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<br />5 <br /> <br />w <br />Cj) <br />CD <br />00 <br /> <br />sediment yield rating ,unit is acre- feet per square mile. <br />This unit can be approximately converted to tons per acre by <br />multiplying the acre-feet per square mile bya factor of <br />three. Each watershed was given a rating of the highest <br />sediment yield category that fell within the watershed. <br />The following rating categories were used in the evaluation: <br /> <br />RATING <br />1 ----- <br />2 ----- <br />3 ----- <br />4 ----- <br />5 ----- <br /> <br />EROSION CATEGORY UNITS (acre~feet/sq. <br />Low ----------~-------- <0.2 <br />Moderate --~----------- 0.2-0.5 <br />Moderately High ------- O.S-l.O <br />High ---~-------------- 1.0-3.0 <br />Very High ------------- >3.0 <br /> <br />mi.) <br /> <br />(7) The Normal Annual Precipitation, 1931-1960, Map of Utah <br />(USDC, NWS, 1960) was used to rate the precipitation ranges <br />that occur within the watershed. This parameter can be used <br />to evaluate the availability of precipitation over the ' <br />watershed for purposes of planning vegetative treatments for <br />rangeland rehabilitation. The greater the ,precipitation, <br />the greater the potential for successful vegetative <br />treatments. The map contains isolines in inches of annual <br />precipitation. The range of precipitation within the <br />watershed area was, recorded. A value of less than eight <br />inches of annual precipitation was determined by the <br />Steering Committee to be the lower limit below which <br />vegetative treatment is impractical. It should be noted <br />that even within 8" to 12" of annual precipitation there is <br />a relatively high risk of failure of vegetative practices. <br />There are mechanical practices that could successfully <br />control overland flow on rangeland with 8" to 12" of <br />precipitation. These practices enhance the potential for <br />vegetative treatment sucoess. The following ratings and , <br />categories were used in the evaluation: <br /> <br />CATEGORY ANNUAL <br />Not ,Recommended <br />Recommended <br /> <br />,PPT. <br /> <br />RATING PRECIPITATION <br />o ----- Veg Treatment <br />1 ----- Veg Treatment <br /> <br />IN. <br /><8 <br />>8 <br /> <br />(8) A Forage condition parameter relating to rangeland <br />condition in relationship to both degree of erosion activity <br />and potential for successful land treatment planning was <br />developed for this inventory. This information was obtained <br />from communication with range conservationists and soil <br />conservationists in BUM and SCS field offices who have <br />responsibility for the individual watersheds being <br />evaluated. This parameter is a subjective rating method but <br />relates to the current resource condition of the rangeland <br />as characterized by range conservationists with field <br />knowledge of the area. A high value in this parameter <br />relates to the need for improved land treatment in the <br />watershed and a low value relates to the watershed being in <br />well managed condition and responding well to current <br /> <br />,~ <br />" <br /> <br />, <br />, <br />'~ <br />