Flood Prediction

Question 1

How do you calculate the recurrence interval (years)?

Answer 1

No. of years on record + 1 / ranking of flood being considered (in terms of flood size in m3s-1)

Question 2

What is the flood return period?

Answer 2

When the recurrence interval is plotted against discharge as a scatter graph, you can use the line of best fit to predict when the next flood of a particular altitude may occur.

Question 3

What floods should densely populated areas be protected against?

Answer 3

1 in 100 year flood events

Question 4

What data do hydrologists use to forecast floods?

Answer 4

River discharge records in relation to precipitation, and flood recurrence interval graphs.