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  4. What is meant by Annual Exceedance Probability (AEP) and which extreme sea level probabilities are included?

What is meant by Annual Exceedance Probability (AEP) and which extreme sea level probabilities are included?

Created: 03 October 2019 Updated: 03 October 2019

The Coastal Flood Boundaries (CFB) includes 16 probabilities of extreme sea level ranging from 100% to 0.001% AEP (or 1 to 10,000 year return periods).

Annual Exceedance Probability (AEP) describes the likelihood of being exceeded in any given year. For instance, an AEP of 1% has a chance of being exceeded 1 in 100 in any given year. In coastal design the reciprocal of an AEP is often termed as a ‘return period’. An AEP of 1% is equivalent to a return period of 100 years.