Final answer:
An elevation reference mark on a Flood Insurance Rate Map (FIRM) is represented by a small black cross or dot. It is used to show the location and elevation of a certain point on the map.
Step-by-step explanation:
An elevation reference mark on a Flood Insurance Rate Map (FIRM) is represented by a small black cross or dot. It is used to show the location and elevation of a certain point on the map. The mark allows users to determine the height above mean sea level of different areas on the map.
For example, a dot inside a circle is often used as the elevation reference mark on a FIRM. The dot represents the location on the map, while the circle indicates the elevation value associated with that location.
Elevation reference marks are essential for determining flood risk, as they help assess the potential for flooding in different areas based on their elevation.
On a Flood Insurance Rate Map (FIRM), an elevation reference mark typically looks like a small circle or square with a number inside or beside it, indicating the elevation above sea level at that location. These marks are critical when assessing flood risks and determining floodplain boundaries. The elevation reference mark is used by surveyors, city planners, and engineers to ensure accurate terrain and elevation data for various projects, including construction and urban planning.