Abstract:The "Polígono das Secas" is a region in the Northeast of Brazil that stands out by its low precipitation, high temperatures, and dry climate. Geoprocessing and the remote sensing techniques used in this research demonstrate the effectiveness for the monitoring of environmental resources. The objective of this work was to use the normalized difference water index (NDWI) in a comparative analysis of the reduction of the water surface area of the dry periods, November 2009 and December 2016, of the Capoeira Reservoir using images from the Landsat 5 TM satellite and Landsat 8 OLI, respectively. The results showed high values of NDWI in 2009, corresponding to La Niña period, with high precipitation and overflow of reservoirs. NDWI values in 2016 were low due to the low precipitations typical of El Niño periods. NDWI can be used to detect and monitor the presence of water and is an excellent tool to assist water monitoring agencies through the monitoring of rivers, lakes, and reservoirs in regions as the northeastern of Brazil.Key words: Water resources; Geoprocessing; Remote sensing; Semi-arid Resumo: O Polígono da Seca é uma região no Nordeste que se destaca por apresentar baixa precipitação, altas temperaturas e clima seco. As ferramentas do geoprocessamento e as técnicas de sensoriamento remoto podem ser utilizadas para demonstrarem a efetividade para o monitoramento de recursos ambientais. O objetivo foi utilizar o índice de diferença normalizada da água (NDWI) em uma análise comparativa da redução da área do espelho d'água dos períodos seco, novembro de 2009 e dezembro de 2016 da barragem Capoeira a partir das imagens do satélite Landsat 5 TM e Landsat 8 OLI., obtidas no site do Serviço Geológico dos Estados Unidos (USGS. Os resultados da comparação entre os anos apresentam altos valores de NDWI em 2009, o que corresponde a um alto teor de água, pois neste ano ocorreu uma maior precipitação, enchendo todo o reservatório, já os valores de NDWI em 2016 foram baixos, devido à baixa precipitação, desta forma, não havendo o aumento do volume considerável. O NDWI pode ser usado para detectar e monitorar a presença de água, sendo uma excelente ferramenta para auxiliar órgão fiscalizadores de recursos hídricos através do monitoramento de rios, lagos e reservatórios das regiões bem como é o caso na região Nordeste.Palavras-chave: Recursos hídricos; Geoprocessamento; Sensoriamento remoto; Semi-árido. Anjos et al. Denize Monteiro dos
The rabies virus propagates through several epidemiological cycles, which makes it difficult to control and predict. Thus, this study was structured with the aim of establishing the geospatial characterization of bat shelters in different semi-arid mesoregions of the state of Paraíba, Northeastern region of Brazil. Data provided by the Secretaria de Estado do Desenvolvimento da Agropecuária e da Pesca da Paraíba (SEDAP-PB), from 2007 to 2015 and data from digital platforms were used. The geographic representation was produced using the software QGIS 2.16.0 - Nodebo. To verify virus circulation sites, buffers were plotted within a 10-km radius from the registered shelters and rabies incidence sites in the state. A registry of 93 shelters in the period between 2007 and 2015 were distributed in 22 municipalities and 15 microregions. All mesoregions were represented, though 47.31% of the bat shelters were located in Agreste Paraibano. Of the total registered shelters, 66 (71%) are classified as artificial, and 27 (29%) as natural. The underreporting of rabies occurrences reveals the need to improve the registration of hematophagous bat shelters, specifically those for the D. rotundus species.
The changes that occur in ecosystems are increasingly coming from anthropogenic actions. In microbasins, these changes become more noticeable and can be detected using remote sensing techniques. The Rio da Cruz microbasin, meso-region of Sertão Paraibano. Field visits were made to identify the vegetation cover and forms of land use. Then, satellite images of the three-year rainy and dry periods were used: 2001, 2009 and 2017. The following steps were performed, image processing: pre-processing; processing and post-processing. Seven classes were selected: Arboreal Caatinga, Arboreal Shrub Caatinga, Anthropized Caatinga, Pastures and Agriculture, Rocky Outcrops, Water Bodies and Buildings. The results demonstrated an advance of the antropic action in the areas near the bodies of water. The temporal analysis of the watershed of the River of the Cross allowed to verify the reduction of the Arboreal Caatinga and increase of the Arboreal Shrub Caatinga, Anthropized Caatinga and Pasture and Agriculture areas in the studied years. Remote sensing techniques and knowledge of the microbasin result in relevant information on the use and cover of the land in years of regular precipitation and in conditions of greater precipitation, the arboreal vegetation is overestimated, making it difficult to identify anthropic areas during the rainy season.
No semiárido brasileiro, onde se insere o bioma caatinga, a precipitaçãos é um dos fator limitante para seu desenvolvimento sócioeconômico e ambiental, este estudo avaliou a correlação existente entre o nível de cobertura vegetal e as variáveis pluviométricas locais, considerando a climatologia de 2005 e 2015, utilizando-se imagens dos sensores TM e OLI dos satélites Landsat 5 e Landsat 8, respectivamente. O ano de 2005 apresentou maiores valores de NDVI em relação a 2015, com valores máximos de 0,71 e 0,78 no período seco e úmido, respectivamente. No ano de 2015, os valores máximos são de 0,64 e 0,61, para o período seco e úmido, respectivamente. Os maiores valores foram observados no período chuvoso de 2005, nas áreas de influência das estações meteorológicas de Matureia, Salgadinho e Areia de Baraúnas. No período seco, nota-se a baixa variabilidade dos valores de NDVI, sendo as maiores leituras observadas nas estações de Matureia, Salgadinho e Teixeira. As estações que apresentaram as maiores reduções nos valores de NDVI de 2005 para 2015, no período chuvoso, foram Matureia, Santa Teresinha e Salgadinho, com reduções de 41,9%, 38,2% e 32,7%, respectivamente. As correlações mais significativas foram estabelecidas para os períodos secos. As menores correlações foram verificadas no período chuvoso. A elevação dos níveis pluviométricos na região não implicou o aumento progressivo nos valores de NDVI. Palavras-chave: semiárido; geoprocessamento; índice de vegetação normalizada. Normalized difference vegetation index associated with pluviometric variables for Espinharas River sub-basin - PB/RN States ABSTRACT: In the Brazilian semiarid, where the caatinga biome is inserted, precipitation is a limiting factor for its socioeconomic and environmental development, This study evaluated the correlation between the level of vegetation cover and the local rainfall variables, considering the climatology of 2005 and 2015, using images from the TM and OLI sensors of the Landsat 5 and Landsat 8 satellites, respectively. The year 2005 presented higher NDVI values compared to 2015, with maximum values of 0.71 and 0.78 in the dry and wet periods, respectively. In 2015, the maximum values are 0.64 and 0.61, for the dry and wet periods, respectively. The highest values were observed in the rainy period of 2005, in the weather stations of Matureia, Salgadinho and Areia de Baraúnas. In the dry period, the low variability of NDVI values is noted, with the highest readings observed in the Matureia, Salgadinho and Teixeira platforms. The platforms that showed the greatest reductions in NDVI values from 2005 to 2015, in the rainy season, were Matureia, Santa Teresinha and Salgadinho, with reductions of 41.9%, 38.2% and 32.7%, respectively. The most significant correlations were established for the dry periods. The smallest correlations were found in the rainy season. The increase in rainfall levels in the region did not imply a progressive increase in NDVI values. Keywords: semiarid; geoprocessing; normalized difference vegetation index.
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