Modelling evapotranspiration in a spring 1 wheat from thermal radiometry: Crop coefficients and E/T partitioning

Wheat is one of the crops occupying the largest areas in the world (218 million ha in 2013). Understanding the land-atmosphere energy exchanges over these croplands becomes important not only for agronomy but also for climatic and meteorological aspects. This study continues previous work on the est...

Descripción completa

Detalles Bibliográficos
Autores: Sánchez Tomás, Juan Manuel, López-Urrea, Ramón, Doña Monzó, Carolina, González-Piqueras, José, Niclòs Corts, Raquel
Tipo de recurso: artículo
Fecha de publicación:2015
País:España
Institución:Universidad de Castilla-La Mancha
Repositorio:RUIdeRA. Repositorio Institucional de la UCLM
OAI Identifier:oai:ruidera.uclm.es:10578/7956
Acceso en línea:http://hdl.handle.net/10578/7956
Access Level:acceso abierto
Palabra clave:Radiometric Temperature
Evapotranspiration
Crop Coefficient
Two-Source Enery Balance
Spring Wheat
Descripción
Sumario:Wheat is one of the crops occupying the largest areas in the world (218 million ha in 2013). Understanding the land-atmosphere energy exchanges over these croplands becomes important not only for agronomy but also for climatic and meteorological aspects. This study continues previous work on the estimation of actual evapotranspiration and the assessment of crop coefficients of sorghum, sunflower, or canola. Two variations of a simple two-source energy balance (STSEB) approach were used in combination with land surface temperature measurements to calculate hourly and daily values of surface fluxes and actual evapotranspiration (ET). An experiment was carried out during the spring season of 2014 in Las Tiesas experimental farm in Barrax, Spain. Soil and canopy temperature components together with meteorological variables and biophysical parameters were measured from planting to senescence. Comparison to lysimeter measurements showed calculation errors of ±0.11 mm h-1 and ±0.8 mm d-1 for hourly and daily ET values, respectively, whereas an underestimation no greater than 4% resulted from the entire campaign. Partition between soil and canopy components yielded a ratio of evaporation (E) to transpiration (T) of 36% to 64%, respectively, for the total growing season. Dual crop coefficients were also calculated and compared to those proposed by FAO56. Although separate E and T measurements were not available, similar results between the STSEB and FAO 56 models demonstrate the utility of the STSEB for investigating management strategies aimed at increasing crop water use efficiency.