Efficient irrigation water allocation and its impact on agricultural sustainability and water scarcity under uncertainty

Agriculture is a key economic sector in developing countries that are facing challenges of low efficiency of water resources utilization and of shrinking water supply. This study develops an optimization model for the allocation of agricultural irrigation water to improve irrigation water use efficiency (IWUE), considering uncertainties of fluctuating water supply. Then, it assesses the impact of efficient water allocation on the sustainability and water scarcity under different levels of water supply. This study can help answer questions as to how to optimal allocate limited water supplies to different crops and different subareas under uncertainty to improve IWUE, how water shortage affects economic, social, and environmental aspects, and what the relationship between system sustainability and water shortage is. To demonstrate its feasibility, the proposed models are applied to an irrigation district in northeastern China. These models can also be applied to other regions that suffer from water scarcity. Results of application are found to be satisfactory for explaining the impact of agricultural irrigation water allocation on net economic benefit, water resources allocation equity, total greenhouse gas emissions, and water scarcity footprint under different water supply conditions. This study provides insights into tradeoffs amongst resources, economy, society, and environment in irrigated agricultural systems under uncertainty.