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<br />CVR = SR/XR = 0,1213 <br /> <br />(5) <br /> <br />se = 0.0354 <br /> <br />GR = 0,38 <br /> <br />(6) <br /> <br />se = 0.45 <br />Xs = 0.892 log A + 3.229 log E - 2.060 <br />. <br /> <br />(7) <br /> <br />r2 = 0.80 <br /> <br />se = 0.213 <br /> <br />CVS = SS/XS = 0.0618 <br /> <br />(8) <br /> <br />se = 0.0275 <br /> <br />GS = 0.11 <br /> <br />(9) <br /> <br />se = 0,33 <br /> <br />where the subscripts Rand S refer to rain and snowmelt events, respec- <br />tively, and <br /> <br />A = drainage area, in square miles, <br /> <br />E = mean watershed elevation, in 1,000 feet, <br /> <br />CV = coefficient of variation, <br /> <br />G = skew coefficient of logarithms, <br />S = standard deviation of logarithms, <br />X = mean logarithm of peak flow, <br />r2 = coefficient of determination, <br /> <br />se = standard error of estimate. <br /> <br />For any ungauged site in the region with given drainage area and mean <br />watershed elevation, Equations 4 through 9 were used to compute the statisti- <br />cal parameters which define the flood frequency curve for each type of event <br />by Equation 1. These two frequency curves were then statistically combined <br />using equation (3) to obtain the final frequency curve for the un9auged site <br />being considered. Figures 6 through 11 depict the regression lines and data <br />points for the statistical parameters, Figure 12 shows frequency discharge <br />curves for a specific drainage area of 213 square miles and mean watershed <br />elevations at l,OOO-foot intervals above 7,000 feet. The composite curve in <br />each case is derived graphically by statistically combining the probabilities <br /> <br />15 <br />