Overland Flow Resistance Estimation from Small-Plot Data

by Saeed M. Jorat, Los Angeles Dep of Water and Power, Los Angeles, United States,
Tim J. Ward, Los Angeles Dep of Water and Power, Los Angeles, United States,

Document Type: Proceeding Paper

Part of: Management of Irrigation and Drainage Systems: Integrated Perspectives


The correct application of physical process models, such as the kinetic wave approximation to shallow overland flow, is dependent upon selection of appropriate values for parameters which are present in the models. In overland flow models, the most difficult parameter to select is resistant to flow. Most models require either a Manning's n or a Darcy-Weisbach f value. This paper reports on the use of small plot (1m × 1m) rainfall simulator data to estimate resistance to flow for upland watersheds. Field and laboratory studies are compared. Cover density was found to be the most significant plot characteristic for estimating resistance. Laboratory experiments supported the observed phenomena of increasing then decreasing resistance as Reynold's number is increased. Models for estimating resistance based on the field and laboratory experiments are presented.

Subject Headings: Flow resistance | Load and resistance factor design | Overland flow | Computer models | Physical models | Watersheds | Rain water | Flow simulation | United States | Arizona | New Mexico

Services: Buy this book/Buy this article


Return to search