Slope ratios

Every single place on-line that I can find that describes a slope ratio defines it as the ratio of drop to horizontal distance (rise-to-run ratio), and then gives an example of the exact opposite--for example, a 2:1 slope ratio is illustrated by a one foot rise for a two-foot run. Is it that there was a mistake in one landscaping textbook 50 years ago that got perpetuated, so that now everyone in the landscaping business is confused?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

In civil engineering, earth slopes are described as 1-1/2:1, 2:1, 3/1, 4:1, etc. This means one foot of rise in the stated number of feet. Perhaps there has been a mistaken use of terminology from one field (earthwork construction, for example) used in another field such as carpentry where other expressions are customary.
SJF
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.