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Parameterization of a two-layer model for estimating vineyard evapotranspiration using meteorological measurements

Author:
Ortega-Farias, S., Poblete-Echeverría, C., Brisson, N.
Source:
Agricultural and forest meteorology 2010 v.150 no.2 pp. 276-286
ISSN:
0168-1923
Subject:
Vitis vinifera, grapes, fruit crops, vineyards, evapotranspiration, estimation, meteorological parameters, microirrigation, solar radiation, heat transfer, soil temperature, model validation, soil water content, Chile
Abstract:
The Shuttleworth and Wallace (SW) model with variable canopy resistance was evaluated to estimate evapotranspiration (ETv) from a drip-irrigated Merlot (Vitis vinifera L.) vineyard trained on a vertical shoot-positioned (VSP) system. This vineyard is located in the Talca Valley, Region del Maule, Chile (35°25′ LS; 71°32′ LW; 125m a.s.l). The performance of the SW model was evaluated using the eddy-covariance method on a 30min time interval. Also, sub-models to estimate net radiation (Rn) and soil heat flux (G) were used in the SW model. A good agreement between observed and estimated values of Rn was found with a root mean square error (RMSE) of 33Wm⁻² and a mean absolute error (MAE) of 24Wm⁻². Also, the SW model was able to estimate latent heat flux with RMSE and MAE of 34 and 21Wm⁻², respectively. On a daily basis, results indicate that the SW model was able to predict the ETv with RMSE and MAE values of 0.51 and 0.41mmd⁻¹, respectively. These results suggest that it is possible to directly estimate ETv over unstressed grapevines using meteorological data and soil moisture measurements.
Agid:
775708