A 51-year dataset from nine meteorological stations in the capitals of northeastern Brazil (NEB), with daily data of precipitation totals and of mean, minimum, and maximum temperatures, was statistically analyzed for data homogeneity and for signals of climate variability. The hypothesis was explored that a connection exists between inhomogeneities of the time series and the meteorological systems influencing the region. Results of the homogeneity analysis depend on the selected test variable, the test algorithm, and the chosen significance level; all more or less subjective choices. Most of the temperature series was classified as "suspect," while most of the precipitation series was categorized as "useful." Displaying and visually checking the time series demonstrates the power of expertise and may allow for a deeper data analysis. Consistent changes in the seasonality of temperature and precipitation emerge over NEB despite manifold breaks in the temperature series. Both series appear to be coupled. The intra-annual temperature and precipitation ranges have increased, along with an intensified seasonal cycle. Temperature mainly increased during DJF, MAM, and SON, with decreases in JJA being related to wetter conditions and more frequent heavy precipitation events. Drought conditions mostly increased in SON and DJF, depending on the timing of the local dry season.

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This paper outlines procedures to analyze the desertification processes in the semi-arid Seridó Region (NE Brazil). Using the Geosystem theory, the detection of desertification areas was based on environmental indices, digital image processing in multispectral analysis and Geographic Information System (GIS). The first step was to treat the rainfall data and NDVI satellite Modis, aiming at identifying areas which do not present vegetation cover, even during the rainy seasons. The second step was to work on a regional scale using Landsat ETM + images (2000)(2001)(2002)(2003)(2004)(2005) and data collected in the field, as the evaluations of exposed surfaces, that together with MDT/SRTM-NASA and thematic maps, allowed to classify the altitude and slope of the relief, soils type, different morphologies and geology, and correlate them with the areas susceptible to desertification process. The integration of the georeferenced data, related to these indicators, allowed the identification of five different levels of susceptibility to desertification (very high, high, moderate, low and very low), and the geographic domain of each class. Based on the analysis of the dynamics of the vegetation cover, we can establish that the main results refer that there is a decrease of the biomass at the region, associated with the dense caatinga vegetation areas, but more important, with the scrub and degraded areas.

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The contamination of water bodies by heavy metals and ionizing radiation is a critical environmental issue, which can affect water quality and, thus, human health. This study aimed to evaluate the water quality of the Boqueirão de Parelhas Dam in the Brazilian semiarid region. A 1-year study (2013-2014) was performed through the assessment of physicochemical parameters, heavy metal content, and radioactivity along with the mutagenicity potential of water using micronuclei test in Orechromis niloticus (in vivo) and the cytokinesis-block micronucleus (CBMN) assay in human lymphocytes (in vitro). A deterioration of water organoleptics characteristics by the presence of high levels of sulfate and total solids was observed. High concentrations of aluminum, nickel, silver, and lead along with the alpha particle content were higher than the limits suggested by the World Health Organization and Brazilian legislation for drinking water. An increase in the frequency of micronuclei and nuclear abnormalities was observed in both experimental models. The results obtained confirmed the mutagenic potential present in water samples. This study highlights that geogenic agents affect water quality becoming a human health concern to be taken into account due to the relevance that this water reservoir has in the region.

The petrography and chemistry of epidote and amphibole from the Rio Espinharas hybrid complex (REHC), northeastern Brazil are reported. The Rio Espinharas complex is composed of an intimate association of diorite to shoshonitic metaluminous quartzmonzonite to slightly peraluminous syenogranite. The epidote shows four textural relationships: three are primary and one is resulting from sub-solidus reaction. Euhedral epidote is dispersed and associated mainly with biotite and amphibole. In some cases euhedral crystals of the epidote contain allanite cores, which are subhedral to anhedral and constitute in average less than 20% of the whole grain. The contact between primary epidote and plagioclase is corroded, suggesting reaction with the host-magma. Secondary anhedral epidote is rare and results from plagioclase alteration. The preservation of magmatic epidote in granitic rocks emplaced in the upper crust is attributed to rapid magma ascent, which implies fast upward transport probably by dyking associated to shear zone. The REHC occurs between two transcurrent faults that impose an elongated shape, suggesting that magma filled fractures. The time of 14 years required for dissolution zones of 0.15 mm width of epidote on porphyritic quartz monzonite, corresponds to an average ascent rate of ≥ 700 m year-1 from 7.1 to 2.9 kbar.

A atividade petrolífera desenvolvida no CPCA/RN aborda as etapas de prospecção, avaliação de formação, exploração, perfuração, completação, elevação e produção, sendo possível a partir deste processo produtivo oportunizar a geração de emprego, renda, royalties, energia, combustível e projeção da região no cenário nacional. Este artigo tem por objetivo arrolar e classificar os impactos ambientais significativos do Campo Petrolífero Canto do Amaro – CPCA, localizado no baixo curso da Bacia Hidrográfica do Rio Apodi-Mossoró/RN – BHRAM/RN. A fundamentação teórica e metodológica da pesquisa se deu a partir da aplicação do sistema de avaliação Pressão-Estado-Impacto-Resposta – PEIR. Os aspectos e impactos ambientais mais significativos da indústria do petróleo constatados foram: geração de emissões atmosféricas, geração de resíduos semissólidos (lama e cascalho), geração de resíduos sólidos, geração de efluentes líquidos, geração de ruídos, poluição hídrica, poluição do solo, poluição sonora, poluição atmosférica, poluição visual, supressão vegetal, processos erosivos, interferência na flora local, interferência na fauna local, alteração da estabilidade dos ecossistemas, alteração da dinâmica de uso do solo, riscos à saúde dos trabalhadores, pressão nas comunidades locais, interferências nas atividades tradicionais e, pressão na infraestrutura de serviços públicos.  Para garantir a sustentabilidade da área investigada faz necessário realizar estudos de monitoramento ambiental (água, solo, ar, e, biota), diagnósticos socioeconômicos das comunidades locais, ações de gestão ambiental e auditoria ambiental.