|WORLD METEOROLOGICAL ORGANIZATION||
|Explanation of the criteria for classification and numbering of components|| K35.1.04
|Explanation of the dates on the component's description|
COMPUTATION OF WATER-SURFACE PROFILES IN OPEN CHANNELS
1. Purpose and objectives
The technique is used to establish or extend stage-discharge ratings;
to define areas which will be inundated by flood flows of a given frequency; and to compute profiles through various reaches and past control structures.
The standard step-backwater method of computing water-surface profiles is described, the hydraulic principles and assumptions are reviewed, and field data requirements are given. A brief description of the analysis of floodways and the effects of encroachments is also included.
A survey of the geometry of the stream channel along the reach for which the profiles are needed produces the data required: principally cross sections of the channel drawn to a common datum at intervals along the
reach, and the value of the roughness coefficient.
The water-surface profile for any known or assumed discharge.
5. Operational requirements and restrictions
Procedure is not satisfactory on streams with extremely small slopes or very steep slopes.
6. Form of presentation
Manual in English.
7. Operational experience
8. Originator and technical support
U.S. Geological Survey.
10. Conditions on use
|(First entered:25 AUG 87||
Last updated: 20 SEP 88)