Optimal Allocation of Water Resources Model for Different Growth Stages of Crops under Uncertainty

Abstract

In this study, an integrated interval nonlinear programming model based on Jensen’s water production function is proposed for the optimal allocation of water resources under uncertainty in agricultural irrigation. The model provides an effective approach to solve the problems for crop irrigation schedules and to successfully deal with the inconsistencies in crop water requirements and rain capacity. The model can allocate the limited water to different growth stages of crops based on Jensen’s crop water production function, which further improves water use efficiency. The method provides the means to promote the development of water-saving irrigation and further improves the economic value of water resources. Two major advantages make the model unique in comparison to the other optimization techniques. First, it can solve the uncertainties of the agricultural water resources system, and the results are given in the form of intervals, which can provide more leeway for decision makers. Second, the rainfall was divided into 18 stages with 10 days per stage in this paper (each of the crop growth stages were matched with different stages); then, the limited water resources were optimally allocated to different crops in different growth stages based on Jensen’s model. The model not only increases the output per unit of water but also improves water use efficiency. In this paper, the Yongchang irrigation district in Wuwei was taken as an example to demonstrate the feasibility of the proposed model. The results are helpful for water resources managers in making decisions about water allocation and striking a balance between environmental and economic objectives.