A multistage irrigation water allocation model for agricultural land-use planning under uncertainty

In practical agricultural water management problems, fluctuating water availabilities and demands, varying crop yields and economic profits, as well as changing irrigation patterns in both temporal and spatial scales are challenged decision makers. These challenges are being further compounded by rapid socioeconomic development associated with increased food requirement and decreased resources accessibility. A multistage irrigation water allocation (MIWA) model is developed for agricultural water management and cropland use planning in response to such complexities. The MIWA model is derived from incorporating interval parameters within a multistage stochastic programming (MSP) framework, such that uncertainties expressed as interval parameters and probability distributions can be tackled, and the real-time dynamic irrigation water management can be conducted. It can also support the analysis of various policy scenarios that are associated with different levels of economic consequences when the pre-regulated crop targets are violated over a multistage context. The MIWA model is then applied to a real case of planning agricultural water management and cropland use pattern in Zhangweinan River Basin, which is one of the driest regions in China and faces serious water scarcity. Solutions of irrigation targets for multiple crops as well as actual water-allocation patterns in different growth stages can help determine optimized water and land use in agricultural system, which could hedge appropriately against future available water levels in more profitable and sustainable ways.