POTENTIAL EFFECTS OF TRANSLATORY WAVES ON ESTIMATION OF PEAK FLOWS. TECHNICAL NOTE

On August 19, 1971, a severe thunderstorm just outside Wikieup, Arizona, produced one of the largest known flood peaks for a 49.2-square-km drainage basin. Initial calculations of the peak discharge assumed stable flow conditions and a four-section slope area measurement revealed that discharge was 2,082 m3/s. Recent findings based on free-surface instability characteristics at the locale suggest that gravitational forces exceeded boundary retarding forces, and flow in the wide sand channel was unstable. Calculations for roll or translatory waves indicate that waves hit the highway bridge at velocities of as high as 12.5 m/s. Close agreement between free surface instability results, translatory wave calculations, estimates of the steady flow on which the translatory waves traveled, and an eyewitness report of the translatory waves suggest that the total peak discharge could have been 2,742 m3/s or 32 percent greater than the published discharge. The occurrence of translatory waves in natural channels may in fact be far more common than originally thought, and instability criteria should be considered for hydraulic analysis of flow in steep smooth channels.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/oclc/8672558
• Corporate Authors:

  American Society of Civil Engineers

  345 East 47th Street
  New York, NY  United States  10017-2398
• Authors:
  • Hjalmarson, H W
  • Phillips, J V
• Publication Date: 1997-6

Language

• English

Media Info

• Features: Appendices; Figures; References; Tables;
• Pagination: p. 571-575
• Serial:
  • Journal of Hydraulic Engineering
  • Volume: 123
  • Issue Number: 6
  • Publisher: American Society of Civil Engineers
  • ISSN: 0733-9429
  • Serial URL: https://ascelibrary.org/journal/jhend8

Subject/Index Terms

• TRT Terms: Calculation; Floods; Flow; Free surface; Hydraulics; Peak discharge; Thunderstorms; Unsteady flow; Velocity
• Uncontrolled Terms: Flow velocity
• Old TRIS Terms: Computations; Translatory waves
• Subject Areas: Highways; Hydraulics and Hydrology; I26: Water Run-off - Freeze-thaw;

Filing Info

• Accession Number: 00737566
• Record Type: Publication
• Files: TRIS
• Created Date: Jun 19 1997 12:00AM