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| Registros recuperados: 159 | |
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| Seidel,Enio Júnior; Oliveira,Marcelo Silva de. |
| ABSTRACT: In geostatistical studies, spatial dependence can generally be described by means of the semivariogram or, in complementary form, with a single index followed by its categorization to classify the degree of such dependence. The objective of this study was to construct a categorization for the spatial dependence index (SDI) proposed by Seidel and Oliveira (2014) in order to classify spatial variability in terms of weak, moderate, and strong dependence. Theoretical values were constructed from different degrees of spatial dependence, which served as a basis for calculation of the SDI. In view of the form of distribution and SDI descriptive measures, we developed a categorization for posterior classification of spatial dependence, specific to each... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Geostatistics; Spatial dependence; Spatial variability; Semivariogram; Summary measures. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832016000100313 |
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| Doray, Mathieu; Petitgas, Pierre; Josse, E. |
| Universal kriging was used to model the spatio-temporal variability in the acoustic density of tuna aggregations recorded during star echosounding surveys around moored fish aggregating devices (FADs) in Martinique (Lesser Antilles). The large-scale deterministic drift in the tuna spatial distribution was modeled using an advection-diffusion equation applied to animal grouping. Residuals from the drift were modeled as a random component with small-scale spatial correlation. An estimation variance formula was derived from this deterministic-statistical mixed model to assess the mean precision of density estimates of daytime tuna aggregation. The mean relative error obtained with our star design for daytime surveys was 24%. The methodology was applied to... |
| Tipo: Text |
Palavras-chave: Acoustic survey precision; Advection diffusion model; Moored fish aggregating devices; Tuna; Geostatistics. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4559.pdf |
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| BASSOI, L. H.; MIELE, A.; REISSER JUNIOR, C.; GEBLER, L.; FLORES, C. A.; FILIPPINI ALBA, J. M.; GREGO, C. R.; TERRA, V. S. S.; TIMM, L. C.; NASCIMENTO, P. dos S.. |
| Os sistemas de produção atualmente existentes na fruticultura brasileira caracterizam-se pela execução de diversas práticas agrícolas durante o ciclo da cultura, tendo como preocupação a quantidade e a qualidade da produção, e a rentabilidade da atividade agrícola. Nesse contexto, cria-se uma oportunidade para a aplicação de agricultura de precisão, como forma de auxiliar a gestão do sistema de produção e a tomada de decisão pelo produtor. Nesse capítulo, são apresentados quatro estudos de caso em que a realização de procedimentos e o uso de ferramentas, característicos de agricultura de precisão, permitem aos produtores e técnicos a compreensão da variabilidade de atributos do solo e da planta e de suas relações, bem como o estabelecimento de zonas... |
| Tipo: Capítulo em livro técnico (INFOTECA-E) |
Palavras-chave: Geoestatística; Análise multivariada; Agricultura de precisao; Fruticultura; Viticultura; Estatística agrícola; Método estatístico; Maçã; Pêssego; Uva; Precision agriculture; Fruit growing; Viticulture; Geostatistics; Agricultural statistics; Multivariate analysis. |
| Ano: 2014 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/1008274 |
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| Chiba,Marcio Koiti; Vieira,Sidney Rosa; González,Antonio Paz; Dechen,Sonia Carmela Falci; Maria,Isabella Clerici de. |
| This study was carried out in order to assess the spatial variability of some soil properties after adoption of no tillage system (NTS). A 19,200 m² plot was marked with a 20 x 20 m spacing grid. Crop yield and soil attributes, at 0-0.2 m deep layer, were measured in 63 points in 1985, 1987 and 1988. The spatial variability was assessed by semivariogram calculation using geostatistics. Soil base saturation index (BS) was interpolated by kriging and also, using a bivariate geostatistical method, the collocated cokriging (CLCK) using terrain elevation as ancillary data. Although, the coefficient of variation (Cv) for soil organic matter content decreased from 1985 (20.4%) to 1988 (10.7%), its mean value increased 32% in the same period. The soil fertility in... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Geostatistics; Kriging; Cokriging. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052010000500005 |
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| GREGO, C. R.; PAIM, F. A. de P.; RODRIGUES, C. A. G.; CRISCUOLO, C.; GARCON, E. A. M.; MANJOLIN, R. C.; ALVAREZ, I. A.; ALBUQUERQUE, T. C. S. de. |
| Este trabalho tem como objetivo o uso da análise geoestatística no mapeamento da fertilidade do solo de seis propriedades familiares do Circuito das Frutas, localizadas nos municípios de Itatiba, Atibaia, Jundiaí, Valinhos, Indaiatuba, Jarinú, no estado de São Paulo. |
| Tipo: Boletim de Pesquisa e Desenvolvimento (INFOTECA-E) |
Palavras-chave: Geoestatística; Variabilidade espacial; Krigagem ordinária; Culturas frutíferas; Spatial variability; Ordinary kriging; Fruticultura; Fertilidade do Solo; Geostatistics; Fruit crops. |
| Ano: 2018 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/1102129 |
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| NASCIMENTO, P. S.; SILVA, J. A.; COSTA, B. R. S.; BASSOI, L. H.. |
| A otimização na aplicação dos recursos hídricos constitui uma das preocupações da agricultura irrigada. Nesse sentido, esta pesquisa foi desenvolvida com o objetivo de aplicar o conceito de zonas homogêneas do solo para a realização do manejo diferenciado da irrigação em um pomar de videira. O experimento foi conduzido em área de produção comercial, localizada no Perímetro Irrigado Senador Nilo Coelho, em Petrolina-PE. Foi selecionada uma área com 40 fileiras de plantas e 82 plantas por fileira, em um pomar de videira cultivar Thompson Seedless sobre o porta-enxerto SO4, com 1 difusor por planta e conduzida no sistema de latada. Amostras de solo foram coletadas nas profundidades de 0,0-0,2 e 0,2-0,4 m para a determinação da curva de retenção de água no... |
| Tipo: Capítulo em livro técnico (INFOTECA-E) |
Palavras-chave: Vale do São Francisco; Available soil water; Spatial dependence; Uva; Irrigação; Manejo; Vitis Vinifera; Grapes; Geostatistics. |
| Ano: 2014 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/1008326 |
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| Corrêa,Adriany Rodrigues; Montanari,Rafael; Laura,Valdemir Antônio; Melotto,Alex Marcel; Silva,Evelize Nayara Santana da; Pellin,Douglas Martins Pereira; Santos,Anderson Secco dos. |
| In Brazil, grazing mismanagement may lead to soil and pasture degradation. To impede this process, integrated cropping systems such as silvopasture have been an effective alternative, allied with precision agriculture based on soil mapping for site-specific management. In this study, we aimed to define the soil property that best sheds light on the variability of eucalyptus and forage yield. The experiment was conducted in the 2011/12 crop year in Ribas do Rio Pardo, Mato Grosso do Sul State, Brazil. We analyzed linear and spatial correlations between eucalyptus traits and physical properties of a Typic Quartzipsamment at two depths (0.00-0.10 and 0.10-0.20 m). For that purpose, we set up a geostatistical grid for collection at 72 points. Gravimetric... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Geostatistics; Resistance to penetration; Soil management; Agricultural sustainability. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832015000200438 |
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| Oliveira,Mara Lucia Jacinto; Valladares,Gustavo Souza; Vieira,Johnston Silva; Coelho,Ricardo Marques. |
| ABSTRACT The aim of the present work was to: (i) determine and map the micronutrient content (copper - Cu, iron - Fe, manganese - Mn and zinc - Zn) in soils of the State of Ceará; (ii) evaluate soil attributes related to micronutrient availability; and (iii) evaluate, by ordinary kriging, the spatial dependence of the micronutrient content. The study area is located in the central region of Ceará, in the basin of the River Banabuiú. Soil samples were collected in the surface and subsurface layers to determine the chemical attributes, granulometry, and micronutrient content, extracted with Mehlich-1 solution. The sites of the principal types of soil in the region were spatialised and the results submitted to descriptive analysis and Pearson correlation... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cationic micronutrients; Geostatistics; Ordinary kriging; Soils of the semi-arid region. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902018000300371 |
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| 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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| Leal,Fábio Tiraboschi; França,Ana Beatriz Coelho; Siqueira,Diego Silva; Teixeira,Daniel De Bortoli; Marques Júnior,José; Scala Júnior,Newton La. |
| ABSTRACTSoil CO2 emissions (fCO2) in agricultural areas have been widely studied in global climate change research, but its characterization and quantification are restricted to small areas. Because spatial and time variability affect emissions, tools need to be developed to predict fCO2 for large areas. This study aimed to investigate soil magnetic susceptibility (MS) and its correlation with fCO2 in an agricultural environment. The experiment was carried out on a Typic Eutrudox located in Guariba-SP, Brazil. Results showed that there was negative spatial correlation between fCO2 and the magnetic susceptibility of Air Dried Soil (MSADS) up to 34.3 m distant. However, the fCO2 had no significant correlation with MSADS, magnetic susceptibility of sand... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Magnetism; Soil respiration; Spatial variability; Geostatistics. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162015000600535 |
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| Bastiani,Fernanda de; Uribe-Opazo,Miguel A.; Dalposso,Gustavo H.. |
| A study about the spatial variability of data of soil resistance to penetration (RSP) was conducted at layers 0.0-0.1 m, 0.1-0.2 m and 0.2-0.3 m depth, using the statistical methods in univariate forms, i.e., using traditional geostatistics, forming thematic maps by ordinary kriging for each layer of the study. It was analyzed the RSP in layer 0.2-0.3 m depth through a spatial linear model (SLM), which considered the layers 0.0-0.1 m and 0.1-0.2 m in depth as covariable, obtaining an estimation model and a thematic map by universal kriging. The thematic maps of the RSP at layer 0.2-0.3 m depth, constructed by both methods, were compared using measures of accuracy obtained from the construction of the matrix of errors and confusion matrix. There are... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Geostatistics; Maximum likelihood; Error matrix. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162012000200019 |
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| Registros recuperados: 159 | |
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