ABSTRACT
This chapter covers rainfall data collections and analyses, including time-distribution and mass curve methods for a single rainfall event. When a long-term database is available, the rainfall depth-return period relationship can be determined by frequency analyses using Gumbel, Exponential, Normal, or Pearson Type III distributions. The intensity–duration–frequency (IDF) curve is the best way to preserve the design storm information for engineering applications or/and reproduce the rainfall temporal distributions for stormwater numerical simulations. For flood flow predictions, the rainfall IDF curve provides rainfall depths and intensities for 2- to 100-yr storms. Technical Paper 40 and Rainfall Atlas 14 are introduced to explain how to find the published rainfall statistics for hydrologic designs
