Annual Recurrence Interval
Calculate Annual Recurrence Interval of Reservoir Spills
This example computes the risk of a pond spilling into a single variable e.g. the annual recurrence interval of spilling from the pond. This variable represents the likeliness that the pond will experience at least a spill in a specific year. As land usage over the catchment feeding the pond will change over time, together with changes in demands on the pond, the various risks (e.g. spilling, being able to maintain a certain level, being able to meet demands) will vary over the years. Computing the risk for each year and over the entire life cycle of the project allows for the identification of specific windows of years where the system might be more at risk than others.
The calculation is illustrated here with a simple modeled system consisiting of a pond being fed by a growing catchment. As the catchment grows, the risk of the pond spilling increases.