Water-land-food nexus for sustainable agricultural development in main grain-producing areas of North China Plain

Abstract

Stable and sustainable food production is an important guarantee for national security, economic development, and social stability. Water and land resources are key elements of grain production. Moreover, their unbalanced distribution will threaten sustainable agricultural development and regional food security. The main grain-producing areas in North China are important grain production bases in China, and it is vital to investigate the water-land-food nexus in order to promote sustainable regional grain production and sustainable use of land and water resources. Therefore, this study adopts the Gini coefficient and the water-land matching coefficient for exploring the water-land nexus in the main grain-producing areas of North China from 2000 to 2020. The water-land-food nexus considering grain crop production structure is further explored from spatial and temporal multi-scales. The results show that: (1) the Gini coefficient presents an increasing trend in the main grain-producing areas in North China from 2000 to 2020, indicating an increasing imbalance of the matching degree of agricultural water and land resources among inter-regions, with the most balance in Jiangsu Province, whereas the most imbalance in Anhui Province. (2) There are significant differences in WL nexus and WLF nexus among regions, showing a spatial pattern of "worse in the north and better in the south". Regarding on the WLF nexus, 60.8% of the municipalities are mismatched or mildly mismatched. (3) The cities such as Hengshui, Cangzhou and Suzhou belonged to the low WL-low WLF and high WL-low WLF should be considered as key targets when formulating policies. Adjusting the wheat-maize biannual system, optimizing the grain cultivation structure adapting to water resources distribution, promoting semi-dryland farming, reducing the intensity of irrigation water use and developing low water-consuming and high-yielding crop varieties are important for these regions. (4) In addition, improving field water-saving irrigation facilities, utilizing transit surface water resources reasonably and adhering to water conservation and water use target control are also essential measures for agricultural water management in North China Plain.