Measuring Slope Steepness

The easiest way to determine the percent slope of an area is to measure the change in height (elevation over a measured distance), then calculate the percentage of slope. Use the following formula to determine slope:

Rise ÷ Run = Slope %

OR

(Change in elevation ÷ measured distance = slope %)

e.g. 30 metres  ¸ 100 metres = .3 or 30% 

Stages:

• Calculate map area in km²

• Place 10 X 10 grid overlay over map

• Calculate % slope for each grid square

• Present results as an area average or median slope for the area (see chart example below)

Slope Angle Index Chart

Transparent grid overlay (11 X 11)

Standard slope descriptors