Bernardo Barbosa da Silva
@ppgmet.ufcg.edu.br
Professor Adjunto - Atmospheric Sciences Department
Universidade Federal de Campina Grande
RESEARCH, TEACHING, or OTHER INTERESTS
Atmospheric Science, Agricultural and Biological Sciences, Renewable Energy, Sustainability and the Environment, Computer Science
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Thomás R. Ferreira, Mitchell S. Maguire, Bernardo B. da Silva, Christopher M.U. Neale, Edivaldo A.O. Serrão, Jéssica D. Ferreira, Magna S.B. de Moura, Carlos A.C. dos Santos, Madson T. Silva, Lineu N. Rodrigues,et al.
Elsevier BV
Michele L. de Oliveira, Carlos A.C. dos Santos, Gabriel de Oliveira, Madson T. Silva, Bernardo B. da Silva, John E. de B.L. Cunha, Anderson Ruhoff, and Celso A.G. Santos
Elsevier BV
Rodolpho Medeiros, João Andrade, Desirée Ramos, Magna Moura, Aldrin Pérez-Marin, Carlos dos Santos, Bernardo da Silva, and John Cunha
MDPI AG
The Caatinga is the largest nucleus of Seasonally Dry Tropical Forests (SDTF) in the Neotropics. The leafing patterns of SDTF vegetation are adapted to the current environmental and climate variability, but the impacts of climate change tend to alter plants’ phenology. Thus, it is necessary to characterise phenological parameters and evaluate the relationship between vegetation and environmental drivers. From this information, it is possible to identify the dominant forces in the environment that trigger the phenological dynamics of the Caatinga. In this way, remote sensing represents an essential tool to investigate the phenology of vegetation, particularly as it has a long series of vegetation monitoring and allows relationships with different environmental drivers. This study has two objectives: (i) estimate phenological parameters using an Enhanced Vegetation Index (EVI) time-series over 20 years, and (ii) characterise the relationship between phenologic dynamics and environmental drivers. TIMESAT software was used to determine four phenological parameters: Start Of Season (SOS), End Of Season (EOS), Length Of Season (LOS), and Amplitude (AMPL). Boxplots, Pearson’s, and partial correlation coefficients defined relationships between phenologic dynamics and environmental drivers. The non-parametric test of Fligner–Killeen was used to test the interannual variability in SOS and EOS. Our results show that the seasonality of vegetation growth in the Caatinga was different in the three experimental sites. The SOS was the parameter that presented the greatest variability in the days of the year (DOY), reaching a variation of 117 days. The sites with the highest SOS variability are the same ones that showed the lowest EOS variation. In addition, the values of LOS and AMPL are directly linked to the annual distribution of rainfall, and the longer the rainy season, the greater their values are. The variability of the natural cycles of the environmental drivers that regulate the ecosystem’s phenology and the influence on the Caatinga’s natural dynamics indicated a greater sensitivity of the phenologic dynamics to water availability, with precipitation being the limiting factor of the phenologic dynamics. Highlights: The EVI time series was efficient in estimating phenological parameters. The high variability of the start of season (SOS) occurred in sites with low variability of end of the season (EOS) and vice versa. The precipitation and water deficit presented a higher correlation coefficient with phenological dynamics. Length of Season (LOS) and amplitude (AMPL) are directly linked to the annual distribution of rainfall.
Luís Romero Barbosa, Victor Hugo R. Coelho, Ana Claudia V.L. Gusmão, Lucila A. Fernandes, Bernardo B. da Silva, Carlos de O. Galvão, Nelson O.L. Caicedo, Adriano R. da Paz, Yunqing Xuan, Guillaume F. Bertrand,et al.
Elsevier BV
EWELYN REGINA ROCHA SILVA, DENILSON BARRETO DA LUZ, DENIS DE PINHO SOUSA, LUCAS BELÉM TAVARES, BERNARDO BARBOSA DA SILVA, and PAULO JORGE DE OLIVEIRA PONTE DE SOUZA
Brazilian Journal of Irrigation and Drainage - IRRIGA
ESTIMATIVA DO SALDO DE RADIAÇÃO DO AÇAÍ IRRIGADO POR MEIO DE SENSORIAMENTO REMOTO NO LESTE DA AMAZÔNIA EWELYN REGINA ROCHA SILVA 1; DENILSON BARRETO DA LUZ2; DENIS DE PINHO SOUSA3; LUCAS BELÉM TAVARES4; BERNARDO BARBOSA DA SILVA5 E PAULO JORGE DE OLIVEIRA PONTE DE SOUZA6 1 Mestre em Agronomia pelo programa de Pós-Graduação em Agronomia – PgAgro, Universidade Federal Rural da Amazônia, Av. Presidente Tancredo Neves, 2501, Terra Firme, 66077-830, Belém, Pará, Brasil, ewelynrocha@gmail.com. 2 Graduando em Agronomia, Laboratório de Agrometeorologia, Universidade Federal Rural da Amazônia, Av. Presidente Tancredo Neves, 2501, Terra Firme, 66077-830, Belém, Pará, Brasil, denilsong97@gmail.com. 3 Engenheiro Agrônomo, Doutor em Agronomia, Fiscal de Meio Ambiente na Secretaria de Estado de Meio Ambiente e Sustentabilidade do Pará, Rua do Utinga, n° 717, bairro Curió Utinga, CEP: 66610-010, Belém, PA, Brasil, denisdepinho@agronomo.eng.br. 4 Mestrando no programa de Pós-Graduação em Ciências Florestais, Universidade Federal Rural da Amazônia, Av. Presidente Tancredo Neves, 2501, Terra Firme, 66077-830, Belém, Pará, Brasil, lucas.belem.tavares@gmail.com. 5 Centro de Tecnologia e Recursos Naturais, Universidade Federal de Campina Grande, Rua Aprígio Veloso, 882, Campina Grande, 58429-900, Campina Grande, Paraíba, Brasil, bernardo.silva@ufcg.edu.br. 6 Instituto Socioambiental e dos Recursos Hídricos, Laboratório de Agrometeorologia, professor no programa de Pós-Graduação em Agronomia, Universidade Federal Rural da Amazônia, Av. Presidente Tancredo Neves, 2501, Terra Firme, 66077-830, Belém, Pará, Brasil, paulo.jorge@ufra.edu.br. 1 RESUMO Muitas áreas na Amazônia foram modificadas, alterando as trocas energéticas neste ambiente. Essa mudança é uma das responsáveis pelas variações no saldo de radiação (Rn), pois afetam a troca de energia entre a superfície e a atmosfera. O objetivo foi estimar o Rn em uma área de açaí irrigado na Amazônia Oriental. Foram utilizadas imagens do satélite Landsat 8, do dia sequencial do ano (DSA) 151/2018 e DSA 241/2019, referente às órbitas/pontos 222/61 e 223/61, respectivamente. O Rn foi obtido por meio do algoritmo Surface Energy Balance Algorithm for Land – SEBAL, que se fundamenta na radiância dos canais reflexivos e termal do sensor. Os resultados (sensor x superfície) mostraram-se satisfatórios com valores de erro absoluto médio (EAM) iguais a 4,92 W/m2 e 15,66 W/m2, erro relativo médio (ERM) iguais a 0,98 % e 3,4 % para DSA 151 e o DSA 241, respectivamente. Observou-se a capacidade do SEBAL em diferenciar tipos de coberturas do solo, o que proporcionou elaborar a distribuição espacial do Rn na cena analisada e no plantio de açaí, demostrando assim, a sensibilidade do modelo e a importância da variabilidade espacial existente na área, essas informações podem auxiliar as tomadas de decisões quanto ao manejo de irrigação. Keywords: sebal, variabilidade espacial, landsat 8. SILVA, E. R. R.; LUZ, D. B.; SOUSA; D. P.; TAVARES, L.B. SILVA, B. B.; SOUZA, P. J. O. P. ESTIMATION OF THE RADIATION BALANCE OF IRRIGATED AÇAÍ THROUGH REMOTE SENSING IN EAST AMAZONIA 2 ABSTRACT Many areas in the Amazon have been modified, altering the energy exchanges in this environment. This change is a factor responsible for variations in the radiation balance (Rn), as they affect the energy exchange between the surface and the atmosphere. The objective was to estimate the Rn in an açaí irrigated area in Eastern Amazon. Landsat 8 satellite images of the sequential day of the year (DSA) 151/2018 and DSA 241/2019, referring to orbits/points: 222/61 and 223/61, respectively, were used. The Rn was obtained through the Surface Energy Balance Algorithm for Land - SEBAL algorithm, which is based on the radiance of the reflective and thermal bands of the sensor. The results (sensor x surface) were satisfactory with mean absolute error (EAM) values equal to 4.92 W/m2 and 15.66 W/m2, mean relative error (ERM) equal to 0.98% and 3.4% for DSA 151 and DSA 241, respectively. SEBAL's ability to differentiate types of land cover was observed, which provided the elaboration of the spatial distribution of Rn in the analyzed scene and in the açaí planting, so demonstrating the sensitivity of the model and the importance of spatial variability in the area, this information can help in decision-making regarding irrigation management. Keywords: sebal, spatial variability, landsat 8.
Jussara Freire de Souza Viana, Suzana Maria Gico Lima Montenegro, Bernardo Barbosa da Silva, Richarde Marques da Silva, Raghavan Srinivasan, Celso Augusto Guimarães Santos, Diego Cezar dos Santos Araujo, and Clara Gadelha Tavares
Springer Science and Business Media LLC
Argemiro José Moreno Arteaga, Manoel Mariano Neto da Silva, Gabriel Vidal Mota, Salmi Lizzeth Tapia Aguirre, and Bernardo Barbosa da Silva
Instituto de Geografia, UNAM
Los ecosistemas forestales, como el bosque atlántico en América del sur, han sido removidos para dar lugar a actividades agropecuarias y asentamiento humanos. Tal situación estaría ocasionando cambios en la absorción de la energía solar en la superficie terrestre, lo que modifica el consumo de radiación neta, que, a su vez, puede influir en la temperatura del aire. Por consiguiente, esta investigación tuvo como objetivo evaluar las alteraciones de la radiación neta en la cuenca hidrográfica de Sorocaba, para analizar cómo el cambio de bosque atlántico por áreas agropecuarias y construcciones antrópicas impacta en la radiación neta y la repercusión que podría estar ocasionando en la regulación del clima local. Para esto fue determinado el balance de radiación en la cuenca y sus componentes biofísicos (NDVI, temperatura superficial, albedo y radiación emitida), por medio del modelo SEBAL, utilizando imágenes OLI/TIRS–Landsat 8 y ASTER(GDEM). Los resultados revelaron que las zonas construidas, seguidas por las agropecuarias, en comparación con la de bosque atlántico, presentan valores de albedo y temperatura superficial superiores, y, consecuentemente, mayores flujos de calor emitido a la atmósfera en forma de radiación infrarroja. Por consiguiente, se generó menores consumo de radiación neta, cuya media para las áreas boscosas, agrícolas, con pastos, suelos desnudos y construidas fue de 712,40Wm-2, 669,40Wm-2, 629,90Wm-2, 616,60Wm-2 y 524,40Wm-2, respectivamente. Así, la deforestación en la cuenca ocasionó que disminuyera la radiación neta y se emita más calor a la atmósfera, lo que favorece el efecto invernadero (principal causante del calentamiento global), en detrimento de poder regular la temperatura del aire.
Tainara T. S. Silva, Hugo O. C. Guerra, Bernardo B. da Silva, Cris L. M. Santos, Jean P. Guimarães, and Joelma S. dos Santos
FapUNIFESP (SciELO)
ABSTRACT The study aimed to estimate the evapotranspiration of banana (Musa spp.) in an irrigated perimeter of the municipality of Barbalha, CE, Brazil, using the Surface Energy Balance Algorithm for Land (SEBAL) model and to compare these results with those estimated using the Penman-Monteith method. Landsat-8 OLI/TIRS satellite images of May 22, 2016, August 10, 2016, and October 29, 2016 and data on temperature, relative humidity, wind speed and solar irradiance, obtained from an automatic weather station, installed close to the experimental area were used. The bands were stacked, and the stacked images were cut, then mathematical operations and evapotranspiration estimation were performed, whose actual daily banana values, estimated by the SEBAL algorithm, were 4.70; 5.00 and 6.50 mm, respectively, for May 22, August 10, and October 29, 2016. Comparing the daily ETr given by SEBAL with that obtained by the Penman-Monteith method, absolute errors of 0.26, 0.44, and 0.64 mm d-1 were observed for May 22, August 10, and October 29, 2016, respectively. These errors are within the ranges accepted in the literature.
Madson Tavares Silva, Eduardo da Silva Margalho, Edivaldo Afonso de Oliveira Serrão, Amanda Cartaxo de Souza, Caroline de Sá Soares, Carlos Antonio Costa dos Santos, and Bernardo Barbosa da Silva
FapUNIFESP (SciELO)
Abstract The type of land use and land cover plays a decisive role in land surface temperature (LST). As cities are composed of varied covers, including vegetation, built-up areas, buildings, roads and areas without vegetation, understanding LST patterns in complex urban spaces is becoming increasingly important. The present study investigated the relationship between LST and albedo, NDVI, NDWI, NDBI and NDBaI in the period between 1994 and 2017. Images from Thematic Mapper (TM) and Thermal Infrared Sensor (TIRS) onboard the Landsat 5 and 8 satellites, respectively, were used in the study. The images were processed, resampled (spatial resolution of 120 m) in the environment of the QGIS 3.0 software and, finally, centroids were extracted resulting in a total of 1252 points. A classical regression (CR) model was applied to the variables, followed by spatial autoregressive (SARM) and spatial error (SEM) models, and the results were compared using accuracy indices. The results showed that the highest correlation coefficient was found between albedo and NDBaI (r = 0.88). The relationship between albedo and LST (r = 0.7) was also positive and significant at р < 0.05. The global Moran's I index showed spatial dependence and non-stationarity of the LST (I = 0.44). The SEM presented the best accuracy metrics (AIC = 3307.15 and R2 = 0.65) for the metropolitan region of Belém, explaining considerably more variations in the relationship between explanatory factors and LST when compared to conventional CR models.
Lady L. M. Custódio, Bernardo B. da Silva, and Carlos A. C. dos Santos
FapUNIFESP (SciELO)
ABSTRACT Photosynthetically active radiation (PAR) comprises the spectral range of global solar radiation (Rs) that is highly related to vegetation productivity. The study aimed to evaluate the relationship between PAR and Rs in Petrolina, PE, and Brasília, DF, Brazil, with data measured in 2011 and 2013 at two stations of the Sistema Nacional de Organização de Dados Ambientais located in Petrolina, PE and Brasília, DF, Brazil, and the obtained models were evaluated using the measurements of 2014. It was verified that the PAR, in instantaneous values (μmol m-2 s-1), can be estimated at 2.31 times the Rs (W m-2) measured in Petrolina, while for daily values of PAR (MJ m-2) is equal to 50% of Rs (MJ m-2). In Brasília, PAR (μmol m-2 s-1) is 2.05 times the Rs (W m-2) and, in daily values, equal to 44% of Rs (MJ m-2). The variability of the PAR/Rs ratio followed the local variations of clearness index (Kt) and Rs. The models presented an adequate performance based on statistical indices mean absolute error, mean relative error, and root mean square error and can be used to estimate PAR.
Camilla K. Borges, Carlos A. C. dos Santos, Rayonil G. Carneiro, Lindenberg L. da Silva, Gabriel de Oliveira, Denis Mariano, Madson T. Silva, Bernardo B. da Silva, Bergson G. Bezerra, Aldrin M. Perez-Marin,et al.
Springer Science and Business Media LLC
Carlos A.C. dos Santos, Denis A. Mariano, Francisco das Chagas A. do Nascimento, Fabiane Regina da C. Dantas, Gabriel de Oliveira, Madson T. Silva, Lindenberg L. da Silva, Bernardo B. da Silva, Bergson G. Bezerra, Babak Safa,et al.
Elsevier BV
Carlos Roberto Silveira Jr, Laerte Guimarães Ferreira Junior, and Bernardo Barbosa Silva
Revista Brasileira de Geografia Fisica
Os satélites geoestacionários representam uma alternativa de alta resolução temporal para o monitoramento da superfície do solo em comparação com os satélites em órbita polar. Entretanto, em ângulos de visão elevados, alguns fatores influenciam a refletância da superfície, diminuindo a qualidade dos índices de vegetação, sendo importante o uso de técnicas de correção atmosférica e geométrica. Este artigo tem como objetivo avaliar dados do satélite de órbita geoestacionária MSG (Meteosat Second Generation) para obter o índice de vegetação de qualidade NDVI (Normalized Difference Vegetation Index) em regiões de alto ângulo de visão, tendo como área de estudo o estado de Goiás, no Brasil. As imagens MODIS (MODerate Image Spectroradiometer) foram utilizadas como referência para identificar características temporais das observações quanto à composição do produto e avaliar o desempenho das técnicas avaliadas. O período de estudo foi de 2013 a 2015. Como resultado, o NDVI MSG, obtido das 10h às 12h, horário local, fornece uma imagem com 95% de cobertura de pixel, em 12 dias, enquanto o MOD09 a obtém em 16 dias. A correção geométrica é um ajuste fino que não apresentou maior correlação de dados. Por outro lado, a correção atmosférica mantém a correlação dos dados e aumenta o valor do NDVI, aproximando-o do valor do NDVI MODIS. Executando uma aplicação PCA (Principal Component Analysis) usando a técnica de classificação k-means não supervisionada, o NDVI MSG forneceu resultados superiores em comparação ao MODIS, demonstrando o potencial de dados geoestacionários para o monitoramento da superfície do soloEvaluation of techniques for improvement of NDVI MSG quality for soil surface monitoringA B S T R A C TGeostationary satellites represent a high temporal resolution alternative for ground surface monitoring compared to polar orbiting satellites. However, at high viewing angles, some factors influence surface reflectance, decreasing the quality of vegetation indices, reason why it is important to use atmospheric and geometric correction techniques. This article aims to evaluate data from the MSG (Meteosat Second Generation) geostationary orbit satellite to obtain the NDVI (Normalized Difference Vegetation Index) quality vegetation index in high viewing angle regions, having as study area the state of Goiás, in Brazil. MODIS (MODerate Image Spectroradiometer) images were used as a reference to identify temporal characteristics of the observations for product composition and to evaluate the performance of the evaluated techniques. The study database period was 2013-2015. As a result, the NDVI MSG, obtained from 10:00 to 12:00 local time, provides an image with 95% pixel coverage, within 12 days, while MOD09 gets it within 16 days. Geometric correction is a fine-tuning that did not present increased correlation of data. On the other hand, atmospheric correction maintains the correlation of the data and increases the value of NDVI, bringing it closer to the NDVI MODIS value. Performing a PCA (Principal Component Analysis) application using the unsupervised k-means classification technique, NDVI MSG provided superior results compared to MODIS, demonstrating the potential of geostationary data for soil surface monitoring.Keywords: MSG, NDVI, 6S, BRDF, geostationary orbit satellite
Carlos Roberto Silveira Jr, Laerte Guimarães Ferreira Jr, and Bernardo Barbosa Silva
Revista Brasileira de Geografia Fisica
O satélite de órbita geoestacionária Meteosat-10 fornece indicadores ambientais com alta resolução temporal e baixa resolução espacial, permitindo o monitoramento da fenologia da paisagem. Porém, devido ao alto ângulo de visada do Meteosat-10, pouco tem sido utilizado para o Brasil. Indicadores como NDVI (Normalized Difference Vegetation Index), eficiente para o monitoramento da vegetação devido à simplicidade e estreita relação com a produtividade da vegetação, e o NDWI (Normalized Difference Water Index), que indica a umidade da superfície do solo combinando o solo e a vegetação expostos, ajudam a compreender a sazonalidade ambiental e ocupação das bacias hidrográficas. Esse artigo tem como objetivo avaliar a capacidade de indicadores biofísicos, provindos do satélite de órbita geoestacionária Meteosat-10, para o monitoramento ambiental da superfície do solo, tendo como área de estudo bacias hidrográficas, Ottobacias nível 5, do estado de Goiás, incluindo o Distrito Federal, no período 2013 a 2015. Para tanto, foram avaliados o NDVI, NDWI e a precipitação com resolução temporal de 12 dias e mensal. Fez-se o cálculo dos indicadores normalizados SPI (Standard Precipitation Index), SVI (Standard Vegetation Index) e SWI (Standard Water Index) para comparações entre os anos e obtenção da tendência de cada indicador. Como resultado pode-se identificar e compreender padrões sazonais das bacias hidrográficas em diferentes regiões e classes de uso, demonstrando o potencial de indicadores de vegetação provenientes de satélites geoestacionários, para o monitoramento da cobertura do solo em bacias hidrográficas, bem como identificar a maior sensibilidade do NDWI para o monitoramento de mudanças ocorridas na superfície. Monitoring of soil surface using environmental indicators satellite data monitor from geostationary orbit A B S T R A C TThe geostationary orbit satellite Meteosat-10, has spectral bands that allow create that provides environmental indicators with high temporal resolution and low spatial resolution, allowing the monitoring of landscape phenology. However, for Brazil little has been used due to the high viewing angle of Meteosat-10 (45 a 80º). Indicators like NDVI (Normalized Difference Vegetation Index), efficient for monitoring vegetation due to the simplicity and close relationship with the productivity of the vegetation, and the NDWI (Normalized Difference Water Index), which indicates the moisture of the soil surface combining the soil and the exposed vegetation, help to understand the environmental seasonality and occupation of watersheds. This article aims to evaluate the capacity of biophysical indicators, coming from the geostationary orbit satellite Meteosat-10, for the environmental monitoring of the soil surface, with hydrographic basins, Ottobasin level 5, from the state of Goiás, as the study area. Distrito Federal, from 2013 to 2015. For this purpose, NDVI, NDWI and precipitation with 12-day and monthly resolution were evaluated. Standardized indicators SPI (Standard Precipitation Index), SVI (Standard Vegetation Index) and SWI (Standard Water Index) were calculated for comparisons between years and obtaining the trend of each indicator. As a result, it is possible to identify and understand seasonal patterns of hydrographic basins in different regions and classes of use, demonstrating the potential of vegetation indicators from geostationary satellites, for monitoring soil cover in hydrographic basins, as well identify the highest sensitivity NDWI for monitoring surface changes.Keywords: NDVI, NDWI, Meteosat-10, environmental monitoring.
E. P. CAVALCANTI, B. B. SILVA, V. P. R. SILVA, and J. B. CHAVES
Instituto de Geociencias - UFRJ
The determination of the wind energy potential is relevant to the management and monitoring of wind farms, particularly for the purpose of electricity generation. In this work, the 10m-wind speed data, obtained from the European Centre for Medium-Range Weather Forecasts (ECMWF) ERA-Interim, were used to evaluate its seasonal and interannual variability in the Northeast region of Brazil. The results indicate that spring is the season with the highest wind intensity, while autumn is the season with the lowest wind intensity. During El Niño years the wind is stronger than average (exceeding 45% in the autumn and up to 25% in the spring), while in La Niña years it is below average in areas with higher average wind potential (40% in the autumn and up to 30% in the spring). Positive Atlantic Ocean Sea Surface Temperature (SST) Gradient / Dipole episodes bring more intense than normal winds (up to 35% in the northern part of the region), as opposed to years of negative Gradient / Dipole events where winds are below average (until 40% in the autumn).
Carlos Roberto Silveira Jr, Laerte Ferreira Guimaraes, and Bernardo Barbosa Silva
Revista Brasileira de Geografia Fisica
O monitoramento da cobertura do solo a partir de indicadores ambientais possibilita melhor conhecimento dos processos biofísicos e ecológicos, auxiliando na compreensão da dinâmica do uso da terra e na tomada de decisão. Satélites em órbita polar, em sua maioria, fornecem o NDVI (Normalized Difference Vegetation Index) com média resolução espacial (250 m a 1 km) a partir de composições de imagens (7, 10 ou 16 dias). Por outro lado, satélites em órbita geoestacionária podem fornecer o NDVI com baixa resolução espacial (1 a 3 km) e alta resolução temporal (10 a 25 minutos). Particularmente, o MSG (Meteosat Second Generation) mostra-se eficiente para o monitoramento da vegetação a partir do índice NDVI para regiões da África, apresentando alta correlação espacial com dados de satélites polares, sendo utilizado na análise e detecção do estresse hídrico da vegetação e da fenologia com vantagens significativas na análise de séries. No entanto, para o Brasil, existem limitações que precisam ser conhecidas para o desenvolvimento do produto NDVI MSG com qualidade. Este artigo tem como objetivo apresentar como o MSG é utilizado para o monitoramento de processos da superfície a partir do NDVI, com o intuito de identificar os desafios inerentes no desenvolvimento do produto para o Brasil. Para tanto, são apresentas as principais características do NDVI, o histórico do produto de cobertura global e uma discussão sobre os principais desafios do NDVI MSG para o Brasil, relacionados às características de baixa resolução espacial, visada sobre o Brasil, correções atmosférica e geométrica e características da imagem pancromática e canais espectrais. Characteristics and challenges of NDVI generation to Brazil from Meteosat-10 geostationary orbit satellite dataA B S T R A C TMonitoring land cover from environmental indicators enables a better understanding of biophysical and ecological processes, helping to understand the dynamics of land use to make decisions. Polar orbit satellites, for the most part, provide NDVI (Normalized Difference Vegetation Index) products with medium spatial resolution (250 m to 1 km) from image compositions (7, 10 or 16 days). On the other hand, geostationary orbit satellites provide NDVI with low spatial resolution (1 to 3 km) and high temporal resolution (10 to 25 minutes). Particularly, the MSG is efficient for the monitoring of vegetation from the NDVI index for regions of Africa, having a high spatial correlation with data from polar satellites, have been used in the analysis and detection of water stress of vegetation and phenology with significant advantages in the time series analysis. However, for Brazil, there are limitations that need to be known for developing NDVI MSG product quality. This paper aims to present how the MSG is used to monitor surface processes from the NDVI vegetation index, in order to identify the challenges inherent in product development for Brazil. For this, the main features of the NDVI are presented, the history of the global coverage product and a discussion about the main challenges of the NDVI MSG for Brazil, related to low spatial resolution on Brazil, atmospheric and geometric corrections and characteristics of the panchromatic image and the spectral channels.Keywords: Meteosat-10, NDVI, environmental index.
A. C. S. LEITE, L. M. M. OLIVEIRA, B. B. SILVA, S. M. G. L. MONTENEGRO, and U. A. BEZERRA
Instituto de Geociencias - UFRJ
A expansao urbana promove a supressao vegetal bem como a alteracao no balanco de energia, acarretando mudancas climaticas, como por exemplo, a elevacao do campo termico urbano. Nesse sentido, esta pesquisa teve por objetivo investigar, com base em imagens multiespectrais, as variacoes espaco-temporais da temperatura da superficie relacionadas ao crescimento da urbanizacao no municipio de Teresina – PI - Brasil. Para tanto, foram empregados o Indice de Construcao da Diferenca Normalizada (NDBI) e o parâmetro biofisico temperatura da superficie (Tsup), gerados com imagens dos sensores TM - Landsat 5 e OLI/TIRS - Landsat 8. Verificou-se, com base nas cartas tematicas do NDBI e Tsup, que de 1995 a 2015, se observou substancial elevacao da temperatura superficial concomitante ao incremento de superficies construidas e impermeaveis, principalmente nos extremos da zona urbana municipal. Alem disso, a media dos indicadores empregados, obtidas por zona do municipio, evidenciou as alteracoes na temperatura e na urbanizacao no periodo analisado. O coeficiente de correlacao linear entre as variaveis Tsup e NDBI apresentou forte correlacao positiva entre a expansao urbana e o crescimento do campo termico da superficie. Assim, Tsup e NDBI se mostraram indicadores consistentes das alteracoes da superficie terrestre no perimetro urbano de Teresina - PI - Brasil.
Jussara Viana, Suzana Montenegro, Bernardo Silva, Richarde Silva, and Raghavan Srinivasan
Journal of Urban and Environmental Engineering
The aim of this research is to estimate the sediment yield in the Pirapama River Basin and in the area of contribution of the Pirapama Reservoir and to identify areas susceptible to soil erosion for identification of critical erosion watersheds during the period from 2000 to 2010. This study was conducted to design a framework for evaluating and identifying critical erosion in Pirapama watershed, based on the tolerable erosion concept, by using the Soil and Water Assessment Tool (SWAT) model. SWAT was calibrated and validated for two streamflow stations (Cachoeira Tapada and Destilaria Inexport) for the period from 2000 to 2010. The results show that the simulated data for Cachoeira Tapada station were considered good (NS = 0.68 and R² = 0.71) and very good (PBIAS = 1.46%). Regarding the statistical data in the validation, the values of NS (0.67), R² (0.85), and PBIAS (19.18%) were considered good, very good, and satisfactory, respectively. The statistical data obtained in the calibration of the model for the fluviometric station Destilaria Inexport indicated that the simulated data are considered very good, with R² = 0.84, NS = 0.81, and PBIAS = 2.33%. In the validation, the statistics showed values consistent with the literature, with NS = 0.72, R² = 0.86, and PBIAS = –19.11%, which are considered good, very good, and satisfactory, respectively. The estimated average sediment yield in the Pirapama River basin ranged from 0.10 to 129.90 ton/ha.year. The results of the sediment yield estimates in the contribution area of the Pirapama Reservoir showed that the mean sediment yield of the sub-basins upstream of the Pirapama Reservoir was 61.49 ton/ha.year for the period analysed. According to the annual estimates performed, 5.59 ton/ha.year of this amount reaches the Pirapama Reservoir, which corresponds to 9% of the soil losses incident in the area. Thus, the sub-basins upstream of the Pirapama Reservoir were identified as portions of the basin that are susceptible to the erosion process. Sediment yield in these portions can interfere with the volume of water of the Pirapama Reservoir when the eroded material is carried to the depth of the lake.
Fernandha Batista Lafayette, Suzana Maria Gico Lima Montenegro, Artur Paiva Coutinho, Willames Soares, Antônio Celso Dantas Antonino, Bernardo Barbosa da Silva, and Ana Emília Carvalho de Gusmão da Cunha Rabelo
FapUNIFESP (SciELO)
ABSTRACT In semi-arid regions, there is a high evaporation, which leads to soil dryness, interfering in the availability of water in the soil. Usually it is difficult to measure and model the evaporation due to the complexity of the available methods, the low soil water content and the low concentration of water vapor in the air. This can also make it difficult to monitor and simulate the evapotranspiration in these regions. Thus, the Portable Chamber method is used to directly measure evaporation and evapotranspiration, because this technique allows real time estimation and in short time intervals, giving a more detailed estimation of those processes. The objective of this study was to evaluate the evaporation through the mass transfer in the soil in an underground dam under different water table depths and conditions of the semi-arid environment of Pernambuco State in Brazil, through the values predicted by the SiSPAT model and measured by the portable chamber method. For the purposing of modeling and also to better know the soil behavior, soil hydraulic properties were determined though the Beerkan method. The portable chamber method was applied for one of the first times in a semi-arid region of Northeastern Brazil, and it was consistent with the potential evaporation of bare soil, reaching about 1,800 mm per year. The SiSPAT model was quite satisfactory for simulation of soil evaporation in different conditions of the water table depth. The values found for soil evaporation with the simulation of the SiSPAT and the Portable Chamber (PC) method differed in 1.43% and 4.44% for cases where the water table was at 0.20 and 1.20m of depth, respectively.
Argemiro L. Araújo, Madson T. Silva, Bernardo B. da Silva, Carlos Antonio Costa dos Santos, and Milena P. Dantas
FapUNIFESP (SciELO)
Resumo Este estudo avaliou as mudanças ocorridas no NEB por meio da análise espaço-temporal do albedo, NDVI e Ts obtidas com base no sensor MODIS no período de 2002 a 2011. Os dados obtidos por sensoriamento remoto foram associados a dados de precipitação obtidos por técnicas de reanálise para avaliação das áreas de interesse e seus respectivos pontos de amostras selecionados. O albedo apresentou mais de 75% de seus dados na faixa de 0,10 a 0,20 e os valores de Ts foram superiores a 28 °C em 88% dos pontos. As análises do NDVI e da precipitação apontaram que 73% e 76% dos dados foram superiores a 0,50 e a 1900 mm/ano, respectivamente. Foram observados aumentos significativos de Ts em anos que mais de 75% dos dados de precipitação estiveram abaixo dos 1500 mm/ano e crescimento de NDVI associado a anos de aumento da precipitação. O teste de Mann-Kendall ao nível de 5% apontou a ocorrência de tendências significativas apenas para os alvos nas áreas de caatinga e cerrado. Os maiores valores de NDVI se situaram em áreas de clima tropical úmido e de clima equatorial, com valores acima de 0,70.
Vicente de PR da Silva, Inajá Francisco de Sousa, Alexandra L Tavares, Thieres George F da Silva, Bernardo B da Silva, Romildo M de Holanda, José Ivaldo B de Brito, Célia C Braga, Enio P de Souza, and Madson T Silva
FapUNIFESP (SciELO)
ABSTRACT The water scarcity is expected to intensify in the future and irrigation becomes an essential component of crop production, especially in arid and semiarid regions, where the available water resources are limited. Four field experiments were carried out at tropical environment in Brazil in 2013 and 2014, in order to evaluate the effect of planting date on crop evapotranspiration (ETc), crop coefficient (Kc), growth parameters and water use efficiency (WUE) of coriander (Coriandrum sativum) plants. The planting dates occurred during winter, spring, summer and autumn growing seasons. ETc was obtained through the soil water balance method and the reference evapotranspiration (ETo) through the Penman-Monteith method, using data collected from an automatic weather station located close to the experimental area. The results of the research showed that the mean values of coriander ETc and Kc were 139.8 mm and 0.87, respectively. Coriander water demand is higher in the summer growing season and lower in the winter; however, its yield is higher in the autumn and lower in the winter. Coriander has higher yield and development of its growth variables in the autumn growing season. The results also indicated that the interannual climate variations had significant effects on most growth variables, as yield, ETc and Kc of coriander grown in tropical environment.
Argemiro Lucena de Araújo, Madson Tavares Silva, Bernardo Barbosa da Silva, Carlos Antonio Costa dos Santos, and Marcos Renato Basílio do Amorim
FapUNIFESP (SciELO)
Resumo Este estudo apresenta uma metodologia simplificada e ajustada a partir de algoritmos existentes a dados de sensores orbitais disponíveis para a região Nordeste do Brasil (NEB) com o intuito de operacionalizar a determinação espacial da evapotranspiração (ET) apenas com dados de sensoriamento remoto, utilizando dados MODIS/Terra do período de 2002 a 2011. Os resultados obtidos para diversos alvos espalhados pelo NEB foram comparados a dados CLM (Common Land Model) e MOD16. Obteve-se erro médio percentual (EMP) e erro médio absoluto (EMA) da ordem de 23,6% e 181 mm.ano−1, respectivamente, nos valores de ET quando comparados a dados CLM. Avaliou-se a ET obtida pelo algoritmo proposto, com dados de ET do produto MOD16, o que resultou em valores de EMP e EMA de 38,6% e 288 mm.ano−1, respectivamente. Os dados médios anuais da ET variaram de 482 a 1105 mm.ano−1 relativos a áreas de Caatinga e floresta tropical pluvial, respectivamente. Os resultados apresentaram-se condizentes com a literatura e evidenciaram que a metodologia proposta possibilita operacionalizar o cômputo da ET em toda a região Nordeste, não obstante a grande heterogeneidade topográfica e climática da região.