Practice Test Geeks(CFS) Certified Floodplain Surveyor Practice Test
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Surveying Techniques & Data Documentation Flashcards

7 cards from real CFS practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

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  1. A GPS survey for a flood study yields ellipsoid heights. To convert these to NAVD 88 orthometric heights, the surveyor should use:

    Answer: NOAA's GEOID model (e.g., GEOID18) to compute the geoid-ellipsoid separation

    NOAA's GEOID models (currently GEOID18) provide the geoid-ellipsoid separation (N) so that H (orthometric) = h (ellipsoid) − N.

  2. In a HEC-RAS hydraulic model, cross-section station values are measured from which direction?

    Answer: Left to right facing upstream

    HEC-RAS cross-section stations are measured from left to right when facing upstream, following standard hydraulic engineering convention.

  3. Which field documentation element is critical when surveying a bridge opening for a flood study?

    Answer: Low chord elevation, high chord elevation, and roadway profile elevations

    Low chord (soffit), high chord, and roadway profile elevations are essential bridge data for defining hydraulic opening and roadway overtopping potential.

  4. When a surveyor submits an Elevation Certificate, what does Section C document?

    Answer: Flood zone and BFE determination

    Section C of the Elevation Certificate documents the flood zone determination and the Base Flood Elevation (BFE) applicable to the building.

  5. A surveyor performing topographic survey for a FEMA FIRM revision uses LiDAR data as supplemental information. What is a critical limitation of LiDAR in vegetated areas?

    Answer: Vegetation canopy can prevent laser pulses from reaching the ground, causing elevated ground elevations

    In densely vegetated areas, LiDAR pulses may not penetrate the canopy to reach the ground surface, resulting in ground returns that are too high.

  6. What is the standard horizontal datum required for FEMA flood mapping spatial data?

    Answer: NAD 83 (North American Datum of 1983)

    FEMA requires all flood mapping spatial data to be referenced to NAD 83, the current standard horizontal datum in the United States.

  7. During differential leveling, a surveyor reads a backsight of 6.234 ft on a rod held at BM-A (elevation 452.18 ft). What is the Height of Instrument (HI)?

    Answer: 458.414 ft

    HI = Benchmark elevation + Backsight reading = 452.18 + 6.234 = 458.414 ft.