Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School

Civil and Environmental Engineering

First Advisor

Suzette Burckhard


In overland flow water research, travel time is a significant parameter used in estimating peak discharge in channels or rivers. Overland flow is assumed to be in turbulent condition to estimate travel time using Manning’s Velocity Equation (MVE). When the flow is in a laminar condition, Grismer’s Laminar Mean Velocity Equation (GLMVE) is applied but fails to consider the roughness parameter. A review of the literature shows numerous equations for overland travel time, but there is no known equation that determines the mean velocity of overland flow under laminar condition with a roughness coefficient or other coefficient related to the effect vegetation has on the flow. In this study, a new overland flow travel time equation was developed by assuming laminar flow and incorporating Chezy’s vegetation roughness coefficient (��). In this paper, relationships were established between GLMVE and �� and that relationship is used to develop a new travel time equation. The new equation was employed on theoretical models for bare soil, corn growing on the soil, and Bermuda grass growing on the soil. Standard design tables for Darcy’s vegetation roughness coefficient (��) and Chezy’s vegetation roughness coefficient (��) were developed for selected crops at different slopes and crop residues. Validation of the equation was performed by comparing the calculated results for travel time with published data.

Library of Congress Subject Headings

Groundwater flow -- Mathematical models.
Runoff -- Mathematical models.
Fluid dynamics -- Mathematical models.
Transport theory.
Hydrologic models.


Includes bibliographical references



Number of Pages



South Dakota State University



Rights Statement

In Copyright