This study investigates the impact of climate change and land use change on water resources and food security in Jordan. The country is dominated by arid climate with limited arable land and water resources, where the per capita share of water is less than 145 m 3 /year. The study focused on crop production and water resources under trends of anticipated climate change and population growth in the country. Remote sensing data were used to determine land use/cover changes and rates of urbanization, which took place at the cost of the cultivable land. Recession of irrigated areas led to lesser food production and food security. Outputs from crop production and water requirements models, in addition to regression analysis, were used to estimate the projected increase in agricultural water demand under the scenarios of increased air temperature and reduced rainfall by the

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Most crop, hydrology, and water quality models require the simulation of evaporation from the soil surface. A model developed by J.T. Ritchie in 1972 provides useful algorithms for estimating soil evaporation, but it does not calculate the soil water redistribution resulting from evaporation. A physically‐based model using diffusion theory, described previously by Suleiman and Ritchie in 2003, provides efficient algorithms for soil water redistribution and soil evaporation. However, the model is appropriate only for second stage drying when the soil in the entire profile being simulated is below the drained upper limit (θDUL) and no more drainage occurs due to gravity. This paper extends the Suleiman–Ritchie model for soil water contents higher than θDUL where soil evaporation rates are usually higher than second stage drying. New algorithms were developed for these wetter conditions that are functions of soil depth and the wetness of the near‐surface soil. New model parameters were calibrated with data measured in laboratory soil column studies. The resulting model was integrated into DSSAT‐CSM (Decision Support System for Agrotechnology Transfer Cropping Systems Model). Simulated soil evaporation rates and soil water contents obtained using the Suleiman–Ritchie model with the developed extensions and the previous DSSAT soil evaporation model were compared and evaluated with field measurements of soil water content during several drying cycles for parts of 3 yr in North Central Florida. Computed soil water contents from the model agreed well with the measured soil water contents near the surface, and provided more accurate estimations than the original DSSAT soil evaporation model, especially for the 5‐cm surface layer.