1998-02-18_PERMIT FILE - C1981010A

• Permit No: C1981010A
• IBM Index Class Name: Permit File
• Doc Date: 2/18/1998
• Section_Exhibit Name: 4.4 Rangeland
• Media Type: D
• Archive: Yes

Table 4.4-3. "C" Factors for permanent pasture and rangeland. (1)
Vegetative Canopy Cover That Contacts the Surface
Canopy
Type and Height Cover(3) Total Percent Ground Cover
Of Raised Canopy (2) % Type (4) 0 20 40 60 80 95-100
Column No. 2 3 4 5 6 7 8 9
No appreciable canopy G .46 .20 .10 .042 .013 .003
W .45 .24 .15 .090 .043 .011
Canopy of tall forbs 26 G .36 .17 .09 .038 .012 .003
or short brush W .36 .20 .13 .082 .041 .011
(0.5m fall ht.) 50 G .26 .13 .07 .035 .012 .003
W .26 .16 .11 .075 .039 .011
75 G .17 .10 .06 .031 .011 .003
W .17 .12 .07 .067 .038 .011
Appreciable brush 25 G .40 .18 .09 .040 .013 .003
or brushes W .40 .22 .14 .085 .042 .011
(2m fall ht.) 50 G .34 .16 .085 .038 .012 .003
W .34 .19 .13 .081 .041 .011
75 G .28 .14 .08 .036 .012 .003
W .28 .17 .12 .077 .040 .011
Trees but no appre- 25 G .42 .19 .10 .041 .013 .003
ciable low brush W .42 .23 .14 .087 .042 .011
(4m fall ht.) 50 G .39 .18 .09 .040 .013 .003
W .39 .21 .14 .085 .042 .011
75 G .36 .17 .09 .039 .012 .003
W .36 .20 .13 .083 .041 .011
(1) All values shown assume: (1) random distribution of mulch or vegetation, and (2) mulch of
appreciable depth where it exists.
(2) Average fall height of waterdrops from canopy to soil surface: m = meters.
(3) Portion of total-area surface that would be hidden from view by canopy in a vertical projection, (a
bird's-eye view).
(4) G: Cover at surface is grass, grasslike plants, decaying compacted duff, or litter.
W: Cover at surface is mostly broadleaf herbaceous plants(as weeds with little lateral-root network
near the surface, and/or undecayed residue).
From: Soil Conservation Service, USDA, 1982. A Guide for Predicting soil Loss from Water Erosion in
Colorado. Tech. Note 50. Table 6.
IHBHfjb 5/87 Retyped 5/96I
4-107
Revision: -72-:7
Approved: 41151l'%