Water Allocation Optimization Model for Agricultural Irrigation: A Case Study of Hali Dam, Saudi Arabia

Abstract:

Agricultural scarcity is a worldwide issue that required the need for optimal water allocation of irrigation water systems, especially in semi-arid and arid regions. In Saudi Arabia, the agriculture demand forms more than 70 percent of total demand which required to find practical and applicable water conservation plans that help to mitigate the impact of water shortage and potential droughts. In this paper, we present an optimization model for agricultural irrigation systems. The model is developed at helping to optimally allocate water to cultivate crops in order to maximize the net benefit for each region by using monthly reservoir operation. The model maximizes the net crop income and determines the mix of type and size of the cultivated crop to each region considering monthly water availability in the reservoir. Constraints in the optimization model include: (1) monthly water availability in the reservoir (2) monthly irrigated farmlands for crops (3) monthly water demand for crops, and (4) monthly proportional sharing rules (PSR) for each region. The model is solved through a linear programming (LP) algorithm in the general algebraic modeling system (GAMS). The optimization model performance is applied to a hypothetical example for the validity and accuracy. However, the model will be assessed through Hali Dam, Saudi Arabia which is supply water to Makkah and Aseer Regions. The expected results are to know the most economical and size crops by taking the proportional sharing rules (PSR) for each region into account.