Final answer:
The Special Flood Hazard Area (SFHA) on FEMA maps represents the high-risk floodplain. The SFHA delineates areas with a significant risk of flooding, and is crucial for insurance and planning purposes.
Step-by-step explanation:
The Special Flood Hazard Area (SFHA) is how the high-risk floodplain is shown on FEMA maps. The correct answer to fill in the blanks would be option a) High-risk. FEMA's Flood Insurance Rate Maps (FIRMs) use SFHAs to indicate areas that are subject to inundation by the base flood, which is the flood having a one percent chance of being equaled or exceeded in any given year, also commonly referred to as the 100-year floodplain. Property owners within an SFHA are typically required to purchase flood insurance if they have a federally backed mortgage.