About Canute - the Sea Level Calculator
Canute provides estimates of the likelihood of future flooding from the sea. By combining two uncertainties (the frequency of present storm surges and the uncertainty of future sea-level rise) into a single likelihood, a statistically robust prediction is generated.
Canute allows you to select your location of interest from over 12,000 datapoints at roughly 2.5km resolution around the whole Australian coastline via a map interface. You then select a future greenhouse gas emission scenario and your time period of interest. The tool calculator will then output a graph indicating the probability of experiencing at least one flooding event during this period (red line) for a range of design heights. For comparison an equivalent probability curve for conditions of constant sea level (set at the value for the year 2000) is also plotted (blue line).
For each selection, the tool provides the output in two ways:
1. As the exceedance probability for each level or height. This is presented in two ways: with linear and stretched probability scales. Either of these may used for reading the exceedance probability, but the second form is generally easier because the resultant curve is almost straight.
2. As the expected number of flooding events over the period (future enhancement, shortly to be released).
For the estimation of risk, the second form of output is generally recommended, because it gives an estimate of the actual number of flooding events. The first form (the exceedance probability) only gives the probability that a given level will be flooded at least once; it therefore gives no information on the likely number of flooding events during the period.
As an example, a simple risk assessment may be performed by estimating the cost of a single flooding event and multiplying it by the expected number of flooding events at a given level.
Canute now comes with a range of additional features:
- A wave setup and runup calculator.
- Shoreline recession calculators.
- Storm-surge climatologies
A number of further enhancements to Canute 2 are programed for the coming year.
To access Canute register and complete the online training here
Review a case study which uses the outputs from Canute here
In situations where there is a soft shoreline it will also be important to address the likelihood of coastal recession due to sea-level rise. Canute currently has two shoreline recession calculators version 1 and version 2. In addition the following websites provide useful information on this topic.
http://www.ozcoasts.org.au/climate/ (OzCoasts Climate home page)
http://www.ozcoasts.org.au/coastal/ (Landform and stability mapping)
http://www.ozcoasts.org.au/indicators/beach_erosion.jsp (Beach erosion)
http://www.tasmarc.info/ (The Tasmanian Shoreline Monitoring and Archiving Project)