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<br />14 <br /> <br />The step methods available for general water surface profile <br /> <br />. <br /> <br />solution include the Geological Survey Step Method, Leach's Method, Corps <br /> <br />. <br /> <br />of Engineers Methods 1 and 11, and Bureau of Reclamation Methods A and <br /> <br />B. The Geological Survey Step Method is applicable when the flow is <br /> <br />contained in a relatively uniform channel and all portions of the flow <br /> <br />will travel the same distance between adjacent sections. Solution of <br /> <br />. <br /> <br />the energy equation, with appropriate deductions for frictional and eddy <br /> <br />losses, can then be carried step-wise from station to station. The <br /> <br />equation used is similar to that of the direct step method, except that <br /> <br />terms are included which allow larger changes in velocity due to cross- <br /> <br />section changes. The equation is written as: <br /> <br />, <br /> <br />v2 <br />Z <br />az - + d2 + Zz <br />2g <br /> <br />v2 <br />] <br />= Ctl - + <br />2g <br /> <br />d] + Z] + friction loss + other losses <br /> <br />. <br /> <br />dl <br /> <br /> orlzonta I Line <br />- <br /> Energy SI <br /> OPe " Sf hf = <br /> Water Surface Slope =S <br /> w , <br />- Ch <br /> <br />H <br /> <br />iT <br /> <br />T <br />VZ <br />I <br />2g <br /> <br />I <br /> <br />Sf Llx <br /> <br />2 <br />Vz <br />2g <br /> <br />t- <br /> <br />. <br /> <br />-4-. <br />CD <br /> <br />annel e t ' dz <br />o tOm S Ll <br />Ll x . So 0 ~ <br />D't"m~ <br />o <br /> <br /> <br />ZI <br /> <br />. <br /> <br />Fig. 2-3. Channel reach for solution by the Direct Step Method <br />