- Coastal Flood Boundaries - additional help and further information
- Where can I access the Coastal Flood Boundaries data and guidance documents?
- How is sea level rise accounted for in the Coastal Flood Boundaries?
- I am concerned about the large differences in values in some locations and the effects on my project
- Levels have fallen in my area of interest since the previous Coastal Flood Boundaries update. How can this be when sea levels are known to be rising?
- What has changed in Coastal Flood Boundaries 2018?
- I’ve been given mean high water springs (MHWS) and highest astronomical tide (HAT) predicted Tide Levels by another source. They don’t match up to those in the Coastal Flood Boundaries. Which should I use?
- How are levels within ‘Inland Extensions’ or ‘Estuaries’ derived?
- How should I use Coastal Flood Boundaries levels in estuaries and tidal rivers?
- What are the key outputs of Coastal Flood Boundaries 2018?
- What has been done to update the Coastal Flood Boundaries in 2018?
- Why are regular updates, and therefore likely change in the estimates, necessary?
- How often is the Coastal Flood Boundaries dataset updated?
- How can I generate my Base Tide Curves?
- Are waves included in the Coastal Flood Boundaries?
- What information is included in the extreme sea levels shapefiles?
- What is the accuracy of the Coastal Flood Boundaries extreme sea levels?
- What is the vertical datum of the Coastal Flood Boundaries Level?
- What is the base year for Coastal Flood Boundaries levels?
- What is meant by Annual Exceedance Probability (AEP) and which extreme sea level probabilities are included?
- How does the Coastal Flood Boundaries inform us about flood risk around the UK coast?
- Who should use the Coastal Flood Boundaries (CFB) data?
- What are the Coastal Flood Boundaries?
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.