What is a Temporary Benchmark (TBM) typically used for in surveying?

• A. Providing a permanent point of reference for future surveys
• B. Marking changes in land use over time
• C. Setting a semipermanent point of known elevation
• D. Calculating the area of land accurately

Answer: (C)

A Temporary Benchmark (TBM) is typically used in surveying to establish a semipermanent point of known elevation. This point is essential for various surveying tasks, as it aids in creating a level surface from which measurements can be accurately taken. TBMs are often set up during the course of a survey project and are used for reference during the period in which surveying is actively taking place.

These benchmarks provide a reliable elevation reference that can be utilized in future measurements within the project area, allowing surveyors to maintain consistent height references. It's important to note that while a TBM serves an essential function during a project, it is meant to be temporary and may not be maintained indefinitely like a permanent benchmark. Its primary role revolves around aiding in height determination rather than serving as a long-term reference for future survey endeavors or for tracking land use changes, which are associated with different types of surveying practices.