The Aspect (Spatial Analyst or 3D Analyst) tool calculates the direction in which slopes are facing. Values are given in degrees in regards to the degrees on a compass (with north as 0 and 360 degrees).
To calculate the aspect of the terrain (Fig. 43):
- Type “aspect” into the Search window (or browse to Spatial Analyst Tools > Surface > Aspect in the ArcToolbox).
- Select the Aspect (Spatial Analyst or 3D Analyst) tool.
- Choose the DEM as the input raster.
- Save the output raster as aspect.
- Click OK.
In the TOC the results (Fig. 44) can be seen in degrees.
43. The Aspect tool
Fig. 44. The result of the Aspect calculation from the DEM.