Laserfiche WebLink
<br />Stream and location: <br /> <br />Reach or section: <br /> <br />Event for which n is assigned: <br /> <br />1. Is roughness uniform throughout the reach being considered? <br /> <br />If not, n should be assigned for the average condition of the reach. <br /> <br />2. Is roughness uniformly distributed along the cross section? <br /> <br />Is a division between channel and flood plain necessary? <br />(Channel roughness uses steps 3-13, flood-plain roughness uses <br />steps 14-23). <br /> <br />Is roughness uniformly distributed across the channel? <br /> <br />If not, on what basis should n for the individual segments be <br />weighted? <br /> <br />3. Descr ibe the channel. <br /> <br />Are present conditions representative of those during the flood? <br /> <br />If not, describe the probable conditions during the flood. <br /> <br />4. How will the roughness producing effects of the following on the <br />channel be accounted for? <br /> <br />Bank roughness: <br /> <br />Bedrock outcrops: <br /> <br />Isolated boulders: <br /> <br />vegetation: <br /> <br />Obstructions: <br /> <br />Meander: <br /> <br />Figure 22.--Sample form for computing n values. <br /> <br />(Modified from Aldridge and Garrett, 1973, fig. 4) <br /> <br />42 <br />