Agricultural Water Distribution under Drought Conditions Based on Economic Priorities: Case Study of Qazvin Irrigation District

Abstract

AbstractThis study introduces a practical approach for agricultural water distribution within conveyance and delivery systems based on economic perspectives. To this end, a hydro‐economic approach is used by coupling an economic model, positive mathematical programming (PMP), and a water evaluation and planning system (WEAP) hydrological model. The economic value of water (EVW) is calculated separately for the secondary canals (L1 to L10) by the PMP model, based on simulation of the existing agricultural conditions. The results obtained indicate that under the operational method introduced, the EVW per unit of water (cubic metres) will rise on average by over 28% in comparison to the existing water distribution conditions in the district. Moreover, the results show that the highest and lowest EVW growth took place within farming areas irrigated by the laterals of L10 and L1, respectively. According to the results, the most significant reduction in the cultivation area in the existing cropping pattern was observed in alfalfa and maize compared to other crops under the drought conditions scenario. The results of the study show that the economic benefit (water volume × economic value) will amount to 138 billion IRR (Iranian monetary unit) compared to the primary conditions. © 2019 John Wiley & Sons, Ltd.