What is the rise over run, the measurement of the change in elevation over a distance?

• A. Slope
• B. Elevation
• C. Stream gradients
• D. Cartesian coordinate system

Answer: (A)

Rise over run is the concept of slope—the ratio that describes how steep a change in elevation is over a horizontal distance. It’s calculated as the change in elevation (the rise) divided by the horizontal distance traveled (the run). This ratio tells you how much elevation changes per unit of distance, and it can be positive (going uphill), negative (going downhill), or zero (flat). Because you’re comparing two lengths in the same units, the slope is a unitless measure of steepness, which is why it’s so useful for comparing different terrains or ramps.

Elevation itself is just a single height above a reference level, not a rate; it doesn’t convey how quickly or slowly the height changes over distance. Stream gradients apply the same idea to water flow, focusing on how much vertical drop occurs over a length of stream, while the Cartesian coordinate system is simply the framework used to plot and compute those elevations and distances. For example, a rise of 6 meters over a run of 3 meters gives a slope of 2, whereas a rise of 6 meters over 60 meters gives a slope of 0.1 (a gentler incline).