370 resultados para Kriging


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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Pós-graduação em Agronomia (Ciência do Solo) - FCAV

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Pós-graduação em Biometria - IBB

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The State of Mato Grosso do Sul is in full growth of this sector, thus the concern about harvesting systems are being studied, and these systems may influence the weed community interference of weeds in the cane sugar. The integrated management tool attached to geostatistics is to avoid productivity losses due to weed interference. The objective of this work was to study the spatial variability of the seed bank of weeds depending on the system for collecting cane sugar (raw and burning). The experiment was conducted in the area of commercial cultivation of the plant ETH Bioenergy S/A Eldorado Unity. Soil samples were taken with auger layer from 0.00 to 0.40 m depth in both cropping systems. The experimental plot was composed by a mesh consisting of 50 points georeferenced with irregular distances. Soil samples were taken to the greenhouse for germination. The number of weed species was analyzed using descriptive statistics and geostatistical techniques. The seeds of B. pilosa, dicots, bitter grass, nutsedge, dayflower monocots and spatial dependence of the seed bank in the collection system with burning of cane sugar. For the system of harvest only the raw sedge species present spatial dependence of distribution in the seed bank. In the harvest green cane enable the mapping of these species through the kriging maps produced, spot applications of herbicides in integrated management of Cyperus rotundus.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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The objective of this study was to analyze different intensities of soil sampling for accuracy in geostatistical analysis and interpolation maps for precision agriculture in the sugarcane area. Soil samples were collected at two regular grids at a depth of 0.00 to 0.20m for granulometric analysis (area 1) and soil fertility (area 2). We compared soil sampling intensities: 208, 105, 58 and 24 points in Area 1 and 206, 102 and 53 points in Area 2. The data were submitted to descriptive analysis and geostatistics. The variograms constructed with 105 points didn't differ from variograms with 208 points, which doesn't occur for 58 and 24 points. The increase of sampling interval and reducing the number of points promote greater error in kriging. Samples with more than 100 points per area did not result in significant improvements in the error of kriging, or differed in the amount of fertilizer applied to the field.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Soil CO2 efflux is the primary source of CO2 emissions from terrestrial ecosystems to the atmosphere. The rates of this flux vary in time and space producing hot moments (sudden temporal high fluxes) and hot spots (spatially defined high fluxes), but these high reaction rates are rarely studied in conjunction with each other. We studied temporal and spatial variation of soil CO2 efflux in a water-limited Mediterranean ecosystem in Baja California, Mexico. Soil CO2 efflux increased 522% during a hot moment after rewetting of soils following dry summer months. Monthly precipitation was the primary driver of the seasonal trend of soil CO2 efflux (including the hot moment) and through changes in soil volumetric water content (VWC) it influenced the relationship between CO2 efflux and soil temperature. Geostatistical analyses showed that the spatial dependence of soil CO2 efflux changed between two contrasting seasons (dry and wet). During the dry season high soil VWC was associated with high soil CO2 efflux, and during the wet season the emergence of a hot spot of soil CO2 efflux was associated with higher root biomass and leaf area index. These results suggest that sampling designs should accommodate for changes in spatial dependence of measured variables. The spatio-temporal relationships identified in this study are arguably different from temperate ecosystems where the majority of soil CO2 efflux research has been done. This study provides evidence of the complexity of the mechanisms controlling the spatio-temporal variability of soil CO2 efflux in water-limited ecosystems. (C) 2014 Elsevier Ltd. All rights reserved.

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In order to to research, the region of Perau, base metal mineralization, Grupo Votorantim Metals conducted a soil sampling on targets predetermined holding its chemical analysis. These reviews have been provided by the company for this work was to evaluate the potential use of these data pedogeochemical multi-element for refinement of the work of geological mapping. We selected six targets: Varginha, Salvador, Guararema Taquara Lisa and Coffin of Mendes, in the municipalities of Adrianople, Cerro Azul and Tunas do Paraná, located in Vale do Ribeira (PR). Both have about 10 km2 and situated in the geological context of the Fold Belt Terrane and the Massif de Joinville. The main rock types are present metasedimentary rocks of low to medium grade metamorphic, interspersed the amphibolites ortoderivados, both belonging to the Complex Perau, gneisses and migmatitic Complex. Applied to the geochemical data descriptive statistical techniques (variogram, kriging and histogram). From the correlation between the distributions of elements with the geological data, we could assess the potential of the proposed methodology.

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The Guaraní aquifer has relevant importance both as a source of water for several urban centres and the development of agriculture and livestock. In recharge areas the aquifer is free and, therefore, subject to contamination of effluents and tailings deposited on soils that cover it. Thus, it becomes crucial not only its protection at all levels, as the knowledge of its degree of natural vulnerability. The present work used geostatistics modeling techniques to study the natural vulnerability of the Guaraní aquifer in the city of Rio Bonito, State of São Paulo, southeastern Brazil, where the Guarani aquifer is exposed. These techniques, extensively used in evaluation studies of mineral deposits and oil tanks, can be adapted to produce a spatial classification or a regionalisation of probabilistic indices of vulnerability. By ordinary kriging method maps of vulnerability classification were obtained. To determine the vulnerability of the aquifer was employed the Aquifer Vulnerability Index (AVI), which requires knowledge of unsaturated zone thickness and permeability. The final product was a map with probabilistic index of vulnerability of the Guaraní aquifer, which presented values between 0 to 0.33 years, framing the area studied in AVI class extremely high vulnerability

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Classical statistical techniques which necessarily assume that all sampling units are random and independent were always used in the timber industry. Geostatistics considers that certain phenomena are characterized by spatial dependence: values of sampling units closer to each other tend to be more similar than values of sampling units farther away. This study aimed to characterize the spatial variability of the finishing (dyer) in the upper and lower surfaces of four edge glued panels by using geostatistical methods using geoR. Semivariograms were constructed for the analysis of spatial dependence. The spherical mathematical model was the best fit to the semivariograms generated, and was done the interpolation of the data (kriging) in samples where the distribution of dyer presents spatial dependence. In the bottom surfaces of two panels where the spatial dependence was detected geostatistical methods characterized a very large spatial variability due to the heterogeneous application of the finishing