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<br />in size from about 0.5 to 15 mP; they are recommended in preference to previous- <br />ly developed methods for estimating flood characteristics on small ungaged basins <br />in this region. To improve estimates for sites at or near gaging stations where <br />flood-frequency information is available, equations given by Sauer (1974) or <br />McCain and Jarrett (1976). are recommended. <br /> <br />Table 4.--Summary of equations for estimating the characteristics of flood <br />flows from small rural watersheds in the Arkansas River basin <br /> <br />Peak discharge (Q ) in cubic <br />p <br />0,5- to 3.0-square-mile <br /> <br />500A 0.89 <br />Q10 = E <br /> <br />840 0.97 <br />Q2 5 = AE <br /> <br />=1 140 1. 01 <br />Q50 ' AE <br /> <br />=1 550 1. 07 <br />Q100 ' AE <br /> <br />feet per second, <br /> <br />basins: <br /> <br />(Se =41.1)J <br />(Se=40,l) <br />(Se=40,2) <br />(Se=34,O) <br /> <br />3.0 to 15.0-square-mile basins: <br />= 830A 0.41 <br />Q10 E <br /> <br />=1 560 0,44 <br />Q25 ' AE <br /> <br />=2 280 0.47 <br />Q 50 ' AE <br /> <br />Q =2,930A 0.50 <br />100 E <br /> <br />(Se=48.6) <br />(Se=39.8) <br />(Se=35,4) <br />(Se =29,7) <br /> <br />Flood volume (v), in acre-feet <br />V=O,141QpO.919 <br /> <br />(S =62) <br />e <br /> <br />Synthetic hydrograph constants: <br />feet per second per discharge <br />per time unit~ <br />Q' =Q160 <br /> <br />T' =0. 748V/ Q' <br /> <br />discharge constant (Q'), in cubic <br />unit; time constant (T'), in minutes <br /> <br />lAverage standard error of estimate, in percent, <br />2Dimensionless hydrograph time and discharge units, and an example <br />application of the synthetic hydrograph procedure, given in table 5. <br /> <br />25 <br />