Good day,

Applying the Poisson distribution in context of hydrology, is the return period (T) and Annual Recurrence Interval (ARI), more commonly used in hydrology, equal and thus interchangeable and is the following equations therefore correct?

P=1-e^(-t\/T) = 1-e^(-t\/ARI)

T = ARI

Where:

P = probability

t = period of interest

T = is the return period

ARI = Annual recurrence Interval

Is there literature to support this that can be referenced?

Thanks for the time and trouble.