Using HYDRUS-1D for estimating evapotranspiration and soil water content of irrigated winter wheat under different water management in a semi-arid region of Morocco

The objective of this study is to evaluate the potential of the HYDRUS-1D model to estimate actual crop evapotranspiration (ETa) and soil moisture (θ) in the root zone (0-50 cm) over irrigated winter wheat under different water management in a semi-arid region of Tensift-basin (in central Morocco). The study fields were flood irrigated and equipped with meteorological stations, soil moisture sensors, and eddy covariance systems. The HYDRUS-1D simulations of ET and θ were performed daily during the 2002/2003 growing season. Firstly, the main parameters of Van Genuchten (1980) hydraulic functions used in HYDRUS-1D model were determined based on the comparison between measured and simulated soil moisture in the root zone. Afterward, the ETa and θ simulations results, considered as the output of the HYDRUS-1D model, were compared against the measurements. The obtained outcome shows that the HYDRUS-1D model simulates ETa and θ reasonably well. The average values of the root mean square error (RMSE) between the observed and measured ETa and θ were 0.58 mm day^-1 and 0.04 cm³ cm^-3, respectively.