Ottawa RiverRegulationPlanning BoardCommission de planificationde la régularisationde la rivière des Outaouais



A type of statistical representation of a value in terms of percentages.  For example, the 25th percentile is the value below which 25% of historical flows or levels are found, and above which 75% are found.

probability of occurence

The chance or likelyhood that an event will happen over a period of time.