
131Water-Related Losses
in a ooded basement in the upstream side basement of a house. For those types of cases, the
watershed upstream needs to be determined along with the design of the culvert.
e probability that a ooding event will occur in a particular year is given by
P
=
1
(5.52)
e probability of an event occurring in n years is
P
n
=− −
11
1
(5.53)
where
P is the probability of the event
I is the event
For example, the probability of a 100-year ood occurring in 1 year is, from Equation 5.52, 1%.
e probability that a 100-year ood will occur in 20 years can be calculated from the following
equation:
P =− −
=11
1
18 2
20
Precipitat ...