What term describes the rise in elevation represented as a percentage in relation to horizontal distance?

The term that describes the rise in elevation represented as a percentage in relation to horizontal distance is known as slope. Slope is a key concept in both architecture and civil engineering, as it is used to determine the steepness of a landform or structure. It is calculated by taking the vertical change (rise) divided by the horizontal change (run) and then often expressed as a percentage. This measurement is crucial for various applications, such as drainage design, land grading, and determining accessibility in building design.

The other terms listed do not accurately describe this relationship in the standard terminology used in the field. Elevation ratio, vertical gradient, and gradient index do not have the same accepted definition for expressing slope as a percentage in the context of civil engineering and architectural design. Therefore, slope is the most accurate term in this case. Understanding how to calculate and interpret slope is essential for professionals involved in design and planning, as it impacts both safety and functionality in various projects.