Photographic guidance for selecting flow resistance coefficients in high-gradient channels

Yochum, S.E., Comiti, F., Wohl, E. , David, G.C.L. and Mao, Luca (2014) Photographic guidance for selecting flow resistance coefficients in high-gradient channels. Technical Report. Rocky Mountain Research Station.

Full content URL:

rmrs_gtr323.pdf - Whole Document

Item Type:Paper or Report (Technical Report)
Item Status:Live Archive


Photographic guidance is presented to assist with the estimation of Manning’s n and Darcy-Weisbach f in high-gradient plane-bed, step-pool, and cascade channels. Reaches both with and without instream wood are included. These coefficients are necessary for the estimation of reachaverage velocity, energy loss, and discharge. Using data collected in 19 stream channels located in the State of Colorado and the Eastern Italian Alps, on slopes ranging from 2.4 to 21 percent, guidance is provided for low through bankfull flows. Guidance for low flow resistance estimation is additionally provided using data collected in 29 channels in the State of Washington, New Zealand, Chile, and Argentina. Bankfull n values range from 0.048 to 0.30 and low flow n values range from 0.057 to 0.96. Discussions of flow resistance mechanisms and quantitative prediction tools are also presented.

Additional Information:Official website: You may send email to to request a hard copy of this publication
Subjects:F Physical Sciences > F820 Geomorphology
Divisions:College of Science > School of Geography
ID Code:32718
Deposited On:23 Jul 2018 14:47

Repository Staff Only: item control page