Abstract
Agricultural water resources face growing pressure from rising food demand and environmental changes. In large agricultural irrigation areas, water and land use is closely linked to energy consumption, carbon emissions, and food production. Therefore, regulating the water–land–energy–food–carbon nexus under multiple external changes is essential for achieving sustainable agriculture. This study aims to optimize water and land allocation in large agricultural irrigation areas to enhance yields and reduce carbon emissions under different external environments and production conditions. A spatial–temporal synergistic optimization and regulation model for water and land resources in large agricultural irrigation zones is developed. Based on 191 representative irrigation districts in Heilongjiang Province, multiple scenarios are constructed, including water-saving irrigation, climate change and low-carbon irrigation energy transitions. Optimal solutions are identified using the Non-dominated Sorting Genetic Algorithm Ⅲ. The results indicate that, after optimization in the current scenario, crop production increased by 2.13%, carbon emissions decreased by 1.23%, and irrigation energy productivity rose by 9.33%. Concurrently, water-saving irrigation should be prioritized in western regions. This study provides an efficient water management pathway for major food production regions.