Slope angle

Slope angle is measured from the horizontal in degrees, and the dominant slope within the map unit area is recorded as one of the following seven slope groups (Table 6 - section 2.3 of LUC Handbook).

In the field the dominant slopes can be measured by hand-held Abney level or clinometer, or estimated by eye. Slope can also be calculated from a Digital Elevation Model (DEM) where one of suitable accuracy and precision is available.

Slope groupings are: 

A map polygon with a single slope classification is recorded as a single letter code (e.g. A for flat to gently undulating land), but compound slope classifications can be used where more than one major slope group occurs in a map unit. For example, D+E slopes means that slopes are mainly strongly rolling but the map unit contains a significant area of land with moderately steep slopes.  Slopes which are borderline between two slope groupings can be recorded in the form D/E (i.e. most slopes are 20–21 degrees).  The superscript ' is used to denote dissected slopes, and + or - to denote where slopes are nearer the upper or lower end of the slope group.