Determination of Rainfall Losses in Virginia, Phase II: Final Report

Report No: 82-R39

Published in 1982

About the report:

A procedure is presented by which regional unit hydrograph and loss rate parameters are estimated for the generation of design storm hydrographs for watershed in Virginia. The state is divided into seven hydrological regions, and unit hydrograph and loss rate parameters are computed for each region and then related to watershed characteristics such as drainage area, channel slope, etc. The Corps of Engineers’s HEC-I computer program was used to obtain optimal estimates of the Clark unit hydrograph and the standardized exponential loss rate function parameters. A total of 28 test watersheds and more than 160 storm events with corresponding stream flow data were analyzed. Parameter selection curves were developed with the results of the HEC-I analyses.

Disclaimer Statement:The contents of this report reflect the views of the author(s), who is responsible for the facts and the accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of the Virginia Department of Transportation, the Commonwealth Transportation Board, or the Federal Highway Administration. This report does not constitute a standard, specification, or regulation. Any inclusion of manufacturer names, trade names, or trademarks is for identification purposes only and is not to be considered an endorsement.


Other Authors

James Cruise, Shaw L. Yu

Last updated: January 20, 2024

Alert Icon

Please note that this file is not ADA compliant. Choose one of below options: