2009-09-21_PERMIT FILE - C1981010A (44)

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• • Table 4.4-3. "C" Factors for permanent pasture and rangeland. (1) Veaetative 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 .45 ,20.. . .,10.. .042 .013. ' :::003 : W .45 .24 .15 .090 .043 .. .011 Canopy of tall forbs ' . . 25 : . 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 .08 .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 A7 .12 .077 .040 .011 Trees but no. appre-: 25 .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. [HBHfjb 5/87 Retyped 5/96] • 4-107 Revision: 72-7 1 Approved: 2119199