Modelagem espacial para análise da restrição ambiental para a expansão urbana em Itabira/MG

Abstract

Nowadays, there is a growing need to consider the various factors that influence the process of occupation of space, which are often discarded by permitting laws or through the lack of in-depth studies on the identification of areas restricted to urban expansion. In Brazil, accelerated urban expansion has generated various orders of socioenvironmental conflict and, in order to delve deeper into this issue, this paper aims to propose a method, based on Uncertainty Analysis (UA) and Sensitivity Analysis (SA) , that allows for a multicriteria evaluation of the levels of environmental restriction to urban expansion in the municipality of Itabira, Minas Gerais. The uncertainty and sensitivity analyses aim to assess the robustness of the results from the multicriterial evaluations, which, in turn, makes it possible to identify how much each criterion interfered in the uncertainty of the results. The method was based on the following steps: defining the object of study, selecting variables, treatment, classifying and weighting the variables, using the Delphi method, using the hierarchical weight analysis method (WAM), describing and comparing the advantages and disadvantages of the different methods, multicriteria analysis, the Monte Carlo method, and proposing the model. With the result of the model, it was then possible to identify the levels of environmental restriction to urban expansion in the municipality. Areas with a high restriction level were identified, but with low uncertainty of the result, indicating that urban occupancy in these areas is not of interest. Areas with a high restriction level and high uncertainty in the result were also identified, indicating that in order to better respond to the model in these areas, it would be important to carry out additional investigations and, if necessary, makes changes in the model, such as inserting or changing variables in the analysis. Areas with a low restriction level, but a high uncertainty of the result, are considered considered less restrictive areas. Lastly, areas with low levels of restriction and a uncertainty of the result were identified, meaning that there is no doubt in the result in these areas; thus, these areas can be considered the most suitable for urban expansion, considering the concepts and methods addressed in this study. With that in mind, in addition to the study of public policies that have has been formulated and already implemented, the proposed representation method is a useful tool to assist urban planning and management policies, aimed at preventing and mitigating risk situations and the vulnerability of space in Itabira.