Avaliação por geoprocessamento de áreas de criticidade ambiental à ocupação humana na área de proteção ambiental do Catolé e Fernão Velho - Alagoas - Brasil

Abstract

Predatory exploitation of natural resources has been a growing concern on the part of researchers and society practically all over the world. In Brazil, a disorderly occupation of urban spaces has caused several damages to conservation units, especially those located in densely occupied areas, mainly as located in large urban centers. This study deals with the environmental assessment by geoprocessing areas of environmental criticism and human occupation in the APA of Catolé and Fernão Velho, located at these cities: Maceió, Coqueiro Seco, Santa Luzia do Norte, Satuba and Rio Largo in the state of Alagoas - Brazil. An a extreme important area for Maceió´s water supply, responding for 32% of the water supply for population use. In recent years suffering from the unrestrained advance of houses that occupy the limits of that area, in addition to having an important reserve of remnants of the Atlantic Forest. For this study, geoprocessing techniques applied on a geocoded basis of environmental data were used. A geoprocessing assessment was carried out using the QGIS program. Initially, the Environmental Vulnerability Maps for landslides / landslides and floods / floods were generated, as a result of the exposure of pre-existing thematic maps (lithology, geomorphology, pedology, hypsometry, clinography, rainfall and land use and vegetation cover). Then, the Population Density Level Map (inhabitant per hectare) was created, based on the 2010 census sectors of IBGE. The areas of environmental criticality to human occupation, environmental criticality to soil use and vegetation cover, given the population density in areas of environmental vulnerability to landslides / landslides and floods / floods were mapped by the overlapping of the Population Density Level Map, with the Maps of Environmental Vulnerabilities to Landslides / Landslides and Floods / Floods. The overlap of these maps allowed to quantify until then that 64.54% of the APA exhibit médium to high environmental vulnerability of landslides / landslides, while 57.06% medium and high environmental vulnerabilities to floods / floods. These maps are in the final reading, analysis and interpretation phase, based on signatures and environmental planimetry, expected in May 2020 and started with fieldwork for photographic recording. Initially, there are two types of environmental vulnerabilities studied (landslides / landslides and floods / floods), relating, the population density levels with the areas of environmental criticism on the human population in the APA, depends on its natural characteristics, specially, especially the rains intensity , which can be associated with their greater or lesser occupation in the functions of environmental vulnerabilities. In this sense, APA's ecological offer conditions has been clearly hampered by its disordered urban growth, due to environmental management problems, mainly related to the urban expansion of the urban areas of Maceió and Satuba.