Dynamic simulation of the water-land-food nexus for the sustainable agricultural development in the North China Plain

Inter-regional trade of agricultural products based on the flow of agricultural virtual resources is of great importance for sustainable agricultural development. We focused on grain crops (rice, wheat and maize) in the North China Plain (NCP), and used the Penman-Monteith equation to simulate crop water requirements. We further analyzed the flow of virtual land and virtual water associated with the grain trade using an environ-mentally expanded multi-regional input-output model. The coupling coordination of land, water, and food was evaluated to assess the rationality of regional agricultural production resource allocation. Between 2007 and 2017, agricultural virtual land and virtual water embodied in the grain trade between the NCP and other areas increased by 48.10 % and 34.41 %, respectively, indicating that the NCP is gradually consolidating its position as the main production area and distribution center of crops in China. Agricultural virtual resources in the NCP were mainly transported to the southeast coastal region, with an overall trend of resource movement from north to south. The total supply of agricultural land and water resources markedly increased in the NCP, whereas the transfer of virtual resources across regions showed a decreasing trend. Because of the irrational structure of crop cultivation and unevenness of regional resource allocation, the coupling coordination of the water-land-food nexus in the NCP is much lower than the national average. This study provides important information on the trade flows and coupling relationships of virtual water and land resources of three major food crops, which will help to alleviate resource pressure in agricultural production and promote sustainable agricultural development in the NCP.