Land type

Features of ground features

Corresponding image

Bare land

Brown or light yellow, uniform tone or yellow with gray, irregular shape

Sand

Gray or dark gray, uniform tone or white in gray, irregular shape

Vegetation

Dark green or black with green strips, gray with white, obvious boundary, and the shape is mostly dot or partial circle

Collapse pit

The whole is black, the edge part is brownish yellow, and the shape is mostly circular, which is generally closed

Crack

Black or light yellow, uniform internal tone, generally linear, streamline, curved strip, linear outline as a whole and obvious boundary