Riscos e vulnerabilidades- campo petrolífero Canto do Amaro, Mossoró-RN.

Abstract

The study area, the petroliferous field Canto do Amaro, have an area of approximately 127,37 km2, concentrates more than 1.600 wells of oil exploration, is located in the municipality of Mossoró-RN in the Geographic Micro region of Mossoró, in the most eastern portion of the Northeast Brazil, the Potiguar Basin. The city of Mossoró has an area of 2.108,9 km2, with a population of 213.841 inhabitants The average temperatures is of 33 °C with minimums of 22,5 °C. The relief is characterized by a plain surface with average altitude of 16 meters and the rainfall average is of 600 mm/y. The methodology was based on the comment and description of the conditions of all infrastructures of PETROBRÁS for oil exploration, defining the risks to the environment and local population. Landsat, IKONOS and SPOT images was used for the evaluation of the land degradation. In the area strong marks of the human activity had been observed in the process of land degradation where the natural dynamics has been neglected. In the evaluation of the images three levels land degradation had been defined: Moderate, Serious and Very Serious. The soil exposed are, in general, areas of extracting of material for construction of the bases of the exploration oil structures, roads and other constructions, where works for conservation and recovery do not exist and the erosive processes progress quickly. Although to be an area of agricultural use, with extensive cattle raising, the main land degrading agent has been the petroliferous exploration. On bases of the use of the images of satellite IKONOS the erosion in the edge of the estuary of the Apodi/Mossoró rivers was evaluated. The process of erosion observed in the area, not only involves the questions of the global climatic change and geologic, but it shows to have a direct relation with the activities human beings in the region, as the oil exploration. 7 soils samples had been collected for risks analyze to oil infiltration, for which the values of the DTA had been determined. The DTA of 57% of the soils are above of the average of 1,41 mm/cm showing an loamy sand texture and sandy loam for 43% remains, whose DTA had been minors of 0,86 mm/cm. The test of water/oil infiltration in these soils had shown that the VIB for water is high to very high one for the oil was of low to medium. Questionnaires had been applied to 10% of the families of the community to characterize the socioeconomic and environmental profile of the local population. The region is submitted to the intense anthropic pressure in consequence of the activities of the petroliferous and salt industries and agriculture activities. The analyses of the diagnostic had shown that the social global vulnerability of the population is of 66%, index considered unacceptable, that translates low education, the precarious conditions of housing, low income, water infrastructure deficiency, low ambient perception capacity, land degradation, etc. This vulnerability is caused by the lack of public polices for the environmental sustainable development, that aims the risks reduction, with social inclusion and environmental protection. Among others the research concluded that the petroliferous industry urgently needs to take measures for the risks reduction, therefore the soil with loamy sand and sandy loam texture leave the ground water vulnerable to oil spills, that are not little frequent in the area, as also to be more rigorous in the comment of the norms of protection in petroliferous exploration. With relation to the Apodi/Mossoró estuary the structures must be constructed in order to not unbalance its dynamics.