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<br />Streamflow Data <br /> <br />The simple forms of the Manning equation shown in equation 1 and 3 <br /> <br />are used only for uniform flow--that is, flow in a channel whose cross- <br /> <br />sectional area does not vary within the reach. The energy equation for <br /> <br />a reach of nonuniform channel between two sections is: <br /> <br />(h+hv)1 = (h+hv)2 + (hf)1.2 + k(6hv)1.2 <br /> <br />(6) <br /> <br />where: <br /> <br />h = elevation above a common datum of the water surface at the <br /> <br />respec~ive section; <br /> <br />h = velocity head at the respective section = aV2/2g; <br />v <br /> <br />a = velocity-head coefficient which is considered to be 1.0 for a <br /> <br />uniformly shaped cross section; <br /> <br />g = acceleration due to gravity = 32.2 feet per second squared <br /> <br />(9.81 meters per second squared); <br /> <br />hf = energy loss due to boundary friction in the reach; <br /> <br />6h = upstream velocity head minus the downstream velocity head; <br />v <br />I <br />k (6h ) = energy loss due to acceleration of velocity or deceleration <br />v <br /> <br />of velocity in a contracting or expanding reach, respectively; and <br /> <br />k = a coefficient equal to ()for contracting reaches and 0.5 for <br /> <br />expanding reaches. <br /> <br />~ <br />0'0 <br />