Modelagem de processos erosivos hídricos lineares no município de Mineiros - GO

• Ano de defesa: 2015
• Autor(a) principal: Nunes, Elizon Dias
• Orientador(a): Castro, Selma Simões de
• Banca de defesa: Castro, Selma Simões de
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Goiás
• Programa de Pós-Graduação: Programa de Pós-graduação em Geografia (IESA)
• Departamento: Instituto de Estudos Socioambientais - IESA (RG)
• País: Brasil
• Palavras-chave em Português: Compartimentação morfopedológica; Cobertura e uso do solo; Sistemas geomorfológicos; Modelagem de processos erosivos
• Palavras-chave em Inglês: Morphopedological partitioning; Soil cover and use; Geomorphological systems; Modeling of erosive processes
• Área do conhecimento CNPq: GEOGRAFIA REGIONAL::ANALISE REGIONAL
• Link de acesso: http://repositorio.bc.ufg.br/tede/handle/tede/6039

This thesis deals with the constraints of linear water erosion in the municipality of Mineiros- GO, taken as causal explanatory model variables. It is emphasized in soils of high susceptibility which underwent extensive and indiscriminate deforestation along the 1970s and especially 1980, followed by the use of pastures; today they present extensive areas with exposed soil. To develop the model it was sought to correlate the linear erosion focuses, their concentration and contribution area in 2012 with the morphopedological compartments (CMP) and associated pedological systems (SP), in order to identify the most susceptible and in them the most critical segments of studies concerning the risk of occurrence of the phenomenon. The methodology is based on multi-scale integrated analysis of the landscape, initially valuing the scale of 1: 100,000 for the morphopedological partitioning followed by progressively larger scales, that is, detailed to assess the superficial runoff based on the modified rational method adapted from estimated distribution of the flow in the sub-basins associated with the variation of the altimetry amplitude interclass along the studies, the survey and morphology of representative pedological partitions where it was detected a higher magnitude of the erosive phenomenon. It were located and mapped approximately 5678 linear erosion focuses, wherein the concentration can reach 2,46 focuses every Km2, sometimes resulting in environments with up to 36% of the area totally compromised. Among the seven CMP set out , it was stood out (i) the North CPM formed by sandstones and siltstones with the predominance of red-yellowish Oxisol with medium texture and slopes ranging from 5 to 8% that concentrates 33.35% of the outbreaks, and the red Paleudult succeeded by Fluvisol, both with medium texture; (ii) the west CMP formed by windy slope of sandstone ranging from 3-5% where it concentrates 19.60% of the focuses, therefore, comparatively with low incidence of erosion, marked by the presence of pedological systems consisting of red and red-yellowish Oxisols followed by Quartzipsamments in long convex slopes with concave ending; (iii) the Southeast CMP also supported by windy slope of sandstone and it has the predominance of Quartzipsamment with sandy texture where it concentrates 37.81% of outbreaks, shorter slopes, greater dissection of the soil due to the further deepening of the draining channels. The removal of vegetation cover when it reaches fragile pedological systems as the first two, leads to the generation and accelerated evolution of erosion focuses, particularly in drainage headwaters and the middle and lower segments of slopes where the kinetic energy tends to increase exponentially because of spatial and temporal allegiance of surface and groundwater flows. The dynamics of these systems is confirmed and better understood through the analysis of morphometric, morphographic, pedological variables and soil use, resulting in a model that allows representation of critical segments along the slope. The model proved to be efficient to represent the spatial and temporal allegiance of the superficial runoff, thus confirming the concept of power distribution in a system and how this manifests itself in the execution of morphogenetic work. The methodology adopted to associate the morphopedological partitioning and their respective pedological systems in order to develop a four-dimensional linear erosion model was also efficient for allowing the integration of factors, which the resulting intensity converges to the emergence and evolution of erosive processes and can serve as an indicator of risk areas to the phenomenon of installation.