Laserfiche WebLink
<br />4 <br /> <br />hydraulic parameters of roughness, section constant and hydraulic expo- <br /> <br />nent, which describe the existing stream to which changes are proposed. <br /> <br />Selection of these parameters would then be checked by a calibration run <br /> <br />on the computer, where computer output would be compared to actual con- <br /> <br />ditions observed in the stream. Values of hydraulic parameters would be <br /> <br />adjusted to yield an output which would satisfactorily describe the <br /> <br />unaltered stream. The program could then be used to model any number of <br /> <br />changes in geometry. <br /> <br />~ <br /> <br />Need for the Method <br />The need for stream modeling arises whenever the modification of a <br /> <br />stream channel may possibly affect a third party. Channel modification <br /> <br />may include the installation of such engineering works as dams, bridges <br /> <br />and roadways, or it may ~nvolve stream modification to handle higher <br /> <br />flows diverted from other drainages. Whatever prompts the need for <br /> <br />modifying a channel, the characteristics of flow in a proposed altered <br /> <br />channel must be known as accurately as possible prior to making the <br /> <br />alteration. Knowledge of possible flow behavior in a modified channel <br />not only aids in determining feasibility of a proposed modification, <br />but also assists in identifying areas of possible problems which would <br /> <br />arise due to channel alterations (this may include degradation, <br /> <br />aggradation, high water and meandering). Although computer methods are <br /> <br />available for some problems, the method herein presented extends <br /> <br />application to almost all channel modification problems by providing <br /> <br />ease in modeling geometric changes, an output of usable hydraulic <br /> <br />characteristics and a wide range of application to channels of varying <br /> <br />slope. <br /> <br />, <br />