Exploring the rules of cropland elevation uplift in China.

Cropland elevation uplift (CLEU) has recently become a new challenge for agricultural modernization, food security, and sustainable cropland use in China. Uncovering the rules of CLEU is of great theoretical and practical significance for China's sustainable agricultural development and rural revitalization strategy. However, existing studies lack in-depth disclosure of multi-scale CLEU evolution rules, making it difficult to support the formulation of specific cropland protection policies. We analyzed the spatio-temporal evolution and multi-scale CLEU in China from 1980 to 2020 using the Lorenz curve, gravity center model, hotspot analysis, and cropland elevation spectrum. The results indicated that the center of gravity of cropland moved to the northeast from 1980 to 2000 and then shifted to the northwest. The spatial distribution of cropland became increasingly imbalanced from 1980 to 2000. The change hotspots clustered in the northwest and the northeast, whereas cold-spots were mainly in southeastern China. The average elevation of cropland increased by 17.38 m, and the elevation uplift rule in different regions differed evidently across scales. From 1980 to 2000, all provinces except Xinjiang, Inner Mongolia, Gansu, and Yunnan exhibited CLEU, with Qinghai, Tibet, Beijing, and Guangdong showing the most noticeable uplifting. The CLEU can alleviate the shortage of cropland to some extent. However, without a planning constraint, the CLEU will lead to the increase of ecological risk and food security risk. [ABSTRACT FROM AUTHOR]