Current status, causes, and future conservation strategies for soil productivity degradation across various geographic regions. (a) The degradation risk within different regions of China was generated using kriging interpolation based on the results from Section 3.3. The relative levels of PI, V, and SE (normalized), the primary cause of degradation, and future conservation measures in Northwest China (b), the Sichuan Basin and surrounding regions (c), the Yunnan-Guizhou Plateau (d), the Northeast China Plain (e), the Loess Plateau (f), and Eastern China (g). Data for Taiwan are not available in this study.