Mapeamento geomorfológico e análise do uso e cobertura da terra em áreas do maciço de Água Branca e seu entorno

Abstract

With the advent of geotechnologies, geomorphological-based mapping has become more effective. The new techniques of geoprocessing and remote sensing, aided by the imaging of satellites and other Geographic Information Systems (GIS), provided the improvement, both for geomorphological studies, as for the planning and management of the territory. Due to the landscape diversity present in the Água Branca Massif, involving climate, lithology, soils and vegetation, the study of surface processes based on these conditions becomes extremely important for the planning and management of environmental scenarios. Given the above, the research has as main objective to map and characterize the geomorphological features of the Massif de Água Branca and its surroundings, semiarid of Alagoas. In order to obtain necessary information that serve as requirements to assist in environmental planning and in the management policies of land use. The IBGE methodology (2009) was used as a basis for characterizing the units, using geoprocessing techniques, acquiring SRTM data, analyzing cartographic documents and interpreting orbital images, for the organization of the database referring to the area of study. The land use and occupation maps were made from the LANDSAT-8 images, with the aid of the Quantum Gis software, using the NDVI calculation application. As a result, seven geomorphological units were characterized in the study area: conserved summit; Dissected slope; Conserved hillside; Dissected pieces; Inselbergues; Alluvial planes; Dissected hills. For the land use and land cover maps, the following classes were established: urban area / water resources, pastures, exposed soil, small agriculture, semi-dense vegetation and dense vegetation. Finally, it is concluded that geomorphological mapping proved to be an important analysis and identification tool for the geomorphological facts that occur in the structural massif of Água Branca and its surroundings. The use of geoprocessing techniques with the application of morphometric parameters, were essential in the individualization and description of the geomorphological units. From the mapping of land use and coverage, it was possible to identify a decrease in vegetation cover over the years and an increase in areas for small agriculture and pasture planting, as well as, it was noted that the study area comprising the Massif is considerably little urbanized. Based on the above, it is expected that the information contained in this work, of an exploratory nature, will contribute to the planning of public policies in the municipality of Água Branca, as well as to the development of other studies that focus on understanding the evolution of the geomorphological landscape in the context of Brejo de Altitude and areas controlled by semiarid processes, as well as the natural limitations of these areas for the advancement of different forms of land use, historically marked by the exhaustive process of degradation of the vegetal cover of the soil.