What does the "percent of slope" refer to in landscaping?

The term "percent of slope" refers to the vertical rise in relation to the horizontal run, expressed as a percentage. Specifically, it is a measure that indicates how steep a slope is. This calculation is crucial in landscaping, particularly when designing drainage systems, pathways, or any feature that involves elevation changes.

For example, if there is a rise of 3 feet over a run of 100 feet, the slope would be calculated as (rise/run) x 100, resulting in a 3% slope. Understanding the percent of slope helps landscapers create functional and aesthetically pleasing designs that also mitigate issues like erosion or water pooling. Hence, the relationship of rise to run is fundamental in assessing how steep a slope is, making this option the most accurate answer regarding the concept of "percent of slope."

The other options address different aspects of landscaping that do not pertain directly to the measurement of slope. The total area of the site is related to land use and planning, the length of paving materials used pertains to material estimation, and the depth of planting beds concerns horticultural considerations, but none of these define the percent of slope.