The book summarized that, based on needed input data's Crop water requirement and irrigation scheduling of onion in selected districts of Metekel zone were estimated using Aqua Crop and CropWat. Model performance indicators were used to show relationship between simulated results of CropWat and the simulated results of AquaCrop. This study also shown that there was a strong close relation between simulated crop water requirement values of CropWat and the simulated crop water requirement values of AquaCrop. Hence Model performance indicators showed that the models well simulated in all...