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. ~ <br />whereas the vegetation type on the undisturbed areas is primarily <br />mountain shrub and sage with more canopy than ground contact. <br />To illustrate this point, the operator provided the following <br />demonstration using the USLE to compare estimated soil losses <br />between the reclaimed and undisturbed areas: <br />The Universal Soil Loss Equation (USLE) is given as: <br />A = RKLSCP <br />where: A = computed soil loss/unit area (tons/acre) <br />R = rainfall factor <br />K = soil erodibility (tons/acre - R unit) <br />LS = length slope factor (dimensionless) <br />C = cover factor (dimensionless) <br />This demonstration assumes that C is the only variable between the <br />reclaimed and undisturbed areas. Therefore, R, K and LS are <br />constant between the two: <br />R = 26 <br />K = .27 <br />LS = 9 <br />The cover factor, C, is then calculated separately for the <br />reclaimed and undisturbed areas. From baseline vegetation studies, <br />the total ground cover in the undisturbed area is 65.1%. Of the <br />65% ground cover in the undisturbed area, 55% is canopy cover, and <br />only loo contacts the ground surface. <br />Using the table provided on page M-12F of the permit application <br />package (PAP), we see that, for cover by broadleaf, herbaceous <br />plants with 10% ground contact, shrubs with a 0.5 m fall height <br />have a C factor of 0.26, whereas shrubs with a 2 m fall height have <br />a C factor of 0.34. Interpolating between the two, the estimated <br />C factor for the undisturbed area is 0.30. <br />In the reclaimed area, total ground cover is between 58% and 630. <br />Of this, 50% is in contact with the ground surface with no <br />appreciable canopy. For 40% ground contact and no appreciable <br />canopy, the C factor is given as 0.10, and for 60°s ground contact <br />with no appreciable canopy, the C factor is given as 0.042. <br />Interpolating between the two, the C factor for 50s ground contact <br />with no appreciable cover is estimated to be 0.071. <br />Plugging these values into the USLE with the constant factors <br />described above, the sediment loss for the undisturbed area is <br />approximately 12.32 tons/acre/year and for the reclaimed area is <br />2.91 tons/acre/year. This demonstrates that the reclaimed areas <br />appear to be significantly more effective in controlling erosion <br />than the undisturbed areas due to the higher soil retention <br />characteristics of the grass cover as compared with the original <br />shrub cover. <br />