Measuring aspect

Aspect is the direction that a slope faces. It identifies the steepest downslope direction at a location on a surface. It can be thought of as slope direction or the compass direction a hill faces. Aspect is calculated for each triangle in TINs and for each cell in rasters.

How is aspect measured?

Aspect is measured counterclockwise in degrees from 0 (due north) to 360 (again due north, coming full circle). The value of each cell in an aspect grid indicates the direction in which the cell's slope faces. Flat slopes have no direction and are given a value of -1.

Measurement of aspect

The following shows an input elevation grid and the output aspect grid.

An input elevation grid and the output aspect grid

Why use the aspect function?

There are many different reasons you might want to use the aspect function:

Related Topics