What is return period - and what it does NOT say

Engineers use the return period often to convey the probability of some variable (e.g. rainfall, flood) exceeding a given value in a given year. It is the average period between events, the return period involves the idea of periodicity, which can mislead non-experts. This is NOT an explanation of the statistical methods we use to derive extreme value distributions (e.g. fitting an extreme value distribution like Gumbel, Fréchet or Weibull), but a conceptual explanation of the concepts. The database shown in this video is here: https://er.srv.pathirana.net The spreadsheet (using Microsoft Excel) is available here https://asselapathirana.github.io/dra...