*3.1. Cropping Intensity Map*

The developed TMA method was used to estimate cropping intensity in the research area in 2018 (Figure 8). Relatively high cropping intensity could be found in the North China Plain and the center and north of Hubei Province. Furthermore, natural vegetation, water bodies, and built-up areas featured very low intensity values.

**Figure 8.** Cropping intensity of the study area in 2018.

A comparison of the estimated cropping intensity with MODIS false-color composite images and cropping frequency is presented in Figure 9. Since double-cropping areas had high EVI values on DOY 065 and DOY 209 and low EVI values on DOY 145 (Figure 4), they have a magenta tone in the false-color composite images. It can be observed that the high cropping intensity pixels in the estimated cropping intensity correlate well with those magenta pixels in the MODIS image. Additionally, the estimated cropping intensity avoids dividing the cropping intensity into fixed categories like cropping frequency, and thus contains detailed information.
