Rainfall Intensity-Duration Frequency (IDF) curves

Rainfall Intensity-Duration-Frequency (IDF) curves are graphical tools that show how much rain is likely to fall over different durations (like 5 or 60 minutes) at various chances of occurring in a year (such as once every 2, 10, or 50 years). They help engineers and planners design drainage systems by predicting heavy rainfall events, ensuring infrastructure can handle these events without flooding. Essentially, IDF curves provide a way to understand the relationship between how intense rain is, how long it lasts, and how frequently such events happen.