Which statement best differentiates depth-damage curves from exposure maps in flood risk assessment?

• A. Depth-damage curves model expected damage by flood depth for assets, while exposure maps show where assets are located and their value, used together for risk estimation.
• B. Exposure maps predict flood depth using LiDAR data.
• C. Depth-damage curves indicate only the timing of flood events.
• D. Exposure maps are used solely for marketing and do not relate to risk.

Answer: (A)

Depth-damage curves capture how much damage a given asset sustains as flood depth increases. They translate a flood depth scenario into expected losses for that asset type, reflecting how vulnerability grows with deeper flooding. Exposure maps, on the other hand, show where assets are located and how valuable they are, providing the spatial and economic context needed for risk estimation. When you combine the two, you can estimate total risk by applying the depth-damage curve to the flood depth at each asset location and summing the resulting damages across all assets. This pairing is what allows you to move from a physical flood scenario to an estimated financial impact.

The other statements miss essential aspects: exposure maps do not predict flood depth themselves (that relies on hydrodynamic modeling and elevation data, not just mapping assets); depth-damage curves relate depth to damage, not the timing of events; exposure maps are not solely for marketing but are central to assessing risk by showing what is exposed and how valuable it is.