Modeling supplemental Irrigation Water Demand

A deterministic hydrology model (ARM-II) was modified to simulate the application to supplemental irrigation water. The model is especially useful to create times series of irrigation applications for planning purpose in climates where natural rainfall provides the major source of water plant growth. Fifty years of synthetically generated precipitation and pan evaporation data were used as model inputs to simulate a long record of irrigation water demand. Annual water application depths for a corn crop grown on a sandy loan soil in the piedmont agricultural region of Georgia conformed to a Log-Pearson Type III probability distribution. Such information is useful in cost-benefit analyses and water allocation planning.