Consulta: subjectFacets:"MODIS"
Registros recuperados: 28
Data/hora: 01/06/2024 09:21:13

Dinámica de la fenología de la vegetación a partir de series temporales de NDVI de largo plazo en la provincia de La Pampa
Provedor de dados: 67
Autores: Vázquez,Pablo; Adema,Eduardo; Fernández,Beatriz.
La cubierta vegetal es un indicador natural de la salud ambiental y tendencia climática, y la actividad fotosintética permite detectar esas variaciones. No obstante, su evaluación a escala de región es una tarea complicada debido a la escasez de inventarios multitemporales. La teledetección ha facilitado el estudio de la dinámica y distribución espacial de la vegetación a partir de un estimador del índice de área foliar y de la fracción de la radiación fotosintéticamente activa interceptada, conocido como índice verde normalizado (NDVI). La provincia de La Pampa cuenta con un estudio de composición y distribución florística a escala de paisaje y región, donde se reconocen procesos de degradación. El objetivo de este trabajo fue caracterizar la dinámica de...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Patrones temporales; Biometría; NOAA; MODIS; Degradación ambiental; Cambio climático.
Ano: 2013
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1667-782X2013000200001

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

Identification of croplands of winter cereals in Rio Grande do Sul state, Brazil, through unsupervised classification of normalized difference vegetation index images
Provedor de dados: 70
Autores: Junges,Amanda H.; Fontana,Denise C.; Pinto,Daniele G.
This study aimed to propose methods to identify croplands cultivated with winter cereals in the northern region of Rio Grande do Sul State, Brazil. Thus, temporal profiles of Normalized Difference Vegetation Index (NDVI) from MODIS sensor, from April to December of the 2000 to 2008, were analyzed. Firstly, crop masks were elaborated by subtracting the minimum NDVI image (April to May) from the maximum NDVI image (June to October). Then, an unsupervised classification of NDVI images was carried out (Isodata), considering the crop mask areas. According to the results, crop masks allowed the identification of pixels with greatest green biomass variation. This variation might be associated or not with winter cereals areas established to grain production. The...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Wheat; Black oat; Remote sensing; MODIS; NDVI.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162013000400027

Data mining techniques for identification of spectrally homogeneous areas using NDVI temporal profiles of soybean crop
Provedor de dados: 70
Autores: Johann,Jerry A.; Rocha,Jansle V.; Oliveira,Stanley R. de M.; Rodrigues,Luiz H. A.; Lamparelli,Rubens A. C.
The aim of this study was to group temporal profiles of 10-day composites NDVI product by similarity, which was obtained by the SPOT Vegetation sensor, for municipalities with high soybean production in the state of Paraná, Brazil, in the 2005/2006 cropping season. Data mining is a valuable tool that allows extracting knowledge from a database, identifying valid, new, potentially useful and understandable patterns. Therefore, it was used the methods for clusters generation by means of the algorithms K-Means, MAXVER and DBSCAN, implemented in the WEKA software package. Clusters were created based on the average temporal profiles of NDVI of the 277 municipalities with high soybean production in the state and the best results were found with the K-Means...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Annual crop; MODIS; SPOT Vegetation; MAXVER; K-Means.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162013000300008

Perfis temporais NDVI MODIS, na cana-soca, de maturação tardia
Provedor de dados: 70
Autores: Ramme,Fernando L. P.; Lamparelli,Rubens A. C.; Rocha,Jansle V.
Este artigo descreve o desenvolvimento de um banco de dados relacional e de uma ferramenta para a visualização de perfis temporais do NDVI MODIS, a partir dos dados do produto MOD09Q1, referente ao fator de refletância bidirecional de superfície relativa ao comprimento de onda do vermelho e do infravermelho-próximo, composição temporal em mosaicos de 8 dias, e a banda de controle de qualidade, dos talhões de cana-de-açúcar no Estado de São Paulo, para analisar a maturação da cana-soca Tardia. Das fazendas de cana-de-açúcar são obtidos os dados de históricos sobre produtividade, solo, variedade, localização de cada pixel para cada microrregião monitorada. Todos os dados são integrados em um banco de dados desenvolvido em PostgreSQL. O aplicativo foi...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: MODIS; Curvas espectrais; Índice de vegetação; Cana-de-açúcar.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162010000300012

Determination of total accumulated rainfall, global radiation, evapotranspiration and degree-days originated from the ECMWF model to sugar cane crop
Provedor de dados: 70
Autores: Moraes,Rafael A.; Rocha,Jansle V.; Lamparelli,Rubens A. C.
The climate variability between the growth and harvesting of sugar cane is very important because it directly affects yield. The MODIS sensor has characteristics like spatial and temporal resolution that can be applied to monitoring of vegetative vigor variability in the land surface and then, temporal profiles generation. Agro meteorological data from ECMWF model are free and easy to access and have a good representation of reality. In this study, we used the period between sugar cane growth and harvest in the state of Sao Paulo, Brazil, from temporal profiles selecting of NDVI behavior. For each period the precipitation, evapotranspiration, global radiation, length (days) and degree-days were accumulated. The periods were presented in a map format on...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Agro meteorological variable; ECMWF; MODIS; Sugar cane.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162014000200013

ESTIMATION OF THE FRACTION OF CANOPY COVER FROM MULTISPECTRAL DATA TO BE USED IN A WATER SOIL EROSION PREDICTION MODEL
Provedor de dados: 72
Autores: González Lanteri,David; Huete,Alfredo; Kim,HoJin; Didan,Kamel.
Using the 16 day MODIS (aboard the EOS Terra satellite) 250m NDVI and ground biophysical and spectral measurements we established simple relationships between these parameters and the canopy cover. The canopy cover is used in water erosion models to estimate the amount of soil loss under precipitation events and specific geographic conditions. Two transects, in the grassland part of the Walnut Gulch Experimental Watershed (WGEW) located near the town of Tombstone in Arizona, were established for ground data collection. Ground measurements were performed every 16 days, to coincide with the Terra Satellite overpass. Erosion, in desert environment is a contributing factor to soil degradation and subsequently desertification. Erosion is strongly related with...
Tipo: Journal article
Palavras-chave: Canopy cover; MODIS; Soil erosion; Semi arid environment.
Ano: 2004
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-65382004000200043

VERTICAL TEMPERATURE AND MOISTURE STRUCTURE IN LOWER ATMOSPHERE RETRIVED FROM TERRA/MODIS
Provedor de dados: 72
Autores: Kim,Y. S; Kwon,B. H; Hong,K. M.
Two MODIS instruments on board the Terra and Aqua Satellites are operational for global remote sensing of the land, ocean and atmosphere. Atmospheric sounding data with a high spatial resolution from MODIS will provide a wealth of useful information. The vertical air temperature and moisture data were retrieved using the MODIS data, and compared with the radiosonde data obtained in the Korean Peninsula. The correlation coefficients are 0.99 and 0.89 for air temperature and moisture cases, respectively. Air temperature data were relatively good agreement, but the moisture data from MODIS were underestimated
Tipo: Journal article
Palavras-chave: MODIS; Radiosonde; Vertical profile.
Ano: 2004
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-65382004000200058

Monitoramento espaço-temporal da cana-de-açúcar a partir de índices espectrais de vegetação.
Provedor de dados: 14
Autores: PAZ, A. R. da; VICTORIA, D. de C.; OLIVEIRA, A. F. de; ANDRADE, R. G.
Para culturas agrícolas que abrangem grandes áreas, como é o caso da cana-de-açúcar no Brasil, técnicas de geoprocessamento aplicadas a imagens orbitais de alta resolução temporal apresentam grande potencial de mapear e monitorar os ciclos fenológicos/agronômicos das lavouras. Para essa finalidade, destaca-se o uso de séries temporais de índices espectrais de vegetação (IV) como NDVI (Normalized Difference Vegetation Index) e EVI (Enhanced Vegetation Index) calculados a partir das imagens orbitais de reflectância. Este documento apresenta resultados de uma pesquisa que avaliou a utilização de um método de suavização de perfis temporais de IV e a posterior derivação de parâmetros do ciclo fenológico/agrícola de talhões de cana-de-açúcar, com o objetivo de...
Tipo: Documentos (INFOTECA-E)
Palavras-chave: MODIS; Série Temporal; Monitoramento Agrícola.; Sensoriamento Remoto.
Ano: 2009
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/662065

Estimating turbidity and total suspended matter in the Adour River plume (South Bay of Biscay) using MODIS 250-m imagery
Provedor de dados: 5
Autores: Petus, Caroline; Chust, Guillem; Gohin, Francis; Doxaran, David; Froidefond, Jean-marie; Sagarminaga, Yolanda.
The Basque coastal waters (South Bay of Biscay) are directly influenced by the Adour River freshwater plume. The Adour outflow leads to important variations of suspended matter concentrations and turbidity, which in turn may affect biological productivity and water quality. This study aims at both developing specific algorithms and testing the efficiency of atmospherically corrected MODIS-Aqua 250-m surface reflectance product (MYD09) to map total suspended matter concentrations and turbidity within the Adour coastal region. First, regional empirical algorithms based on in-situ data were tested to retrieve the concentration of total suspended matter and turbidity from the remote sensing reflectance. Then, the respective sensitivity of MODIS surface...
Tipo: Text
Palavras-chave: Adour River plume; Turbidity; Suspended matter; Satellite sensing; MODIS; Remote sensing reflectance.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00003/11383/8042.pdf

The relationship between Suspended Particulate Matter and Turbidity at a mooring station in a coastal environment: consequences for satellite-derived products
Provedor de dados: 5
Autores: Jafar-sidik, Madihah; Gohin, Francis; Bowers, David; Howarth, John; Hull, Tom.
From a data set of observations of Suspended Particulate Matter (SPM) concentration, Turbidity in Formazin Turbity Unit (FTU) and fluorescence-derived chlorophyll-a at a mooring station in Liverpool Bay, in the Irish Sea, we investigate the seasonal variation of the SPM:Turbidity ratio. This ratio changes from a value of around 1 in winter (minimum in January–February) to 2 in summer (maximum in May–June). This seasonal change can be understood in terms of the cycle of turbulence and of the phytoplankton population that affects the nature, shape and size of the particles responsible for the Turbidity. The data suggest a direct effect of phytoplankton on the SPM:Turbidity ratio during the spring bloom occurring in April and May and a delayed effect, likely...
Tipo: Text
Palavras-chave: Turbidity; Suspended matter; MODIS; Irish Sea.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00383/49473/49960.pdf

Optimisation de la surveillance des masses d’eau DCE en Méditerranée. Utilisation de produits dérivés d’images satellites en complément du réseau de mesures in-situ
Provedor de dados: 5
Autores: Ganzin, Nicolas; Mangin, Antoine.
This study aims at showing the potential of « water colour » data derived from satellite imagery to optimise the monitoring of coastal waters within the WFD, with the French Mediterranean as a study area. The work is focused on one specific parameter, the surface chlorophyll-A (chl-a) concentration of which a monthly atlas for reference to “normal” values is provided, which consists of : (i) the monthly chl-a median computed from satellite data of 2003, 2004 and 2005 ; (ii) the integration in space of these values, represented by their average over the WFD water masses (except those of very small size) ; (iii) an indicator of the spatial variability of the chl-a through the spatial standard deviation within each water mass. Another important result is the...
Tipo: Text
Palavras-chave: Chlorophylle; Imagerie satellite; Couleur de l’eau; MERIS; MODIS; Directive Cadre sur l’Eau; DCE; Méditerranée; Chlorophyll; Satellite imagery; Water colour; MERIS; MODIS; Water Frame Directive; WFD; Mediterranean.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/00398/50906/51677.pdf

Modeling Near-Surface Suspended Sediment Concentration in the English Channel
Provedor de dados: 5
Autores: Guillou, Nicolas; Rivier, Aurelie; Gohin, Francis; Chapalain, Georges.
The present study investigates the performances of the three-dimensional multicomponent hydro-sedimentary model ROMS (Regional Ocean Modeling System) to predict near-surface suspended sediment concentrations (SSC) in the English Channel (western Europe). Predictions are assessed against satellite-retrieved observations from raw MODIS and MERIS images for the year 2008 characterized by the highest availability of cloud-free data. Focus is put on improvements obtained with: (1) SSC inputs at the open boundaries; and (2) simple parameterizations of the settling velocity and the critical shear stress. Sensitivity studies confirm the importance of the advection of fine-grained suspended sediments in the central waters of the English Channel exhibiting benefits...
Tipo: Text
Palavras-chave: ROMS; Satellite; MERIS; MODIS; Tide; Wave.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00276/38766/37307.pdf

The impact of tides and waves on near-surface suspended sediment concentrations in the English Channel
Provedor de dados: 5
Autores: Guillou, Nicolas; Rivier, Aurelie; Chapalain, Georges; Gohin, Francis.
Numerous ecological problems of continental shelf ecosystems require a refined knowledge of the evolution of suspended sediment concentrations (SSC). The present investigation focuses on the spatial and temporal variabilities of near-surface SSC in coastal waters of the English Channel (western Europe) by exploiting numerical predictions from the Regional Ocean Modeling System ROMS. Extending previous investigations of ROMS performances in the Channel, this analysis refines, with increased spatial and temporal resolutions, the characterization of near-surface SSC patterns revealing areas where concentrations are highly correlated with evolutions of tides and waves. Significant tidal modulations of near-surface concentrations are thus found in the eastern...
Tipo: Text
Palavras-chave: Sediment transport; Numerical modeling; Satellite; ROMS; MERIS; MODIS.
Ano: 2017
URL: https://archimer.ifremer.fr/doc/00345/45607/45227.pdf

Multitemporal variables for the mapping of coffee cultivation areas
Provedor de dados: 86
Autores: Souza,Carolina Gusmão; Arantes,Tássia Borges; Carvalho,Luis Marcelo Tavares de; Aguiar,Polyanne.
Abstract: The objective of this work was to propose a new methodology for mapping coffee cropping areas that includes multitemporal data as input parameters in the classification process, by using the Landsat TM NDVI time series, together with an object-oriented classification approach. The algorithm BFAST was used to analyze coffee, pasture, and native vegetation temporal profiles, allied to a geographic object-based image analysis (GEOBIA) for mapping. The following multitemporal variables derived from the R package greenbrown were used for classification: mean, trend, and seasonality. The results showed that coffee, pasture, and native vegetation have different temporal behaviors, which corroborates the use of these data as input variables for mapping....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: BFAST; Classification; MODIS; NDVI; Remote sensing; R package greenbrown.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2019000103701

INVESTIGAÇÃO DO NDVI E REFLECTÂNCIA DAS BANDAS DO VERMELHO E INFRAVERMELHO-PRÓXIMO DE SENSORES DISTINTOS SIMULADOS POR MEIO DE DADOS DO HYPERION PARA CANA-DE-AÇÚCAR E FLORESTA NATURAL
Provedor de dados: 107
Autores: Pedro Quarto Júnior; UFES; Alexandre Cândido Xavier; UFES; Julião Soares de Souza Lima; UFES.
Este trabalho teve como objetivo analisar a inter-relação da reflectância das bandas do vermelho (Ver) e do infravermelho-próximo (IVP) e do Índice de Vegetação da Diferença Normalizada (NDVI) dos sensores multiespectrais MODIS (Moderate Resolution Imaging Spectroradiometer), ETM+ (Thematic Mapper Plus) e HRV (High Resolution Visible). Uma imagem hiperespectral do Hyperion foi adquirida sobre a região de Campos dos Goytacazes, Estado do Rio de Janeiro, tendo os efeitos atmosféricos corrigidos. A simulação das bandas foi realizada a partir de 210 e 50 amostras de dados de reflectância hiperespectral, coletadas da imagem Hyperion, em áreas de cana-de-açúcar e de floresta natural, respectivamente. De acordo com os resultados conclui-se: a) as relações entre...
Tipo: Artigo Avaliado por Pares
Palavras-chave: Engenharia Agrícola; Mecanização Agrícola sensoriamento remoto; Índice de vegetação; MODIS; ETM+; HRV.
Ano: 2008
URL: http://www.seer.ufv.br/seer/index.php/reveng/article/view/57

Agriculture, habitat loss and spatial patterns of human occupation in a biodiversity hotspot
Provedor de dados: 63
Autores: Diniz-Filho,José Alexandre Felizola; Oliveira,Guilherme de; Lobo,Fábio; Ferreira,Laerte Guimarães; Bini,Luis Mauricio; Rangel,Thiago Fernando Lopes Valle Brito.
The Cerrado biome, the second largest biome in Neotropical region, consists of a mosaic of different habitat types, ranging from open grasslands to dense woodlands and dry forests. An intensive recent occupation process has transformed it into the most important region for cattle ranching and intensive commodity crops in Brazil. In this study, a macroecological approach was used to evaluate broad-scale spatial patterns of habitat loss in the Brazilian Cerrado, applying a series of spatial autocorrelation and partial regression analyses to understand how the proportion of remaining natural habitats is correlated with socio-economic variables, expressing different dimensions of human occupation and climatic variation. On average, 59% of the area is occupied...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: MODIS; Brazilian Cerrado; Spatial autocorrelation.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162009000600007

Correlation maps to assess soybean yield from EVI data in Paraná State, Brazil
Provedor de dados: 63
Autores: Figueiredo,Gleyce Kelly Dantas Araújo; Brunsell,Nathaniel Allan; Higa,Breno Hiroyuki; Rocha,Jansle Vieira; Lamparelli,Rubens Augusto Camargo.
ABSTRACT Vegetation indices are widely used to monitor crop development and generally used as input data in models to forecast yield. The first step of this study consisted of using monthly Maximum Value Composites to create correlation maps using Enhanced Vegetation Index (EVI) from Moderate Resolution Imaging Spectroradiometer (MODIS) sensor mounted on Terra satellite and historical yield during the soybean crop cycle in Paraná State, Brazil, from 2000/2001 to 2010/2011. We compared the ability of forecasting crop yield based on correlation maps and crop specific masks. We ran a preliminary regression model to test its ability on yield estimation for four municipalities during the soybean growing season. A regression model was developed for both...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: MODIS; Crop yield forecasting; Vegetation indices.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162016000500462

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

Crop area estimate from original and simulated spatial resolution data and landscape metrics
Provedor de dados: 63
Autores: Soares,Dênis de Moura; Galvão,Lênio Soares; Formaggio,Antônio Roberto.
Images acquired at the same day by the ETM+/Landsat-7 (30 m of spatial resolution) and MODIS/Terra (250 m) sensors were used to estimate areas of three major crops (soybean, sugarcane, and corn) with different landscape patterns in Southeastern Brazil. Majority filtering of ETM + classification results was applied to describe the behavior of 15 selected landscape metrics at distinct simulated spatial resolutions (90, 150, 210 and 270 m). By using regression models, the performance of MODIS and derived metrics to predict adequately the crop area, considering ETM+ data as reference, were analyzed. Results showed that the MODIS instrument overestimated the areas of soybean (15%) and sugarcane (1%), and underestimated the area of corn (12%). Multiple...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: MODIS; Remote sensing; Regression; Soybean; Sugarcane.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162008000500003

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

La fracción evaporativa en diferentes regiones agrícolas y naturales del centro-noroeste de la Argentina
Provedor de dados: 114
Autores: Luna Toledo,E.S; Figuerola,P.I; Abril,E.G; Ravelo,A.C.
La fracción evaporativa (FE) permite cuantificar la porción de la energía disponible usada en el proceso de evapotranspiración. Se obtuvo la distribución espacial de la FE para cinco tipos de cobertura: árboles, cultivos, pastizales, arbustos y suelo desnudo de cinco ecorregiones del centro-noroeste de la Argentina, usando productos del sensor MODIS-TERRA. FE se calculó mediante el método triangular según la relación entre la fracción de la cobertura de suelo (Fr) y la temperatura de superficie (Ts). Ambas variables fueron correlacionadas para cada tipo de cobertura por ecorregión. Fr y Ts están inversamente asociadas, y diferentes coberturas por ecorregiones mostraron cambios en la pendiente de la recta entre ambas variables debido a cambios en el...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Fracción evaporativa; Ecorregiones; MODIS; Heterogeneidad.
Ano: 2013
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1668-298X2013000100002

Assigning dates and identifying areas affected by fires in Portugal based on MODIS data
Provedor de dados: 42
Autores: PANISSET,JESSICA; DACAMARA,CARLOS C.; LIBONATI,RENATA; PERES,LEONARDO F.; CALADO,TERESA J.; BARROS,ANA.
ABSTRACT An automated procedure is here presented that allows identifying and dating burned areas in Portugal using values of daily reflectance from near-infrared and middle-infrared bands, as obtained from the MODIS instrument. The algorithm detects persistent changes in monthly composites of the so-called (V,W) Burn-Sensitive Index and the day of maximum change in daily time series of W is in turn identified as the day of the burning event. The procedure is tested for 2005, the second worst fire season ever recorded in Portugal. Comparison between the obtained burned area map and the reference derived from Landsat imagery resulted in a Proportion Correct of 95.6%. Despite being applied only to the months of August and September, the algorithm is able to...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Burned area; MODIS; Portugal; Remote sensing.
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652017000401487

NDVI and meteorological data as indicators of the Pampa biome natural grasslands growth
Provedor de dados: 53
Autores: Fontana,Denise Cybis; Junges,Amanda Heemann; Bremm,Carolina; Schaparini,Laura Pigatto; Mengue,Vagner Paz; Wagner,Ana Paula Luz; Carvalho,Paulo.
ABSTRACT The present study aimed to characterize the dynamics of NDVI and meteorological conditions, relating both to the annual dynamics of biomass accumulation in natural pastures of the Pampa biome as a way of subsidizing growth modeling. Forage accumulation rate data from a long-term experiment, NDVI data from the MODIS images, and meteorological data measured at the surface were used. We verify that the agrometeorological element associated to the accumulation of forage in the natural grasslands is different according to the season, which is typical of the subtropical climate. Winter is the critical season for livestock production due to the lower forage accumulation rate and lower values of NDVI, conditioned by the decrease of solar radiation and air...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Biomass accumulation; ENSO; MODIS; Ground data.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052018000200404

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

Simple Air Temperature Estimation Method from MODIS Satellite Images on a Regional Scale
Provedor de dados: 117
Autores: Flores P,Fabiola; Lillo S,Mario.
Agricultural studies on a regional scale about water balance and evapotranspiration estimation, among others, require estimating air temperature (Ta) spatial variation since the generally low density of weather stations does not allow obtaining such data for a specific area. The aim of this study was to estimate air temperature through atmospheric profiles provided by the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor on a regional level. One of the present-day methodologies estimates Ta through vertical temperature profiles, which is why modifications to this methodology were proposed for zoning, surface elevation, and pressure/altitude ratios. By applying this new methodology, better Ta estimates were obtained by replacing the MODIS sensor...
Tipo: Journal article
Palavras-chave: MODIS; Atmospheric profile; Digital elevation model.
Ano: 2010
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392010000300011

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