Mapeamento da fragilidade ambiental da Bacia Hidrográfica do Rio do Quilombo – São Carlos/SP

Abstract

This research consisted in the elaboration of the Environmental Fragility map for the Quilombo River Basin, in its parcel located in the municipality of São Carlos / SP, adapting the methodologies proposed by Calijuri (2007) and Cereda Junior (2011), applying the fuzzy nonlinear sigmoidal logic in the standardization of the characteristics of the physical environment of the study area. The non-linear fuzzy sigmoidal standardization showed a higher concentration of results at the extremes of the lowest and highest values, therefore, its application in the mapping of environmental fragility should be performed with caveats, preferably combined with maps algebra models that allow the attribution of weights to the parameters analyzed, according to their importance in the stability of the terrain. The Environmental Fragility map was elaborated through the correlation of the parameters "land use and occupation", "slope", "pedology", "distance of water bodies" and "pedology". The map algebra methods applied in this research were the AHP, Weighted Arithmetic Mean and Simple Arithmetic Mean, the latter used as the comparison value. The results for the AHP model were 6% for "Very Poor", 22% for "Weak", 37% for "Average", 28% for "Strong" and 8% for "Very Strong" respectively. The Weighted Arithmetic Average presented 4% for "Very Poor", 18% for "Weak", 46 for "Average", 29% for "Strong" and 3% for "Very Strong". The methodology for mapping the environmental fragility proposed in this study prioritized the parameter soil use and occupation, bringing as a positive result the possibility of updating the values of environmental fragility according to changes in soil cover. In relation to the Municipal Master Plan, the guidelines for land use and occupation are in line with the natural characteristics of the study area, mainly in the conditioning of urban expansion with the adequacy of road infrastructure and urban drainage, as well as the preservation and recovery of native vegetation and areas of permanent preservation.