Laserfiche WebLink
<br />Peak Discharge. Qp. Peak discharge is calculated internally within the <br />SEDCAD+ program as previously described 1n the SEDCAD+ Calculations <br />portion of the Hydrology section, and 1s considered to be an internal <br />input. <br />Soil Erodibility Factor, K. The majority of the soil types in the Kerr <br />mine area are described as clay loam and sandy loam, therefor from <br />Barfield, et. a1., (1981), Figure 5.5, page 330: <br />K = 0.28 <br /> <br />Representative Slope Length, ~. The slope length is representative of <br />the typical slope length found on the subwatershed and the distance from <br />the point of origin of overland flow until the point that the slope <br />decreases such that significant deposition occurs or until flow enters a <br />defined channel. For the undisturbed areas a slope length of 200 feet <br />was used, and for disturbed areas a slope length of 100 feet was used. <br />Average Slope. The average slope is entered in percent and is the <br />typical or representative slope for overland flow for each subwatershed. <br />Average slope was also measured directly from a 1'500' scale oap on an <br />individual subwatershed basis. <br />Control Practice Factor, CP. The control practice factor is defined as <br />the ratio of sediment loss from an area with a given corer and <br />conservation practice to that of a field in continuous fallow. <br />Using Table 5.5a and 5.5c in the SEDCAD• Users Manual. pages 123 and <br />125: <br />Disturbed Area - assume worst case following topsoil removal <br />therefore rough. Irregular. tracked all directions <br /> <br />CP ~ 0.90 <br />23-70 <br />