PROBLEM 2 The following data are from the 2.15-acre watershed W-15, Cherokee, Oklahoma, for the storm of November 16, 1964. Assume that baseflow equals 0 and that all rainfall prior to the start of runoff is an initial abstraction. Determine the distribution of rainfall excess using the o-index method. [Note: Rainfall values give the average intensity over the interval; runoff values are ordinates.] Tips: find the runoff volume by integrating the hydrograph; convert it to depth in cm by dividing by watershed area; use Excel and solver to find the value of so that the volume of the hydrograph is equal to the Time Rainfall (in/h) Time Hydrograph (cfs) Time Hydrograph (cfs) 5:30 0 7:32 0.0000 826 1.1772 6:30 0.01 7:36 0.0030 828 0.9062 7:30 0 7:38 0.0106 830 0.6981 7:45 0.44 7:54 0.0106 834 0.4726 8:00 0.12 7:56 0.0208 838 0.3295 8:05 1.92 7:58 0.0494 842 0.2255 8:10 1.92 8:00 0.0956 900 0.1960 8:15 1.2 8:02 0.1294 910 0.1418 8:20 0.72 8:04 0.2107 920 0.1062 8:25 0.36 8:06 0.2753 930 0.0852 8:30 0.24 8:08 0.4726 940 0.0577 8:45 0.12 8:09 0.7263 950 0.0336 9:00 0.16 8:10 1.0710 10:00 0.0269 9:45 0 8:12 1.4894 10:30 0.0269 9:50 0.24 8:14 1.7495 10:56 0.0208 10:00 0 8:16 2.0313 11:10 0.0106 10:15 0.16 8:17 2.2763 11:30 0.0106 10:35 0.03 8:20 1.8883 12:20 0.0030 8:24 1.4482 13:50 0.0000