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<br />the Environmental Protection Agency (EPA), HEC-l developed by the U.S. Army <br /> <br />Corps of Engineers, and the Colorado Urban Hydrograph Procedure (CUHP) which <br /> <br />uses the Snyder unit hydrograph concept. Other synthetic unit hydrographs <br /> <br />include Clark, Snyder and the SCS dimensionless unit hydrographs. <br /> <br />All of these methods will estimate flood flow frequency magnitude. Some <br /> <br />are more desirable depending on future use because they will furnish <br /> <br />additional information about storm runoff volume, time to peak, runoff-time <br /> <br />distribution, ease of hydraulic ro~g ~icjtions. <br />~z. ~.. <br />The stream gaging method uses the reco~s obtained at gaging stations. <br />It <br /> <br />The stream gaging methods may also incorporate statistical methods to improve <br /> <br />the estimations of discharge. The statistical methods include a probabilistic <br /> <br />distribution of peak flows and computation of mean, standard deviation and <br /> <br />skew of the data Linder consideration. They may <br /> <br /> <br />extrapolation of <br /> <br />data from nearby stream gages, either upstr <br /> <br />designated hydrologically similar. The aw data <br /> <br />flood frequency magnitudes using the Log Pearson Type III distribution by <br /> <br />government agencies as recommended by the Water Resource Council in Bulletin <br /> <br />l7B (US Water Resources Council, 1981, Guidelines for Determining Flood <br /> <br />Frequency, Bulletin #17B of the Hydrology Committee.) The most obvious <br /> <br />drawback to this method is that the more data available the better the <br /> <br />results, and if there are less than 10 years data the/~erults are question;Ab e <br />~~~-k-~ ' <br />,~!~~X~~A~~~W~f /:ri~esi)Tr,,:p;ll~andled y ~. <br />2?~he develoP~;nt~f ~g~~ion analYSi~~here by equations weFe-~ <br />developed for direct estimation of peak flows with basin drainage variables. <br /> <br />The appropriateness of selected variables with in the general regression <br /> <br />equation is analyzed statistically. Index-flood equations have been used to <br />1\ <br /> <br />7 <br />