Difference between revisions of "Manning's n"
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|+ Manning's 'n' of vegetated surfaces <ref>Arcement, G.J., Schneider, R. Guide for Selecting Manning's Roughness Coefficients for Natural Channels and Flood Plains U.S.G.S. WATER-SUPPLY PAPER 2339, 1989 http://eh.sdsu.edu/usgs_report_2339.pdf Accessed Dec 19 2017</ref> | |+ Manning's 'n' of vegetated surfaces <ref>Arcement, G.J., Schneider, R. Guide for Selecting Manning's Roughness Coefficients for Natural Channels and Flood Plains U.S.G.S. WATER-SUPPLY PAPER 2339, 1989 http://eh.sdsu.edu/usgs_report_2339.pdf Accessed Dec 19 2017</ref> | ||
|- | |- | ||
! | !'n' value range | ||
!Good condition turf grass | !Good condition turf grass | ||
!Other | !Other |
Revision as of 17:49, 19 December 2017
'n' value range | Good condition turf grass | Other |
---|---|---|
0.002 - 0.010 | Where the average depth of flow is at ≥ 2 times the height of the vegetation | Supple tree seedlings such as willow or cottonwood growing where the average depth of flow is at ≥ 3 times the height of the vegetation |
0.010 - 0.025 | Where the average depth of flow is between 1 - 2 times the height of the vegetation | Moderately dense weeds, or tree seedlings growing where the average depth of flow is from 2 -3 times the height of the vegetation |
0.025 - 0.050 | Where the average depth of flow is about equal to the height of the vegetation | 8- to 10-year-old willow or cottonwood trees inter-grown with some weeds and brush (none of the vegetation in foliage) |
0.050 - 0.100 | Where the average depth of flow is < 0.5 times height of the vegetation | bushy willow trees about 1 year old inter-grown with weeds along side slopes (all vegetation in full foliage) |
- ↑ Arcement, G.J., Schneider, R. Guide for Selecting Manning's Roughness Coefficients for Natural Channels and Flood Plains U.S.G.S. WATER-SUPPLY PAPER 2339, 1989 http://eh.sdsu.edu/usgs_report_2339.pdf Accessed Dec 19 2017