Multi-Scale Spatiotemporal Characteristics Assessment of Water and Land Resources Ecological Security in China’s Main Grain-Producing Areas

Water and land resources, as the material foundation of food production, are essential for national food security. Current research has not yet explored the spatiotemporal features of water and land resources ecological security (WLRES) at the urban scale. To fill this gap, this study evaluated WLRES across 180 cities in China’s main grain-producing areas (MGPAs) from 2005 to 2020. A WLRES evaluation system was developed based on the DPSIR framework and the CRITIC method. The Moran’s I and kernel density estimation were utilized to analyze the spatial distribution, variation trends, and spatial autocorrelation of WLRES from different scales. The results demonstrate the following: (1) WLRES in the MGPAs exhibited a fluctuating upward trend, transitioning from “relatively low ecological security” to “moderate ecological security.” (2) The spatial distribution of WLRES was characterized by higher values in the northeast and southwest regions and lower values in the central region, with spatial heterogeneity gradually intensifying. (3) From 2005 to 2016, WLRES exhibited significant positive spatial autocorrelation: cities with high ecological-security levels were concentrated in the northern region, whereas those with low ecological-security levels were clustered in the central and southern of Huang-Huai-Hai Basin. Over time, this positive spatial autocorrelation weakened and eventually vanished. Our research can provide feasible policy references for improving the sustainable development of WLRES in the MGPAs.