Análise multitemporal do uso da terra e cobertura florestal com dados dos satélites LANDSAT e ALOS

Abstract

The monitoring of the use and coverage is very important when studying determined regions, just because it helps knowing the environmental reality and contributes to solve problems that can probably appear. This research was done from the images of ALOS and LANDSAT satellites. Its main objective was to have a multi-temporal analysis of Arroio Grande micro watershed, central region of Rio Grande do Sul. The specific purposes were to identify and to quantify the different classes of land use found in this micro watershed along the 1987, 1998, 2002, 2005, 2007 and 2009 periods, as well as cross the land use information to show the forest coverage changes during the 22 years of analysis. The software SPRING 5.1.7 was employed to classify the supervised images through Bhattacharya, a sorter algorithm, and the map spatial analysis was done through the Spatial Language of Algebraic Geoprocessing program with the same computational application. The classes of land use as forest, field, agriculture, irrigated agriculture, exposed soil and water layer were observed in the images of each year in this analysis. These classes were utilized in the spatial analysis of the forest coverage in which forest monitoring parameters have been defined (forest maintenance and regeneration, deforestation). In this research the principal results that have been noticed were the increase of 17,98% on the distributed forest coverage, mainly in the areas of bigger declination, and the reduction of 16,32% on the field area. The analysis of the spatial forest coverage has presented stability with the landscape, in a gradual progression, because the area of forest maintenance, found in these 22 years, was 12.252,60ha, the forest regeneration was 4.389,12ha and only 1.853,82ha of deforested area.