Optimizing the structure of food production in China to improve the sustainability of water resources

The conflict between the growing demand for food and limited water resources is intensifying. To further elucidate the relationship between food and water, we construct a water footprint life cycle assessment framework for food products and propose a modified algorithm for measuring a food's water footprint to assess the virtual water transfer between grain crops and animal products. To address the mismatch between regional water resources and food production, we propose a novel optimization model for food production structure, with both reducing water use and maintaining food security as its objectives. Using 2020 as an example, the analysis proposes an adjusted food production structure for China at national, regional, and provincial scales. The results show that 24.9 % of water consumed by grain crops is transferred to animal products through feed grain. The total water footprint of food production in China is 820.8 billion m3, with the blue water footprint accounting for 32.9 % of that total. The blue water footprint for food production in northern China is 161.8 billion m3, which is much larger than 108.2 billion m3 in southern China. Water scarcity is also greater in northern regions, which produce the majority of grain and animal products. Our optimization shows that a reasonable food production structure can balance water resources and food security by remarkably reducing China's total blue water footprint and increasing food production in the south while reducing production in certain northern provinces to ensure sustainable regional development.