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CHANGE DETECTION IN BRAZILIAN SAVANNAS USING SEMIVARIOGRAMS DERIVED FROM NDVI IMAGES Ciência e Agrotecnologia
Acerbi Júnior,Fausto Weimar; Silveira,Eduarda Martiniano de Oliveira; Mello,José Márcio de; Mello,Carlos Rogério de; Scolforo,José Roberto Soares.
The Normalized Difference Vegetation Index (NDVI) is often used to extract information from vegetated areas since it is directly related to vegetation parameters such as percent of ground cover, photosynthetic activity of the plant and leaf area index. The aim of this paper was to analyze the potencial of semivariograms generated from NDVI values to detect changes in vegetated areas, analyzing their behavior (shape) and derived metrics (range, sill and nugget). Semivariograms were generated from NDVI values derived from Landsat TM images of May 2010, June 2010 and July 2011. The study area is located in the northern state of Minas Gerais, Brazil, and is covered by Brazilian savannas vegetation, totalizing 1,596 ha. Semivariograms were generated after the...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Deforestation; Geostatistics; Remote sensing.
Ano: 2015 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542015000200103
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Estratificação de um povoamento de eucalipto por interpoladores geoestatísticos e sensoriamento remoto PAB
Reis,Aliny Aparecida dos; Mello,José Márcio de; Raimundo,Marcel Régis; Acerbi Júnior,Fausto Weimar; Oliveira,Marcelo Silva de; Diniz,Juliana Maria Ferreira de Souza.
Resumo: O objetivo deste trabalho foi avaliar a utilização de interpoladores geoestatísticos e imagens de sensoriamento remoto, para a estratificação de povoamentos de Eucalyptus sp. em idade de corte. As estimativas da amostragem casual estratificada foram comparadas às estimativas da amostragem sistemática quanto à variável volume de madeira. A área de estudo correspondeu a um povoamento clonal de Eucalyptus sp. no Município de Lagoa Grande, MG. O inventário florestal foi realizado em 2011, em quatro situações de amostragem e diferentes números de parcelas. A estratificação da área foi feita por meio de krigagem da área basal (variável principal), da reflectância na banda TM5 (variável auxiliar) obtida em uma imagem Landsat 5 TM e com base na cokrigagem...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Eucalyptus; Cokrigagem; Imagens; Inventário florestal; Krigagem.
Ano: 2016 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2016001001751
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Influence of diameter measuring height on the adjustment of volume and biomass equations of cerrado in minas gerais Ciência e Agrotecnologia
Morais,Vinícius Augusto; Mello,José Márcio de; Gomide,Lucas Rezende; Scolforo,José Roberto Soares; Araújo,Emanuel José Gomes de; Rufini,Ana Luiza.
Different tree diameter measuring heights are displayed in the literature, which in some cases can lead to different results in the final estimates, if the model used is not compatible with the diameter measurement height. The aim of this study was to evaluate and validate equations of volume and biomass, adjusted by Goal Programming and regression by Ordinary Least Squares Method for the Cerrado Sensu Stricto and Campo Cerrado in Minas Gerais state, using information on diameters measured at 0. 10, 0.30 and 1.30 meters from the ground level. Thus, we rigorously scaled 868 trees in areas of Cerrado Sensu Stricto and Campo Cerrado of Minas Gerais. Two different models were subsequently adjusted, one being dual input with the diameter measured at different...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Regression models; Forest inventory Brazilian; Savannas.
Ano: 2014 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542014000300002
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Modeling growth and yield of loblolly pinestands under intensive management PAB
Ferraz Filho,Antonio Carlos; Scolforo,José Roberto Soares; Oliveira,Antonio Donizette de; Mello,José Márcio de.
Abstract:The objective of this work was to develop and validate a prognosis system for volume yield and basal area of intensively managed loblolly pine (Pinus taeda) stands, using stand and diameter class models compatible in basal area estimates. The data used in the study were obtained from plantations located in northern Uruguay. For model validation without data loss, a three-phase validation scheme was applied: first, the equations were fitted without the validation database; then, model validation was carried out; and, finally, the database was regrouped to recalibrate the parameter values. After the validation and final parameterization of the models, a simulation of the first commercial thinning was carried out. The developed prognosis system was...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Pinus taeda; Model validation; Prognosis system; Pruning; Sawtimber; Thinning.
Ano: 2015 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2015000800707
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Object-based change detection using semivariogram indices derived from NDVI images: The environmental disaster in Mariana, Brazil Ciência e Agrotecnologia
Silveira,Eduarda Martiniano de Oliveira; Acerbi Júnior,Fausto Weimar; Mello,José Márcio de; Bueno,Inácio Thomaz.
ABSTRACT Object-based change detection is a powerful analysis tool for remote sensing data, but few studies consider the potential of temporal semivariogram indices for mapping land-cover changes using object-based approaches. In this study, we explored and evaluated the performance of semivariogram indices calculated from remote sensing imagery, using the Normalized Differential Vegetation Index (NDVI) to detect changes in spatial features related to land cover caused by a disastrous 2015 dam failure in Brazil’s Mariana district. We calculated the NDVI from Landsat 8 images acquired before and after the disaster, then created objects by multiresolution segmentation analysis based on post-disaster images. Experimental semivariograms were computed within...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Remote sensing; Geostatistics; Feature extraction.
Ano: 2017 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542017000500554
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Padrão espaço-temporal da umidade volumétrica do solo em uma bacia hidrográfica com predominância de latossolos Rev. Bras. Ciênc. Solo
Ávila,Léo Fernandes; Mello,Carlos Rogério de; Mello,José Márcio de; Silva,Antônio Marciano da.
A umidade volumétrica do solo possui alta variabilidade espacial e temporal devido à influência de vários fatores ambientais e de uso do solo. Desse modo, seu entendimento assume papel fundamental na modelagem dos processos que envolvem o escoamento superficial, a erosão do solo e o transporte de sedimentos. Nesse contexto, objetivou-se neste estudo avaliar o padrão espacial e temporal da umidade volumétrica na camada superficial do solo, nas diferentes estações do ano, em uma bacia hidrográfica experimental, com predominância de latossolos, localizada na região Sul de Minas Gerais. Para isso, utilizou-se o conceito de estabilidade temporal e escalonamento de semivariogramas, o qual possibilitou a comparação da estrutura espacial dos modelos de...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Estabilidade temporal; Estrutura da variabilidade espacial; Semivariograma; Umidade do solo.
Ano: 2011 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832011000500034
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Spatial distribution of top soil water content in an experimental catchment of Southeast Brazil Scientia Agricola
Mello,Carlos Rogério de; Ávila,Léo Fernandes; Norton,Lloyd Darrell; Silva,Antônio Marciano da; Mello,José Márcio de; Beskow,Samuel.
Soil water content is essential to understand the hydrological cycle. It controls the surface runoff generation, water infiltration, soil evaporation and plant transpiration. This work aims to analyze the spatial distribution of top soil water content and to characterize the spatial mean and standard deviation of top soil water content over time in an experimental catchment located in the Mantiqueira Range region, state of Minas Gerais, Brazil. Measurements of top soil water content were carried out every 15 days, between May/2007 and May/2008. Using time-domain reflectometry (TDR) equipment, 69 points were sampled in the top 0.2 m of the soil profile. Geostatistical procedures were applied in all steps of the study. First, the spatial continuity was...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Mantiqueira Range; Soil water content mapping; Soil hydrology; Geostatistical techniques.
Ano: 2011 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162011000300003
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Species richness and diversity in shrub savanna using ordinary kriging PAB
Batista,Anderson Pedro Bernardina; Mello,José Márcio de; Raimundo,Marcel Régis; Scolforo,Henrique Ferraço; Reis,Aliny Aparecida dos; Scolforo,José Roberto Soares.
Abstract: The objective of this work was to analyze the spatial distribution and the behavior of species richness and diversity in a shrub savanna fragment, in 2003 and 2014, using ordinary kriging, in the state of Minas Gerais, Brazil. In both evaluation years, the measurements were performed in a fragment with 236.85 hectares, in which individual trees were measured and identified across 40 plots (1,000 m2). Species richness was determined by the total number of species in each plot, and diversity by the Shannon diversity index. For the variogram study, spatial models were fitted and selected. Then, ordinary kriging was applied and the spatial distribution of the assessed variables was described. A strong spatial dependence was observed between species...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Geostatistics; Shannon index; Variogram.
Ano: 2016 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2016000800958
Registros recuperados: 8
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