In surveying, what does the term "benchmark" refer to?

The term "benchmark" in surveying refers to a reference point of known elevation. Benchmarks are critical in establishing elevations and serve as a point of reference for various surveying and construction activities. These stationary markers have been precisely surveyed and their elevation accurately measured, making them reliable points for determining the altitude of other points. When a surveyor needs to establish a level plane or compare the elevation of different locations, they will often refer back to a benchmark.

In practice, benchmarks are often used in topographic surveys, engineering projects, and construction, as they provide a consistent frame of reference. This allows surveyors to ensure accuracy and reliability in their elevation data, which is especially important in larger projects where variations in elevation can significantly affect design and construction decisions. Therefore, understanding benchmarks and their application is essential for anyone involved in surveying or related fields.