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Irrigated Pasture - 2007 Cover Data <br />The vegetation data is from the report 2007 Vegetation Sampling for Phase 2 Bond <br />Release: Irrigated Pasture and Dryland Pasture. <br />0.1% Noxious Weeds <br />0.2% Annual Forbs <br />57.6% Perennial Grasses <br />27.7% Perennial Forbs <br />11.1 % Litter <br />Ground Cover (cover that contacts the surface) = Annual forbs + Perennial Grasses + Litter <br />+ Noxious Weeds <br />Ground Cover = 69% <br />Canopy Cover = Perennial Forbs <br />Canopy Cover = 27.7% <br />Using Table 3 and a canopy of 25% (short brush 0.5 meter in height) and the "G" canopy <br />type, the chart of Figure 2 was developed. From this chart, a ground cover that contacts the <br />surface of 69% yields a "C" factor of 0.025. Since the actual canopy is 27.7%, another <br />chart was developed from the data in Table 2 showing the change in "C" factor versus % <br />ground cover for a canopy of 50%. This is Figure 3, and using a ground cover that contacts <br />the surface of 69%, gives a "C" factor of 0.026. Since the actual canopy is 27.7%, a <br />simple interpolation is required to give the correct "C" factor: <br />0 "C" for canopy 25-50 = A "C" for canopy 25-27.7 <br />25 2.7 <br />0.001 = x x z 0.0001 <br />25 2.7 <br />Therefore, the best "C" value for the post-mine irrigated pasture is 0.025 + 0.0001 = <br />0.0251 <br />23