Seguimiento de los flujos de calor sensible y calor latente en vid mediante la aplicación del balance de energía METRIC

Abstract

Resumen: En este trabajo se presenta el seguimiento de los flujos de energía en un cultivo de vid bajo riego, obtenidos a partir del modelo de balance de energía METRIC (Allen et al., 2007b). Este modelo resulta operativo al utilizar un método de calibración interna definido a partir de la selección de píxeles con valores extremos dentro de la escena. De esta manera se obtuvieron mapas de radiación neta (Rn), flujo de calor en suelo (G), calor sensible (H), calor latente (LE), evapotranspiración (ET) y coeficiente de cultivo (Kc). Estos valores fueron validados con registros obtenidos en el sitio, utilizando una torre de flujos turbulentos (covarianza de torbellinos). El RMSE fue 43 W m

Evapotranspiration of sorghum from the energy balance by METRIC and STSEB

“…The comparison with the in-situ measurements of daily ET shows RMSE values of 0.8 mm d -1 with METRIC and 0.7 mm d -1 with STSEB. These results are similar to those obtained by other authors, such as the error of 0.6 mm d -1 in a vineyard using the METRIC model (González-Piqueras et al, 2015) or the error of 0.5 mm d -1 obtained by the two-source model (González-Dugo et al, 2012). Results in this study demonstrate the capacity to obtain the ET also in sorghum by satellite.…”

“…For G, the RMSE values of 5 W m -2 with METRIC and 21 W m -2 with STSEB were obtained. The observed tendency to overestimate G values has also been found in other studies (González-Dugo et al, 2012;González-Piqueras et al, 2015). According to Bastiaanssen (2000), the term G is the one with greatest problem of precision in energy balance models.…”

“…Energy balance models can be classified into two types: one-source models (Oliveira et al, 2014;Paço et al, 2014;González-Piqueras et al, 2015;Madugundu et al, 2017) or two-source models (Sánchez et al, 2011;González-Dugo et al, 2012;Sánchez et al, 2014). These models are based on the surface energy balance through the determination of the latent heat flux (LE), estimating net radiation (Rn), sensible heat flux (H) and soil heat flux (G) (González-Piqueras et al, 2015).…”

Evaluation of Penman-Monteith Model Based on Sentinel-2 Data for the Estimation of Actual Evapotranspiration in Vineyards

“…The results obtained at instantaneous time scale both METRIC and TSEB-PT are within the range of error reported in vineyards, with a RMSE ranging from 40 to 95 Wm −2 [21,90,91] in METRIC and from 47 to 89 Wm −2 in TSEB-PT model [28,30,92]. Additionally, both METRIC and TSEB-PT showed similar performance in terms of RMSE, %RMSE and d 1 .…”

“…Analyzing different timescales where instantaneous λE was extrapolated to daily ET, 7-day and monthly ET (Table 5), the best agreement index (d 1 ) corresponds to the RS-PMS model (0.7), followed by RS-PML (0.58), TSEB-PT (0.56) and METRIC (0.5), which is consistent with respective RMSE and %RMSE values. Therefore, daily ET values modeled by METRIC have a slightly higher RMSE than those reported in vineyards [22,91,98], ranging from 0.4 to 0.8 mm day −1 . These differences possibly are due to the extrapolation method chosen, since in addition to the approach used in this research (λE/Rs ratio), there are other common methods such as ET/ET 0 [22,91] and ET/R N -G ratio [98].…”