influenced by the ENSO phenomena. This research developed in the municipality of Prata, of which area is of 178.77 Km2, aimed the use of the Geoprocessing in the comparative analysis of the desertification processes for five different years: 1996, 1999, 2000, 2003 and 2004, based on Landsat and CBERS images. The degradation/desertification processes were analyzed through the visual interpretation and digital processing of the images, taking in account the climatic factors and field data, that pointed out the deforestation and agriculture activities as the principal factors of the degradation of the land and water resources. The climatic factors, due to a lack of an infrastructure for a living together with the semi-arid, have strong influence on the water resources. However, there is not an environmental education policy for the population in order to qualify it with knowledge for the upkeep and preservation of the springs and superficial drainage; for the protection of the ciliary forest along the rivers and reservoirs, of which removal provokes the silting up and pollution of the water systems, as well as, about the disordered construction of reservoirs in private property. For municipality eight land degradation levels were defined: Very low, Low, Moderated low, Moderate, Moderate serious, Serious, Very serious and small nucleus of desertification, that for the most recent year of the research (2004), occupied an area of 8.3 Km2, equivalent to 4.64% of whole territory. The analysis of the vulnerabilities of the rural population defined the following numbers: social vulnerability – 44%; economic vulnerability – 76%; technologic vulnerability – 76%; drought vulnerability – 78%. In a general, those values indicate a high degree of insecurity for the population, as values above 45% are not acceptable because they point out that the population is living much below the poverty line with quality of life below national average.