For a flood of return period of 50 years, the risk of the flood is given by (for 10 years),
[Take \({\left( {\frac{{49}}{{50}}} \right)^{10}} = 0.817\) , \({\left( {\frac{{48}}{{50}}} \right)^{10}} = 0.665\)]
1
12.1%
2
76.2%
3
83.2%
4
18.3%
For a flood of return period of 50 years, the risk of the flood is given by (for 10 years),
[Take \({\left( {\frac{{49}}{{50}}} \right)^{10}} = 0.817\) , \({\left( {\frac{{48}}{{50}}} \right)^{10}} = 0.665\)]