Irrigation water management is one of important key aspects in operating irrigated agriculture. Under changing climate, proper use of water is critically important. The increase in global temperature will definitely change the demand of crop for water. Thus, proper planning of irrigation projects will require best estimates of crop water demand of crops. The results from this book detail the crop water requirement of tomato under different scenario of changing climate. The results are based on Models (Aqua-crop) and also the field experiments that have been conducted for the last four years.