Fig. 3: Spatial pattern of three types of land-use transition under the ripple effects over 20 years.

First, we identified the three types of land-use transition based on the 30 m resolution land-use dataset. They are built-up land encroaching farmland (Frl. to Btl.), farmland reclaimed from natural land (Nat. to Frl.), and natural land supplied by unused land (Unu. to Nat.). Then, the area proportion of the three types of transition in each 10 × 10 km pixel cell was calculated and set as the components of tricolors to show the spatial pattern of land-use transition. The figure highlights farmland loss in the eastern coastal developed areas and reclaimed in the northern part of China.