This term means the laws that determine the physical features of plains, mountains and rivers. The term is from The Book of Changes, and it means that the uneven topography of the land, and the direction of rivers and mountains are all determined by certain constant laws. The ancient Chinese believed that both human relationships and all things in the universe are governed by the same laws, and so by observing and following these laws, people can establish social order. In later ages, the term came to cover production, transportation, human settlement and the economic activities affected by the natural environment.

The Book of Changes describes the laws of heaven and earth. By looking at the stars above and the earth below, one can see what is implied and what is obvious. (The Book of Changes)

The movement of the sun, the moon, and stars is tianwen, or the laws governing the movement of the constellations and the change of weather; the distribution and layout of mountains and rivers is dili, or the laws that determine the physical features of plains, mountains and rivers. (The History of the Han Dynasty)