Planning Model of Irrigation District

Abstract
A linear optimization model for planning the management of Irrigation District No. 38, in the State of Sonora, Mexico, is presented. The model considers the yield, price, and production cost of twelve primary crops; the land restriction on cropped areas; the storage capacity of the existing reservoir and aquifer; the reservoir net inflows; the evaporation, releases, and spillages from the reservoir; the surface water and groundwater requirements of the crops; the quality of the mix of surface water and groundwater; and the requirements of other resources, such as fertilizer, pesticide, seed, equipment, and labor. The model gives the cropping pattern and the monthly schedule of reservoir releases and aquifer withdrawals that maximize the annual profit in the district. Solutions to the model facilitate an evaluation of the effects of net annual inflows on profits and cropped areas, and provide an indication of the levels of inflow that can be used for planning the operation of the irrigation district.