Laserfiche WebLink
<br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br /> <br />Lesson 2 <br /> <br />Basic Hydraulics - Participant Workbook <br /> <br />. USGS. Water-Supply Paper 2339, "Guide for Selecting Manning's <br />Roughness Coefficients for Natural Channels and Flood Plains" <br /> <br />. USGS. Water-Supply Paper 1849, "Roughness Characteristics of <br />Natural Channels", Harry H. Barnes, Jr. <br /> <br />. The n-value assignment is subjective <br /> <br />c. Subdivision n-value Assignment <br /> <br />In order to simulate actual flow conditions and the velocity variations <br />accurately, and to avoid discontinuity in the stage-discharge curve, it <br />usually is necessary to subdivide a cross-section on the basis of <br />roughness elements and geometry. <br /> <br />ROUGHNESS ELEMENT SUBDIVISIONS <br />"'r:r.::I=TATlnN t"!I-IANr.:r:Ii::\ <br /> <br />0.065 <br /> <br />~ <br /> <br />0.038 <br /> <br />tY <br /> <br />w <br /> <br />v <br /> <br />2.30 Roughness Element Subdivisions <br /> <br />ROUGHNESS ELEMENT SUBDIVISION <br />(GEOMETRY CHANGES) <br /> <br />SWITCHBACK <br /> <br /> <br />z <br />o <br />~ <br />> <br />W <br />...I <br />W <br /> <br /> - r <br /> - <br /> ~~ <br /> ~- <br /> [/0 <br />",/ <br /> <br />DISCHARGE <br /> <br />2.31 Roughness Element Subdivision <br /> <br />2.32 Stage-Discharge "Switchback" <br /> <br />2-19 <br />