A comparative evaluation of surface runoff models and methods on small developing watersheds in Northern Virginia

Increasing populations in urban regions have prompted the development of areas previously undisturbed. This development has spurred the formation of numerous models and methods to simulate the effects of urbanization on runoff processes. The engineer who must use these models and methods needs to be aware of their capabilities and performance. Many of the models assume that calibration will take place to improve the final results. Unfortunately, this is not the case for the majority of drainage studies. A qualitative and quantitative evaluation is made to help the engineer decide which model or method is applicable in certain situations. Simulations are performed on eight watersheds in northern Virginia. Nineteen models are evaluated and compared to gaged events as well as calibrated design storms. The models include EPA SWMM, PSRM-QUAL, TR-20, HEC-1, TR-55, variations of the rational method, three-unit hydrograph procedures, the USGS regression equations, and the Anderson method. Coverage is given for all of the models to outline their capabilities. Hydrographs are evaluated with respect to peak flow, time to peak flow, time base, volume, and overall shape. Statistical measures are introduced to quantitatively test the modeled hydrograph to a baseline reference hydrograph. The statistics yield many errors with the models being evaluated. A selection criteria is given where the models may be chosen based on their performance. The table is limited to the range of watersheds evaluated. Trends in each model toward basin area, land use condition, and general model type are discussed. A cross-calibration technique for improving the accuracy of some models is verified.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Civil Engineering

Department dc:contributor.department

Civil Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

1993

Author dc:creator

• Small, Aaron Brent

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Dc Identifier Other

etd-03302010-020635

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/41876