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Avaliação do desempenho de um modelo de estimativa de saldo de radiação em algumas culturas. Repositório Alice
ACOSTA, J. F.; CARDOZO, N. P.; MARIN, F. R..
Avaliou-se o desempenho do método de estimativa do saldo de radiação proposto por ALLEN, 1998, em experimentos de culturas de girassol, amendoim, café, limão e grama, através de regressões lineares com base nos indicadores estatísticos coeficiente de correlação r?, índice de Willmott ?d? e índice de desempenho ?c?. Segundo os critérios de avaliação do índice ?c?, o método proposto por ALLEN, 1998 representa de forma satisfatória os dados de saldo de radiação, sendo obtidos os desempenhos equivalentes a 0,79 (muito bom) para as culturas de girassol e grama e de 0,96; 0,86 e 0,88 (ótimo) para as culturas de amendoim, café e limão, respectivamente.
Tipo: Anais e Proceedings de eventos Palavras-chave: Saldo de radiação; Índice de Willmott “d”; Índice de desempenho “c”; Coeficiente de correlação “r”; Modelagem; Indicadores estatísticos; Modelling; Willmott index.; Net radiation.
Ano: 2009 URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/513474
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Calibração e validação do modelo SEBAL para as condições semi-áridas do Nordeste brasileiro. Repositório Alice
TEIXEIRA, A. H. de C.; BASTIAANSSEN, W. G. M..
A precisão na determinação da evapotranspiração atual(ET)reduz significativamente incertezas no balanço hídrico de uma bacia hidrográfica. Medidasde ET em áreas de parreirais, pomar de manga e vegetação natural (caatinga) foram feitas no sub médio São Francisco. Métodos micro meteorológicos foram usados que fornecem valores pontuais para locais específicos (Teixeiraetal.,2007,2008a,b) .As extrapolações diretas de dados pontuais para escala regional podem conduzir erros nas estimativas de ET,porque medidas locais defluxos não podem fornecer uma amostragem precisa para um aárea maior(Wylieetal.,2003). Um dos algoritmos usados para estimativa daETem escala regional por sensoriamento remoto é o Surface Energy Balance Algorithm for Land SEBAL...
Tipo: Parte de livro Palavras-chave: Fluxo de calor latente; Calor sensível; Calor no solo; SEBAL; Calibração; Nordeste Vale do São Francisco; Evaporative fraction; Evapotran spiration; Net radiation; Soil heat flux.; Clima; Evapotranspiração; Balanço Hídrico; Radiação; Sensoriamento Remoto..
Ano: 2009 URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/161997
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Energy balance in the watershed of Ipê, Northwestern São Paulo State, Brazil. Repositório Alice
FEITOSA, D. G.; HERNANDEZ, F. B. T.; FRANCO, R. A. M.; TEIXEIRA, A. H. de C.; NEALE, C. M..
The aim of this paper was to assess someparameters related to the energy balance of Ipês watershed, that changed since no sugarcane cultivation in 2006 to 2.164 hectares in 2011, occupying 31% of the catchment area with this important energy crop For the economy and the environment of Brazil.
Tipo: Artigo de periódico Palavras-chave: Sugar cane; Net radiation; Latent heat flux; Sensible heat flux; Radiação líquida; Fluxo de calor latente; Fluxo de calor sensível.; Cana de Açúcar..
Ano: 2016 URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1059731
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Energy balance partitioning and evapotranspiration from irrigated Muskmelon under Semi-Arid Conditions Bragantia
Vanomark,Giuliana Mairana Morais de Sousa; Espínola Sobrinho,José; Bezerra,José Renato Cortez; Santos,Carlos Antonio Costa dos; Azevedo,Pedro Vieira de; Silva,Saulo Tasso Araújo da; Bezerra,Bergson Guedes.
ABSTRACT The Mossoró-Assu-Baraúna district, Rio Grande do Norte State (RN), is recognized by the intense production of horticulture, mainly muskmelon for export. However, this region is often devastated by intense droughts. Thus, the muskmelon production is predominantly under irrigated condition and, due to constant threat of water resources collapse on the region, a rigorous irrigation water management in the region is needed. The main objective of this article was to analyze the seasonal pattern of energy balance partitioning and evapotranspiration on irrigated muskmelon crop on the region around Mossoró-RN. The study was carried out in two areas of commercial production of muskmelons in the Mossoró-Assu-Barúna district, during two growth seasons from...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Mossoró-Assu-Baraúna district; Net radiation; Latent and sensible heat fluxes; Soil heat flux.
Ano: 2018 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052018000100168
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Energy balance with Landsat images in irrigated central pivots with corn crop in the São Paulo State, Brazil. Repositório Alice
TEIXEIRA, A. H. de C.; HERNANDEZ, F. B. T.; ANDRADE, R. G.; LEIVAS, J. F.; BOLFE, E. L..
The energy balance (EB) components were quantified in a commercial farm with corn crop, irrigated by central pivots, in the Northwestern side of São Paulo state, Southeast Brazil. The SAFER (Simple Algorithm For Evapotranspiration Retrieving) was applied to retrieve the latent heat flux (λE), considering six pivots, covering irrigated areas from 74 to 108 ha. With λE quantified and considering soil heat flux (G) as a fraction of net radiation (Rn), the sensible heat flux (H) was acquired as a residual in the energy balance equation. Seven Landsat satellite images, covering all corn crop stages from 23 April 2010 to 29 August 2010, allowed relating the energy balance components according to the accumulated degree-days (DDac) from the...
Tipo: Artigo de periódico Palavras-chave: Latent heat flux; Soil heat flux.; Sensible heat flux; Net radiation.
Ano: 2014 URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1001276
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Energy balances in sugar cane, coffee and natural vegetation in the northeastern side of the São Paulo state, Brazil Repositório Alice
TEIXEIRA, A. H. de C.; LEIVAS, J. F.; RONQUIM, C. C.; SILVA, G. B. S. da; VICTORIA, D. de C..
Under land and climate change scenarios, agriculture has experienced water competitions among other sectors in the São Paulo state, Brazil. On the one hand, in several occasions, in the northeastern side of this state, nowadays sugar-cane is expanding, while coffee plantations are losing space. On the other hand, both crops have replaced the natural vegetation composed by Savannah and Atlantic Coastal Forest species. Under this dynamic situation, geosciences are valuable tools for evaluating the large-scale energy and mass exchanges between these diffe rent agro-ecosystems and the lower atmosphere. For quantification of the energy balance components in these mixed agro-ecosystems, the bands 1 and 2 from the MODIS product MOD13Q1 we re used throughout SA...
Tipo: Artigo de periódico Palavras-chave: Net radiation; Latent heat flux; Sensible heat flux; Agro-ecosystems; Saldo de radiação; Fluxo de calor latente; Fluxo de calor sensível; Agro-ecossistemas.; Sensoriamento Remoto.; Remote sensing..
Ano: 2016 URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1055656
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Evaluation of the Water Requirements for a Greenhouse Tomato Crop using the Priestley-Taylor Method Chilean J. Agric. Res.
Valdés-Gómez,Héctor; Ortega-Farías,Samuel; Argote,Mauricio.
The Priestley-Taylor (PT) model was evaluated for estimating the real evapotranspiration (ETreal) of a drip-irrigated greenhouse tomato (Lycopersicon esculentum Mill.) crop. The net radiation incorporated in the PT model was estimated using meteorological variables. For this experiment, an automatic weather station (AWS) was installed inside the greenhouse to measure solar radiation (Rgi), net radiation (Rn), air temperature (Ta) and relative humidity (RH). Another AWS was installed over a grass cover to measure atmospheric conditions outside the greenhouse. The experiment was carried out at the Panguilemo experimental station (35°23' S, 71°40' W, 110 m.a.s.l.) from August to December 2000. The PT model was evaluated using the ETreal obtained from the...
Tipo: Journal article Palavras-chave: Irrigation; Model; Crop coefficients; Net radiation; Soil heat flu.
Ano: 2009 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392009000100001
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Large-scale radiation and energy balances with Landsat 8 images and agrometeorological data in the Brazilian semiarid region. Repositório Alice
TEIXEIRA, A. H. de C.; LEIVAS, J. F.; HERNANDEZ, F. B. T.; FRANCO, R. A. M..
Aiming to subsidize the rational water resources management, four Landsat 8 (L8) images along different conditions of the year 2014 were used for modeling the radiation and energy balances in the mixed agroecosystems inside a Brazilian reference semiarid area. The SAFER algorithm was applied to calculate the latent heat flux (λE); net radiation (Rn) was acquired by the Slob equation; ground heat flux (G) was considered a fraction of Rn; and the sensible heat flux (H) was retrieved by residue in the energy balance equation. For classifying the vegetation, the surface resistance algorithm (SUREAL) was used to estimate the surface resistance to the water fluxes (rs) with threshold values for rs. Clearly, one could see higher λE values from...
Tipo: Artigo de periódico Palavras-chave: Energy partition; Latent heat flux; Net radiation; Sensible heat flux; Soil heat flux..
Ano: 2017 URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1073988
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Large-scale water productivity assessments with MODIS images in a changing semi-arid environment: a Brazilian case study. Repositório Alice
TEIXEIRA, A. H. de C.; SCHERER-WARREN, M.; HERNANDEZ, F. B. T.; ANDRADE, R. G.; LEIVAS, J. F..
In the Brazilian semi-arid region, the intensification of agriculture results in a change of natural vegetation by irrigated crops. To quantify the contrast between these two ecosystems, the large-scale values of water productivity components were modelled in Petrolina (PE) and Juazeiro (BA) municipalities. The SAFER (Simple Algorithm For Evapotranspiration Retrieving) algorithm was used to acquire evapotranspiration (ET), while the Monteith's radiation model was applied for estimating the biomass production (BIO). Moderate Resolution Imaging Spectroradiometer (MODIS) satellite images were used together with agro-meteorological data. In Petrolina and Juazeiro, the mean monthly ET values for irrigated crops were 938 and 739 mm·month−1, with the...
Tipo: Artigo de periódico Palavras-chave: Net radiation; Surface resistance.; Evapotranspiration; Biomass production..
Ano: 2013 URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/971815
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Procedures for calculation of the albedo with OLI-Landsat 8 images: Application to the Brazilian semi-arid AGRIAMBI
Silva,Bernardo B. da; Braga,Alexandra C.; Braga,Célia C.; Oliveira,Leidjane M. M. de; Montenegro,Suzana M. G. L.; Barbosa Junior,Bernardo.
ABSTRACT The surface albedo plays an important role in the exchanges of energy and mass in the planetary boundary layer. Therefore, changes in albedo affect the balance of radiation and energy at the surface, which can be detected with its monitoring. Albedo determination has been performed through various sensors, but there is not yet any publication dealing with albedo calculation procedures using OLI (Operational Land Imager) - Landsat 8 images. The objective of the study is to present the procedures for computing the albedo with OLI images and map it in irrigated areas of the São Gonçalo Irrigated District, PB, Brazil. Images of the year 2013, path 215 and row 65, were selected. The data necessary for calculating the albedo were extracted from each...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Radiance; Spectral reflectance; Atmospheric transmittance; Net radiation.
Ano: 2016 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662016000100003
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Radiation and energy balance of lettuce culture inside a polyethylene greenhouse PAB
Frisina,Valéria de Almeida; Escobedo,João Francisco.
The objective of this paper was to describe the radiation and energy balance, during the lettuce (Lactuca sativa, L. cv. Verônica) crop cycle inside a polyethylene greenhouse. The radiation and energy balance was made inside a tunnel greenhouse with polyethylene cover (100 mum) and in an external area, both areas with 35 m². Global, reflected and net radiation, soil heat flux and air temperature (dry and humid) were measured during the crop cycle. A Datalogger, which operated at 1 Hz frequency, storing 5 minutes averages was utilized. The global (K<FONT FACE=Symbol>¯</FONT>) and reflected (K<FONT FACE=Symbol>­</FONT>) radiations showed that the average transmission of global radiation (K<FONT FACE=Symbol>¯</FONT>in /...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Global radiation; Reflected radiation; Net radiation; Heat fluxes.
Ano: 1999 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X1999001000003
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Radiation balance of coffee hedgerows AGRIAMBI
Angelocci,Luiz R.; Marin,Fábio R.; Pilau,Felipe G.; Righi,Evandro Z.; Favarin,José L..
The radiation balance of hedgerows is an important variable in studies of mass and energy exchanges between parcial ground cover crops and the atmosphere. This paper describes a device with eight net radiometers encompassing the plants of a hedgerow. The radiometers were moved along a length of hedgerow, in a continuous and reversible movement. The canopy net radiation in this length (Rnc) was found by integration of the measurements over the notional cylinder formed. The device showed good performance and provided reliable measurements of Rnc of coffee hedgerows, showing itselfto be an useful technique of measurement in field conditions. Good correlations between Rnc and global solar radiation, turfgrass and coffee crop net radiation were found in 15-min,...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Correlation; Instrumentation; Solar radiation; Net radiation.
Ano: 2008 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662008000300008
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Silvopastoral system with Eucalyptus as a strategy for mitigating the effects of climate change on Brazilian pasturelands. Repositório Alice
BOSI, C.; PEZZOPANE, J. R. M.; SENTELHAS, P. C..
The aim of the present study was to assess the effect of Eucalyptus trees in a silvopastoral system on the microclimate and the capacity of that to mitigate the effects of climate change on pasturelands. This study included an open pasture of Piatã palisadegrass and an adjacent pasture that contained both palisadegrass and Eastto-West rows of Eucalyptus trees, with 15 m between rows, 2 m between trees within rows. The micrometeorological measurements were collected at several distances from the tree rows and in the open pasture. The silvopastoral system was associated with greater between-row shading when solar declination was high and greater near-tree shading when solar declination was around -22°. Both soil heat fl ux and temperature were infl uenced by...
Tipo: Artigo de periódico Palavras-chave: Net radiation; Shading; Soil heat flux; Agroforestry; Microclimate; Windbreaks.
Ano: 2020 URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1126754
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Silvopastoral system with Eucalyptus as a strategy for mitigating the effects of climate change on Brazilian pasturelands Anais da ABC (AABC)
BOSI,CRISTIAM; PEZZOPANE,JOSÉ RICARDO M.; SENTELHAS,PAULO CESAR.
Abstract The aim of the present study was to assess the effect of Eucalyptus trees in a silvopastoral system on the microclimate and the capacity of that to mitigate the effects of climate change on pasturelands. This study included an open pasture of Piatã palisadegrass and an adjacent pasture that contained both palisadegrass and East-to-West rows of Eucalyptus trees, with 15 m between rows, 2 m between trees within rows. The micrometeorological measurements were collected at several distances from the tree rows and in the open pasture. The silvopastoral system was associated with greater between-row shading when solar declination was high and greater near-tree shading when solar declination was around -22°. Both soil heat flux and temperature were...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Agroforestry; Microclimate; Net radiation; Shading; Soil heat flux; Windbreak.
Ano: 2020 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652020000201001
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Sugar cane energy and water balance by remote sensing in the São Paulo State, Braziil. Repositório Alice
TEIXEIRA, A. H. de C.; ANDRADE, R. G.; LEIVAS, J. F.; RONQUIM, C. C.; VICTORIA, D. de C.; HERNANDEZ, F. B. T..
A porção nordeste do Estado de São Paulo destaca-se pelas grandes áreas cultivadas com cana-de-açúcar. Considerando estas mudanças de uso da terra, um produto MODIS foi usado em conjunto com dados agrometeorológicas para a quantificação dos componentes dos balanços de energia e de água, ao longo do ano de 2012. Dois tipos de manejo foram considerados, colheita da cana com e sem queima. Para ambos os tipos de manejo, a parcela do saldo de radiação (Rn) usada como fluxos de calor latente (&#955;E), variou de 0,27 a 0,87, enquanto que aquela para o fluxo de calor sensível (H) esteve entre 0,13 e 0,74. Com queima na colheita a cultura usou até 5% menos e 6% mais da energia disponível para, respectivamente, os processos de evapotranspiração (ET) e para...
Tipo: Anais e Proceedings de eventos Palavras-chave: Saldo de radiação; Fluxo de calor latente; Fluxo de calor sensível; Latent heat flux; Sensible heat flux.; Net radiation.
Ano: 2014 URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/986242
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Use of MODIS Images to Quantify the Radiation and Energy Balances in the Brazilian Pantanal. Repositório Alice
TEIXEIRA, A. H. de C.; PADOVANI, C. R.; ANDRADE, R. G.; LEIVAS, J. F.; VICTORIA, D. de C.; GALDINO, S..
MODIS images during the year 2012 were used for modelling of the radiation and energy balance components with the application of the SAFER algorithm (Simple Algorithm for Evapotranspiration Retrieving) in the Brazilian Pantanal area. Pixels from the main sub-regions of Barão de Melgaço (BR), Paiaguás (PA) and Nhecolândia (NH) were extracted in order to process microclimatic comparisons. In general, the net radiation (Rn) relied much more on the global solar radiation (RG) levels than on water conditions and ecosystem types, in accordance with the low Rn standard deviation values. The fraction of the available energy used as latent heat flux (&#955;E) were, on average, 65, 50 and 49% for the BR, PA and NH sub-regions, respectively. Horizontal heat...
Tipo: Artigo de periódico Palavras-chave: Evaporative fraction; Latent heat flux; Net radiation; Sensible heat flux.; Remote sensing; Wetlands..
Ano: 2015 URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1029921
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Validation of the Deardorff model for estimating energy balance components for a sugarcane crop Scientia Agricola
Rolim,Glauco de Souza; Escobedo,João Francisco; Oliveira,Amauri Pereira.
The quantification of the available energy in the environment is important because it determines photosynthesis, evapotranspiration and, therefore, the final yield of crops. Instruments for measuring the energy balance are costly and indirect estimation alternatives are desirable. This study assessed the Deardorff's model performance during a cycle of a sugarcane crop in Piracicaba, State of São Paulo, Brazil, in comparison to the aerodynamic method. This mechanistic model simulates the energy fluxes (sensible, latent heat and net radiation) at three levels (atmosphere, canopy and soil) using only air temperature, relative humidity and wind speed measured at a reference level above the canopy, crop leaf area index, and some pre-calibrated parameters...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Energy budget; Net radiation; Latent heat flux; Sensible heat flux; Microclimate.
Ano: 2008 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162008000400001
Registros recuperados: 17
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