Difference between revisions of "Manning's n"
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Jenny Hill (talk | contribs) (Created page with " <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://...") |
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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> | |||
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!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) | |||
|} | |||
==References== | |||
Latest revision as of 12:55, 5 July 2022
| 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) |
References
- ↑ 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