O geoprocessamento no diagnóstico de vulnerabilidade socioambiental em áreas urbanas: estudo de caso na Bacia do Rio Mané Dendê - Salvador

Abstract

Land-use planning acts as a disciplinarian of anthropic interventions in order to control population growth and avoid the people to settle in areas with natural hazards, especially in large urban centers. The impacts caused by these disasters can be minimized by applying preventive measures such as zoning. It identifies and maps risk areas and populations who are in situation of environmental and social vulnerability. Between 1991 and 2010, floods and landslides were the natural disasters with the most fatalities in Brazil. Aiming to contribute with land-use planning and to reduce the impacts caused by these natural disasters in urban centers, this project proposes a methodology to for spatial identification of social and environmental vulnerability. The method was applied in Mané Dendê River’s basin, at Salvador, Bahia. This study area is characterized by its high population density and great concentration of low income population, with high occurrence of irregular settlements. It has high environmental and cultural value because it is located in the vicinity of Parque São Bartolomeu. This park olds a home for the larger reminiscent Mata Atlântica area in urban zones in Brazil. Also, famous historical independence rebellions happened there, like Sabinada. Nowadays, the park is a sanctuary for secular rituals and it is the greater reference of African-Brazilian cults in the country. It was used geoprocessing techniques to identify the areas and the population that are vulnerable and graphically represent them through the generation of thematic maps. The environmental vulnerability map was generated through identifying the areas with risk of landslide and floods. It was determined a Social Vulnerability Index to each census district through variables of infrastructure (habitation and sanitation), income, education and social status. These variables were developed based on the 2010 census database published by the Brazilian Institute of Geography and Statistics. Then, it was generated the social vulnerability map. The social and environmental vulnerability map was made by applying the map algebra technique, which is largely used for environmental impacts assessment. The social vulnerability method was considered satisfactory once it follows the pattern adopted by similar works, applied in Brazil and around the world. However, it is recommended for future works a deeper analysis of the criteria used to obtain the environmental vulnerability map so that the final result will be able to represent a safer tool for the decision making in the scope of territorial management planning