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Modelação das trocas energéticas em videira com base em termometria de infra-vermelhos
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Orientador(es)
Resumo(s)
Com o objectivo de validar um modelo de estimação da transpiração da videira a
partir da medição da temperatura radiativa da superfície da sebe, instalou-se um
ensaio numa vinha da casta Touriga Nacional, na região do Dão. Além de permitir
caracterizar a evolução diurna dos componentes do balanço energético, conclui-se
que o modelo permite uma boa estimação dos valores diários da transpiração---------------------------------------------ABSTRACT--In order to validate a model to estimate vine evapotranspiration based on its
surface temperature, measured with infrared thermometers, a field trial was
established in a vineyard in the Dão region. Vines were fully irrigated with a drip
irrigation system. Soil water content was measured with capacitive sensors down
to a 2 m depth. Surface temperature was measured with infrared thermometers
(Tr), positioned above the plants so as to assure that only fully exposed leaves
were viewed by the instrument. Climatic variables were measured at the same
time in a nearby meteorological station.
The model developed separates net radiation measured over the surface (Rn)
between the components of the canopy, vines (Rnc) and soil+soil cover (Rns). To
calculate sensible heat flux from the vines (Hc) using Tr, instead of the
aerodynamic temperature, an additional resistance between the leaves and the
mean source of the flux is introduced. Latent heat flux from the plants (lEc) is
then calculated as the residual term of the energy balance.
Results show that the model properly estimates transpiration from the vines, and
thus that it is possible to study energy fluxes in partial cover/row crops with a
simplified, low maintenance and reliable set of equipment
Descrição
Palavras-chave
videira termometria de infra-vermelhos troca energética grapevine energy exchange infrared thermometry
Contexto Educativo
Citação
Pereira, L.S.; Varennes, A.; Oliveira, C.; Dias, S.F. - Engenharia dos biossistemas. Cem anos de investigação no centenário do ISA. Lisboa: Colibri/CEER, 2011, 466 p.