Consulta: subjectFacets:"EVI"
Registros recuperados: 16
Data/hora: 07/06/2024 09:23:56

Long-term association of Tyrannus savana and Sturnella superciliaris density with land cover and climatic variables in agroecosystems of Argentina
Provedor de dados: 68
Autores: Calamari,Noelia C; Cerezo Blandón,Alexis; Canavelli,Sonia B; Dardanelli,Sebastián; Gavier-Pizarro,Gregorio I; Zaccagnini,María E.
La expansión e intensificación agrícolas resultaron en importantes cambios en el paisaje agrícola de la Región Pampeana Argentina. Se utilizaron modelos lineales generalizados mixtos para analizar la relación entre la densidad de dos especies de aves, la Tijereta (Tyrannus savana) y el Pecho Colorado (Sturnella superciliaris), y variables ambientales asociadas a la cobertura, los usos de la tierra, la productividad vegetal y las condiciones climáticas. El área de estudio en la región central de Argentina se dividió en tres subregiones: (1) predominantemente agrícola, (2) agrícola-ganadera y (3) agrícola-ganadera bajo bosque nativo. Las aves fueron muestreadas anualmente durante 2003-2011 en 48 transectas de puntos localizadas en caminos secundarios. La...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Argentina; Densidad; EVI; Monitoreo biológico; Precipitaciones; Temperatura; Tendencia poblacional de aves; Uso de la tierra.
Ano: 2016
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0073-34072016000200005

Uso de imagens do sensor orbital modis na estimação de datas do ciclo de desenvolvimento da cultura da soja para o estado do Paraná – Brasil
Provedor de dados: 70
Autores: Johann,Jerry A.; Becker,Willyan R.; Uribe-Opazo,Miguel A.; Mercante,Erivelto.
RESUMO O Estado do Paraná caracteriza-se por uma grande variabilidade de épocas de semeadura (DS) e, consequentemente, pelo desenvolvimento máximo vegetativo (DMDV), colheita (DC) e ciclo (CI) para a cultura da soja. O objetivo deste trabalho foi estimar essas datas para o período de primavera-verão do ano-safra de 2011/2012, por meio de séries temporais de imagens do Índice de Vegetação Realçado (do inglês Enhanced Vegetation Index - EVI) do sensor Modis (Moderate Resolution Imaging Spectroradiometer). Gerou-se um perfil espectrotemporal médio de EVI, considerando todos os pixels mapeados como soja dentro de cada município. Estes dados serviram de entrada no software Timesat para estimar os decêndios do ciclo da cultura (DS, DMDV, DC e CI) por municípios....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ciclo fenológico; Índice de vegetação; EVI; Timesat.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162016000100126

IDENTIFICATION OF SUITABLE AREAS FOR IRRIGATED RICE CROPPING USING MODIS IMAGES AND HAND MODEL
Provedor de dados: 70
Autores: MENGUE,VAGNER P.; FONTANA,DENISE C.
ABSTRACT One of the most relevant activities of Brazilian economy is agriculture. Among the main crops in Brazil, rice is one of high relevance. The state of Rio Grande do Sul, in Southern Brazil, is responsible for 68.7% of domestic production (IBGE, 2013). The goal of this study was to develop a low-cost methodology with a regional scope to identify suitable areas for irrigated rice cropping in this state, using spectro-temporal behavior of vegetation index by means of MODIS images and HAND model. The rice-cropped area of this study was the southern half of the State. Using the HAND model, flood areas were mapped to identify irrigated rice cultivation. We used multi-temporal images of vegetation index from MODIS sensor, covering the period from August...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: HAND Model; EVI; MODIS; Irrigated rice; Mapping.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162016000200329

Influence of data acquisition geometry on soybean spectral response simulated by the prosail model
Provedor de dados: 70
Autores: Breunig,Fábio M.; Galvão,Lênio S.; Formaggio,Antonio R.; Epiphanio,José C. N.
View angle and directional effects significantly affect reflectance and vegetation indices, especially when daily images collected by large field-of-view (FOV) sensors like the Moderate Resolution Imaging Spectroradiometer (MODIS) are used. In this study, the PROSAIL radiative transfer model was chosen to evaluate the impact of the geometry of data acquisition on soybean reflectance and two vegetation indices (Normalized Difference Vegetation Index - NDVI and Enhanced Vegetation Index -EVI) by varying biochemical and biophysical parameters of the crop. Input values for PROSAIL simulation were based on the literature and were adjusted by the comparison between simulated and real satellite soybean spectra acquired by the MODIS/Terra and hyperspectral...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Leaf area index; NDVI; EVI; Reflectance; MODIS; Remote sensing.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162013000100018

DATA MINING TECHNIQUES FOR SEPARATION OF SUMMER CROP BASED ON SATELLITE IMAGES
Provedor de dados: 70
Autores: Becker,Willyan R.; Johann,Jerry A.; Richetti,Jonathan; Silva,Laíza C. DE A.
ABSTRACT: Due to the difficulty in discriminating soybean and corn in mappings obtained by the time series of satellite images, this study aimed to apply the data mining techniques to separate soybean and corn. Pure pixels selection from Landsat-8 were extracted and used to build a standard spectro-temporal EVI profile for both crops. These profiles were obtained with the Timesat software and, further incorporated in the Weka software. Five out of eleven variables of the standard spectro-temporal EVI profile for each crop were found through the decision tree, a data mining technique. These five variables were sufficient to achieve the separation of soybean and corn crops with an accuracy of 96.3% and a kappa index of 0.92.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Corn; EVI; J48; Soybean; Weka.
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162017000400750

Tendências temporais de índices de vegetação nos campos do Pampa do Brasil e do Uruguai
Provedor de dados: 86
Autores: Wagner,Ana Paula Luz; Fontana,Denise Cybis; Fraisse,Clyde; Weber,Eliseu José; Hasenack,Heinrich.
O objetivo deste trabalho foi avaliar a redução do vigor vegetativo da cobertura vegetal do Pampa do Brasil e do Uruguai, por meio da identificação de tendências negativas em séries temporais de imagens. Utilizaram-se séries temporais de imagens de NDVI/EVI do sensor Modis, de 2000 a 2011; imagens de índices de umidade do solo do "climate forecast system reanalysis"; e dados de precipitação pluvial de estações meteorológicas. O estudo quantificou tendências lineares e não lineares nas séries de NDVI e EVI, em áreas de campos. Na tendência monotônica de Mann-Kendall, a 5% de probabilidade, 81,9% da área total estudada foi significativa com o NDVI, e 74,8%, com o EVI; no entanto, o EVI apresentou contraste superior na estimativa dos parâmetros. Os resultados...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Campos nativos; EVI; Modis; NDVI; Séries temporais.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2013000900002

Correlations between spectral and biophysical data obtained in canola canopy cultivated in the subtropical region of Brazil
Provedor de dados: 86
Autores: Pinto,Daniele Gutterres; Fontana,Denise Cybis; Dalmago,Genei Antonio; Fochesatto,Elizandro; Vicari,Matheus Boni; Bremm,Carolina; Cunha,Gilberto Rocca da; Gouvêa,Jorge Alberto de; Santi,Anderson.
Abstract: The objective of this work was to identify the spectral bands, vegetation indices, and periods of the canola crop season in which the correlation between spectral data and biophysical indicators (total shoot dry matter and grain yield) is most significant. The experiment was carried out during the 2013 and 2014 crop seasons at Embrapa Trigo, in the state of Rio Grande do Sul, Brazil. A randomized complete block design was used, with four replicates, and the treatments consisted of five doses of nitrogen topdressing. Plant dry matter, grain yield, and phenology were measured. The canola spectral response was evaluated by measuring the canola canopy reflectance using a spectroradiometer, and, with this data, the SR, NDVI, EVI, SAVI, and GNDVI...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Brassica napus; EVI; GNDVI; NDVI; SAVI; Spectroradiometry.
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2017001000825

Modis time series for irrigated-area mapping in hydrographic basins of the Brazilian Northeastern region
Provedor de dados: 86
Autores: Ide,Andre Keiiti; Baptista,Gustavo Macedo de Mello.
Abstract: The objective of this work was to evaluate the applicability of time series of the enhanced vegetation index (EVI), from the moderate resolution imaging spectroradiometer (Modis), in the mapping of irrigated areas in the Northeastern region of Brazil. Annual time series from 2006 to 2015 were classified with the iterative self-organizing data analysis technique (Isodata) algorithm, generating a binary map of irrigated and nonirrigated areas for each year. In the Sertão region, the classification showed an average kappa coefficient of 0.66, underestimating the irrigated area by 7.6%, compared with data of the 2006 agricultural census. In regions more humid than the Sertão, such as Agreste and Zona da Mata Nordestina, the methodology showed...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Agricultural and environmental planning; EVI; Remote sensing; Semiarid; Vegetation index; Water resources management.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2018000100080

Análise quantitativa de parâmetros biofísicos de bacia hidrográfica obtidos por sensoriamento remoto
Provedor de dados: 86
Autores: Oliveira,Leidjane Maria Maciel de; Montenegro,Suzana Maria Gico Lima; Antonino,Antônio Celso Dantas; Silva,Bernardo Barbosa da; Machado,Célia Cristina Clemente; Galvíncio,Josiclêda Domiciano.
O objetivo deste trabalho foi avaliar quantitativamente os parâmetros biofísicos obtidos por sensoriamento remoto, para a área de abrangência da Bacia Hidrográfica do Rio Tapacurá, em Pernambuco. Utilizaram-se imagens do TM‑Landsat 5 de 10/7/1989, 6/7/2005 e 29/8/2007. As imagens foram registradas pela correção geométrica polinomial de primeira ordem. Foram realizadas as etapas de calibração radiométrica, reflectância, albedo planetário e transmissividade e, subsequentemente, geraram-se cartas temáticas de albedo e de temperatura da superfície, e do índice de vegetação melhorado ("enhanced vegetation index", EVI). O albedo da superfície apresentou valores médios crescentes entre as imagens obtidas em 1989 e 2005, o que indica expansão territorial urbana. A...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Albedo; EVI; Expansão territorial urbana; Monitoramento ambiental; Temperatura da superfície; TM‑Landsat 5.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2012000900005

Model for soybean production forecast based on prevailing physical conditions
Provedor de dados: 86
Autores: Gusso,Anibal; Arvor,Damien; Ducati,Jorge Ricardo.
Abstract: The objective of this work was to evaluate the reliability of the physiological meaning of the enhanced vegetation index (EVI) data for the development of a remote sensing-based procedure to estimate soybean production prior to crop harvest. Time-series data from the moderate resolution imaging spectroradiometer (Modis) were applied to investigate the relationship between local yield fluctuations of soybean and the prevailing physically-driven conditions in the state of Mato Grosso, located in the south of the Brazilian Amazon. The developed methodology was based on the coupled model (CM). The CM provides production estimates for early January, using images from the maximum crop development period. Production estimates were validated at three...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Agriculture; EVI; Modis; Remote sensing; Satellite.
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2017000200095

Phenological metrics of the grassland vegetation of Rio Grande do Sul, Brazil
Provedor de dados: 91
Autores: Moreira,Andreise; Fontana,Denise C.; Kuplich,Tatiana M.; Guasselli,Laurindo A.
ABSTRACT Considering that plant phenology studies allow establishing relationships between phenological patterns of vegetation and changes caused by climate variability, the aim of this study was to obtain phenological metrics for the predominant grassland typologies in Rio Grande do Sul State, Brazil (latitudes 27º 05’ and 33º 45’ S and longitudes 49° 43’ and 57º 39’ W) and to evaluate the spatial-temporal distribution pattern of these metrics under the influence of the subtropical climate variability. The phenological metrics were obtained based on the time series of the EVI (Enhanced Vegetation Index), of the sensor MODIS (Moderate Resolution Imaging Spectroradiometer), for the period from 2001 to 2014, through the Timesat program. Eleven phenological...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: EVI; Timesat; Time series.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662019001200899

Seasonal dynamics of vegetation indices as a criterion for grouping grassland typologies
Provedor de dados: 63
Autores: Moreira,Andreise; Bremm,Carolina; Fontana,Denise Cybis; Kuplich,Tatiana Mora.
ABSTRACT: This study aimed to characterize the average seasonal pattern of the vegetation in southern grassland in Brazil, and the variability found in the time series of vegetation indices. It also sought to identify similarities in the seasonal pattern of different grassland typologies. Moderate Resolution Imaging Spectroradiometer (MODIS), Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI) images from Feb to Dec, 2000 to 2014 were analyzed for ten regions. The grassland typologies studied showed EVI and NDVI profiles consistent with the seasonal dynamics of grassland vegetation under the influence of a subtropical climate, with highest values in the indices during the warm seasons of the year (spring and summer) and lowest...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: MODIS; EVI; NDVI; Phenology; Grassland vegetation.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162019000100024

Temporal profiles of vegetation indices for characterizing grazing intensity on natural grasslands in Pampa biome
Provedor de dados: 63
Autores: Junges,Amanda Heemann; Bremm,Carolina; Fontana,Denise Cybis; Oliveira,Carlos Alberto Oliveira de; Schaparini,Laura Pigatto; Carvalho,Paulo César de Faccio.
ABSTRACT The Pampa biome is an important ecosystem in Brazil that is highly relevant to livestock production. The objective of this study was to analyze the potential use of vegetation indices to discriminate grazing intensities on natural grasslands in the Pampa biome. Moderate Resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI) images from Jan to Dec, 2000 to 2013 series, were analyzed for natural grassland experimental units managed under high (forage allowance of 5 ± 2 % live weight – LW), moderate (13 ± 5 % LW) and low grazing intensity (19 ± 7 % LW). Regardless of intensity, the temporal profiles showed lower NDVI and EVI during winter, increased values in spring because of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: MODIS; NDVI; EVI; Green biomass; Stocking rate.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162016000400332

Variation of MODIS reflectance and vegetation indices with viewing geometry and soybean development
Provedor de dados: 42
Autores: Breunig,Fábio M.; Galvão,Lênio S.; Formaggio,Antônio R.; Epiphanio,José C.N.
Directional effects introduce a variability in reflectance and vegetation index determination, especially when large field-of-view sensors are used (e.g., Moderate Resolution Imaging Spectroradiometer - MODIS). In this study, we evaluated directional effects on MODIS reflectance and four vegetation indices (Normalized Difference Vegetation Index - NDVI; Enhanced Vegetation Index - EVI; Normalized Difference Water Index - NDWI1640 and NDWI2120) with the soybean development in two growing seasons (2004-2005 and 2005-2006). To keep the reproductive stage for a given cultivar as a constant factor while varying viewing geometry, pairs of images obtained in close dates and opposite view angles were analyzed. By using a non-parametric statistics with...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: NDWI; EVI; NDVI; Remote sensing; Directional effects.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652012000200004

Avaliação da dinâmica espectro-temporal visando o mapeamento dos principais cultivos de verão no Rio Grande do Sul
Provedor de dados: 53
Autores: Mengue,Vagner Paz; Fontana,Denise Cybis.
O objetivo deste trabalho foi desenvolver uma metodologia de baixo custo para o mapeamento das culturas de verão no Estado do Rio Grande do Sul, a partir do comportamento espectro-temporal de índices de vegetação e o Modelo HAND. O estudo foi realizado no Estado do Rio Grande do Sul, e o período foi a safra 2011/2012. Utilizaram-se imagens EVI do Sensor MODIS e dados SRTM. Para avaliar os resultados, foram usados dados de campo e dados do IBGE, além de um mapa referência elaborado com imagens RapidEye. Os resultados da classificação MODIS e os dados do IBGE geraram um coeficiente de correlação (r) de 0,98 para o arroz e 0,89 para a soja. Na validação dos dados coletados em campo, a cultura do arroz irrigado obteve um coeficiente Kappa de 0,66 e a cultura...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: MODIS; EVI; Modelo HAND; Agricultura.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052015000300331

Description of space-time variability of the potential productivity of Acacia caven espinales based on MODIS images and the Enhanced Vegetation Index (EVI)
Provedor de dados: 118
Autores: Gerstmann,Catalina; Miranda,Marcelo; Condal,Alfonso.
Acacia caven espinales are important communities of sclerophyllus vegetation in central Chile. To increase its productivity, it is necessary to study the community’s condition, their relationships with the surrounding environment and the interactions between them. The present study was carried out in a series of three years: 2004, 2005 and 2006. The 68 EVI images used represent the amount of radiation absorbed and emitted (from a Moderate Resolution Imaging Spectroradiometer) for the vegetation, which is related to the photosynthetic performance. The results show that during the summer and autumn seasons, there was more space homogeneity and less photosynthetic activity and potential productivity of the communities; in winter and spring, the period in...
Tipo: Journal article
Palavras-chave: Acacia caven; Potential productivity; EVI; MODIS; Spatial anisotropy.
Ano: 2010
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-16202010000100006