Integrated agriculture water management optimization model for water saving potential analysis

This paper studied on the quantification of agriculture water savings under water integrated optimal management and analyze the economic increment of agriculture water savings. First, an integrated agriculture water management optimization model composed of a planting structure optimization model and water resources allocation under conjunctive use of surface water and groundwater optimizing model is built in this paper and applied to Fendong District of Fenhe Region in Shanxi Province, China. Resilience of water utilization and saving inside agriculture have been fully developed through detailed expressions of demand process of multi crops and the interaction and transformation between surface water and groundwater. Optimal solutions of planting structure and corresponding water resources allocation scheme indicate that water demand and supply are more reasonable after assembling crop water demand to flood seasons. Water saving could be realized in the premise of maximum economic benefit after integrated optimization management. Next, active water saving and passive water saving scenario have been set to analyze the correlativity between water saving quantity and maximum economic benefit through adopting integrated agriculture water management optimization model. The results show that water saving potential and agriculture benefit demonstrate a negative correlation. The interval linear function of water saving-effect comprised of two scenarios is used to represent this negative correlation. Consequently, approximately 10% of surface water could be saved in Fenhe Region under current planting scale. Finally, an optimization model for agricultural water transfer are formulated to the further study on agriculture water savings reallocation by maximizing incremental benefit of water resources. The interval linear function of agriculture water saving-effect and water production function of the second industry and tertiary industry have been introduced to obtain agriculture water transfer trend under various circumstances. For Fenhe Region, agriculture water transferring to the second industry (533 × 104 m3) and tertiary industry (235 × 104 m3) could bring an incremental benefit about 8.66-8.94 billion RMB, and 90.2-93.1 RMB for 1 m3 of irrigation water, which exhibits a huge potential of economic benefit of agriculture water savings. The results indicate that optimization model for agricultural water transfer is an efficient way to analyze economic value of irrigation water and provide agriculture water transfer strategies.