Precipitation and Hydrologic Design

This lecture focuses on methods to define the design storm for a given location and precipitation duration. It covers statistical analyses of precipitation data, empirical methods, Weibull plotting position, and probability distributions for precipitation extremes. The instructor explains the Weibull plotting position, empirical distribution of rainfall maxima, Gumbel distribution, and estimating its parameters. The lecture also discusses the areal distribution of precipitation, spatial reduction factor, intensity-duration-frequency relationships, and parameterizations of IDF curves. It concludes with examples of rainfall intensity maps and how to relate return period to rainfall depth.