A new methodology is suggested for forecasting crop evapotranspiration under standard conditions (also referred to as potential evapotranspiration ETp) by combining VIS-NIR satellite images and numerical weather forecasts. The methodology is proposed for farms where a reliable weather station is operating for assessing current reference evapotranspiration according to FAO Penman-Monteith equation (ET0-PM). Measured weather data are exploited for correcting systematic errors in weather forecasts and for locally calibrating Hargreaves-Samani (HS) equation for estimating the reference ET (ET0-HS). VIS-NIR crop images and current weather conditions are employed for updating a crop coefficient (Kc), analytically derived as the ratio of crop potential evapotranspiration computed with the Penman-Monteith equation (ETP-PM) and ET0-PM. Crop parameters in ETP-PM are assessed by means of albedo and LAI, both retrieved from VIS-NIR images. mathrm {E}mathrm {T} {mathrm {P}} forecasts are then computed with the HS formula by the product ETP-HS = Kc.ET0-HS. The methodology was applied to two experimental farms in Southern Italy, by employing COSMO-LEPS numerical weather forecasts, LANDSAT 8 and DEIMOS-1 VIS-NIR images. ETP-HS forecasts resulted to be more accurate and precise than ETP-PM forecasts. Differently from ETP-PM forecasts, ETP-HS relies only on temperature forecasts, which are generally less uncertain than the forecasts of the other atmospheric variables, which are required for computing ETP-PM.
Forecasting crop evapotranspiration under standard conditions in precision farming / Pelosi, A.; Chirico, G. B.; Bolognesi, S. F.; De Michele, C.; D'Urso, G.. - (2019), pp. 174-179. (Intervento presentato al convegno 2019 IEEE International Workshop on Metrology for Agriculture and Forestry, MetroAgriFor 2019 tenutosi a University of Naples - Department of Agricultural Sciences, ita nel 2019) [10.1109/MetroAgriFor.2019.8909263].
Forecasting crop evapotranspiration under standard conditions in precision farming
Pelosi A.;Chirico G. B.;D'Urso G.
2019
Abstract
A new methodology is suggested for forecasting crop evapotranspiration under standard conditions (also referred to as potential evapotranspiration ETp) by combining VIS-NIR satellite images and numerical weather forecasts. The methodology is proposed for farms where a reliable weather station is operating for assessing current reference evapotranspiration according to FAO Penman-Monteith equation (ET0-PM). Measured weather data are exploited for correcting systematic errors in weather forecasts and for locally calibrating Hargreaves-Samani (HS) equation for estimating the reference ET (ET0-HS). VIS-NIR crop images and current weather conditions are employed for updating a crop coefficient (Kc), analytically derived as the ratio of crop potential evapotranspiration computed with the Penman-Monteith equation (ETP-PM) and ET0-PM. Crop parameters in ETP-PM are assessed by means of albedo and LAI, both retrieved from VIS-NIR images. mathrm {E}mathrm {T} {mathrm {P}} forecasts are then computed with the HS formula by the product ETP-HS = Kc.ET0-HS. The methodology was applied to two experimental farms in Southern Italy, by employing COSMO-LEPS numerical weather forecasts, LANDSAT 8 and DEIMOS-1 VIS-NIR images. ETP-HS forecasts resulted to be more accurate and precise than ETP-PM forecasts. Differently from ETP-PM forecasts, ETP-HS relies only on temperature forecasts, which are generally less uncertain than the forecasts of the other atmospheric variables, which are required for computing ETP-PM.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
