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<br />DRAINAGE CRITERIA MANUAL <br /> <br />RAINFALL <br /> <br />2. RAINFALL DEPTH-DURATION-FREQUENCY <br /> <br />. <br /> <br />2.1 Rainfall Depth-Duration-Frequency Maps <br />Using the information contained in the NOAA Atlas (I), <br />Depth-Duration-Frequency maps were prepared for the Denver Region. <br />presented for the I-hour and 6-hour durations for the 2-, 5-, 10-, <br />100-year recurrence frequencies as Figures 2-1 through 2-10. <br /> <br />Rainfall <br />MipS lire <br />50-, and <br /> <br />2.2 Depths For Durations Between One- and Six-Hours <br />Rainfall depths for durations between one and six hours can be found with <br />the help of Figure 2-11, "Precipitation Depth-Duration Diagram", provided in <br />this section. The use of Figure 2-11 is explained in 2.1.2 "Example: <br />Development of a Depth-Duration-Frequency Table". <br /> <br />2.3 Example: Development Of A Depth-Duration-Frequency Table <br />Develop a table of rainfall depths for the 1-, 2-, 3-, and 6-hour <br />durations at the 2-, 10-, and 100-year recurrence frequencies at T3S, R66W <br />within the UD&FCD boundaries. <br />From the Rainfall Depth-Duration-Frequency Maps, Figures 2-1 through 2-10, the <br />following depths, in inches, are obtained: <br /> <br />. <br /> <br /> I-hour 6-hour <br />2-year 0.95 1.40 <br />10-year 1.60 2.23 <br />laO-year 2.60 3.40 <br /> <br />The above 1- and 6-hour depths are plotted as shown on Figure 2-12. The <br />depths at 2- and 3-hours are then interpolated on Figure 2-12 and a table of <br />rainfall depths is compl~ted for the desired recurrence frequencies and <br />durations as follows: <br /> <br /> I-hour 2-hour 3-hour 6-hour <br />2-year 0.95 1.11 1.22 1.40 <br />10-year 1.60 1.83 1. 99 2.23 <br />100-year 2.60 2.88 3.08 3.40 . <br /> <br />5-1-84 <br />