Human Settlement, Inhabitation, and Travel Environment Studies in Plain Region

The land with relatively small elevation is called the plain, the altitude of which is mostly 0–500 m, and generally in coastal areas. Low plain is 0–200 m above sea level, and high plain is 200–500 m above sea level. The main feature is that the terrain is low and flat, undulating gently, the relative altitude is no more than 50 m generally, and the slope is below 5°. It is different from the plateau due to its low height and different from hills due to its small undulation. The plain occupies 12% of the total dry land area of China.