Análise do processo de degradação ambiental em Pombal-PB utilizando sensoriamento.

Abstract

In the state of Paraíba, two-thirds of the total area correspond to the Caatinga ecosystem, a fragile and vulnerable biome. An instrument that has been widely used to survey and reconnaissance of areas undergoing desertification is the remote sensing. The objective of this study was to analyze and map the progress of degradation in the city of Pombal-PB through the years of 1985, 1995, 2006 and 2009, by the study of NDVI and Albedo. Four TM – Landsat 5 images were acquired, corresponding to the period of drought at research region: November 18, 1985 (day of the year - DOY 322), September 11, 1995 (DOY 254), September 25, 2006 (DOY 268) and November 3, 2009 (DOY 307). There was a reduction in denser canopy and increasing of bare soil and sparse scrub vegetation, especially in places near the river Piancó. In much of the municipality, the albedo values increased with the years, while the NDVI values decreased, what shows the urban sprawl, the growing of degradation of natural vegetation and increased areas of exposed soil, phenomena inherent to the process of desertification. Thus, it was concluded that the albedo and NDVI indices were effective in assessing the changing surface and the results can be widely applied in actions for preservation and restoration of Caatinga biome in the cimunicipality of Pombal.