Fig. 1. Desertification area (a) and variability (b) in China from late 1950s to 2010 (according to Wang Tao et al. ^[113])

Fig. 2. A schematic diagram of the response of sandstorms to human activities and Asian monsoon changes in the eastern monsoon marginal region of China (according to Chen^[130])

Fig. 3. Comparison of saline-alkali land and sandy land in the Huang-Huai-Hai Plain before and after treatment

Fig. 4. Distribution of selenium belt^[236]

Fig. 5. Principle of geodetector (according to Wang Jinfeng et al. ^[273]) (The study area consists of two layers: the explained variable Y and the spatial stratification X; X can be used to express geographical classification or partitioning. $\bar{Y}$ and $σ^{2}$ are the mean value and variance of the entire study area, $\bar{Y}_{h}$ and $σ^{2}_{h}$ are the mean value and variance of the h layer)