Annual food production in Ancient Egypt was completely dependent on annual flood level of the Nile river.
Step-by-step explanation:
Water is one of the most important sources for the growth of the crops and for agricultural activities including other important sources such as the nutrition level of the soil, the temperature of the area, the availability of sun light and so on.
Since Egypt is a lot dependent n the Nile river for it's activities of life, the flood level of the same river decided the growth and the production of the agriculture of the country.