Optimal Allocation of Irrigation Water by Balancing Water Use and Food Production

A deterministric optimization model is presented to allocate irrigation waters to blocks of crop fields in an agricultural district. In order to prevent excessive agricultural water use and enhance water productivity, two competing objectives, i.e., minimization of water withdrawal from a river and maximization of crop yield, are formulated. Water balances in a river, a field block and a channel network connecting some field blocks are considered as constraints. Adjusting a weight in a synthesized objective function results in producing a set of noninferior solutions, which can be used to analyze a trade-off between the two objectives. The optimization model is applied to a hypothetical irrigation district for rice production, successfully generating optimal allotments of irrigation waters to blocks of paddy fields and optimal water withdrawals.