Estimating water requirements of an irrigated mediterranean vineyard using a satellite-based approach

Quantification of evapotranspiration (ET) is a key factor to design management strategies for improving water use efficiency of irrigated viticulture. In the study, an integrated approach of crop coefficients derived from satellite-based normalized vegetation index (NDVI), and a daily soil water balance approach was proposed to accurately estimate evapotranspiration fluxes and crop coefficient values of grapevine plants. The modeled values of Kc and ET were compared with field estimates of crop ET using an energy-balance surface renewal flux tower and adjusted for calibration using the eddy covariance method. The correlation of the measured and modeled Kc exhibits a linear tendency with high coefficient of determination. The study of the soil water balance suggests the importance of soil water storage in grapes. Results of the study validate the use of remote sensing as a tool for accurate estimation of evapotranspiration rates of irrigated grapevine stands.