Análise multitemporal do uso e cobertura do solo na sub-bacia hidrográfica do Arroio Arenal, Santa Maria/RS

Abstract

The land use indicates the appropriation of nature by society and the fragility of the environment. In this context, the remote sensing allows through satellite images, follow the transformations of space over time. This work aims to analyze the dynamics of the classes of land use and cover in the hydrographic subbasin of Arroio Arenal-RS, with the classification / processing Landsat-5/TM image through assessments multitemporal. The methodology consisted in the analysis of a distinct temporal series between the years 1995 and 2010, generating representative landscape information enabling the creation of land use and cover maps. The spatial analysis was based on LEGAL language, running on SPRING software, with which were also prepared thematic maps, using the method of classification by maximum verisimilitude (GML). In this process, were generated data that allowed the use and land cover spatial analysis, thereby defining the parameters necessary to evaluate the dynamics of forest and agricultural developments. The main results showed the predominance of grazing in the regional landscape, occupying 36% of the area, the wide dissemination of the crop fields, measured in 17604.017 hectares, and also the reduction of forest areas and regeneration, at 2112.106 and 3093.507 ha respectively. As the mapping of permanent preservation areas were determined environmental conflicts caused by agricultural practices in inappropriate places. Thus, the temporal analysis of a subbasin, using the classification of digital images proved relevant to identify the processes triggered by human action on the environment.