A river like the Mississippi is no less regular than the Nile in its tendency
to flood. The flood of 1993 was unusual in that it reached well beyond the "100-year flood" level.
Now that the flood of 1993 has come and gone, does that mean there won't be a flood of this size
on the Mississippi for another 99 years? Not at all. This year and every year, there's a one
percent chance that it could happen again.
A river like the Mississippi is no less regular than the Nile in its tendency
to flood. The flood of 1993 was unusual in that it reached well beyond the "100-year flood" level.