Optimization allocation of irrigation water resources based on crop water requirement under considering effective precipitation and uncertainty

Today, water resources shortage becomes more and more serious. In reality, uncertainties are inevitable due to the complex of irrigation system. Therefore, an inexact interval programming model was developed for optimizing irrigation water resources, which was also applied to a case study in Jinghuiqu irrigation district, Shaanxi Province, China. In the case study, maximum economic benefit was made as planning objective and crop evapotranspiration and effective precipitation were took under consideration, which have significant influence on optimization allocation of irrigation water resources. Different optimal irrigation and planting structure schemes, which have the ability to conjunctive use of surface water and groundwater, were obtained under different representative hydrological year. From the results, water resources shortage is very serious which have made great negative influence on the development of Jinghuiqu irrigation district. In addition, a lot of water resources has been saved by introducing effective precipitation in the model, such as 47.36% of total water consumption was saved in maize when P = 25%. Furthermore, the decision makers can choose the desired optimal scheme according to the actual situation.