Figure 2-14. Percent of Slope Overlay.
When this overlay is added to Figure 2-13, the analyst may be able to eliminate
otherwise likely avenues of approach based on trafficability.
An easier method of determining the percent of slope is to construct a slope
calculator. To do this you must count the number of contour intervals for a
distance and draw them by using tick marks on a piece of translucent paper.
matching the contour lines with those used to determine the first percentage
slope, you can determine very quickly if the percentages are the same. This
time in computing each difference in elevation.