Developing Peak Rate Factor (PRF) Guidance in Hydrologic Modeling

Hydrologic modeling based on the NRCS dimensionless unit hydrograph uses a standard peak rate factor (PRF) of 484, but the method for developing more appropriate PRF values is complex and cumbersome, and is not commonly used. The most current or common Texas practice is to adjust PRF after initial modeling has been performed as a rough calibration to expected values. This current practice lacks guidance and consistency. Further, changes to PRF values have an effect on the peak flow values and resulting sizes for hydraulic structures. Prior research on appropriate PRF values for Texas has been performed in the past, but a relationship of recommended values for varied watersheds and physiographic regions in Texas was not evident at that time. Additional research is needed to build off prior Texas research and establish solid guidance for a range of reasonable PRF values for all areas of Texas. As an effort towards addressing these challenges, researchers will develop a simple, easy–to–use approach for the estimation of peak rate factors and, as needed by the TxDOT, related hydrologic modeling tools.

• Record URL:
  https://library.ctr.utexas.edu/Presto/project=7010

Language

• English

Project

• Status: Completed
• Funding: $154179
• Contract Numbers:

  0-7010

• Sponsor Organizations:

  Texas Department of Transportation

  11th and Brazos Streets
  Austin, TX  United States  78701

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Managing Organizations:

  Texas Department of Transportation

  11th and Brazos Streets
  Austin, TX  United States  78701
• Project Managers:

  Glancy, Chris

• Performing Organizations:

  University of Texas at San Antonio

  One UTSA Circle
  San Antonio, TX  United States  78249
• Principal Investigators:

  Sharif, Hatim

• Start Date: 20190715
• Expected Completion Date: 20200831
• Actual Completion Date: 20200831

Subject/Index Terms

• TRT Terms: Hydraulic structures; Mathematical models; Peak discharge; Water control
• Geographic Terms: Texas
• Subject Areas: Hydraulics and Hydrology; Transportation (General);

Filing Info

• Accession Number: 01714847
• Record Type: Research project
• Source Agency: Texas Department of Transportation
• Contract Numbers: 0-7010
• Files: RIP, STATEDOT
• Created Date: Aug 26 2019 3:16PM