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<br />7 <br /> <br />t\) <br />to <br />~ <br />1;>) <br /> <br />word for the percentage rating of each item. This allows the <br />rater to document and consider the relative value of each item in <br />terms of sediment yield. These items could be important in <br />determining FWOP conditions and FWP proposed land treatment <br />measures. The vegetation, litter and rock ratings should be made <br />in the field by direct observation and paced transect. Each item <br />should be rated to the nearest five percentage point value. This <br />eliminates developing arguable digit ratings and relates to the <br />sensitivity level of the -10. to +10 rating system (see below). <br /> <br />The percentage rating of effective ground cover is made by <br />totaling the percentages of vegetation, litter and rock. An <br />Effective Ground Cover rating chart is included in the Revised <br />PSIAC Rating Sheet. <br /> <br />. . <br />In developing the FWP and FWOP conditions, the. modelling of the <br />Ground Cover (f) factor is critical. The increase of litter and <br />vegetation should be estimated from experience in previous type <br />of treatments or rated by example in the field if a.previously <br />treated area is available. . <br /> <br />Modification 12: It is proposed that the Land Use (g) rating <br />factor be re-evaluated. The cultivated land factor should be <br />removed from rating consideration. If cropland is present within <br />a geomorphic unit; for instance, it cannot be assumed that <br />because 50% of the area is cultivated that a necessarily high <br />sediment yield rating i~ deserved. The sediment yield rating of <br />cultivated cropland should be characterized by the USLE procedure <br />(or other appropriate model) and a sediment delivery ratio should <br />be applied for complete characterization. <br /> <br />The term "intensively grazed" should be removed as a rating <br />criterion. Good management and a properly implemented grazing <br />plan can allow an area to be intensively grazed without <br />appreciable increases in sediment yield. There may be.on-site <br />gross soil disturbance but this problem affects productivity, .not <br />sediment yield. The f.actor that should be considered in this <br />context is the quality of grazing management. The following <br />terminology is proposed for the high, moderate and low rating <br />categories. The 10 point category line (b) should read "Almost <br />all the area overgrazed or historical overgrazing impacts are <br />still wide spread.". overgrazing implies management problems and <br />historical overgrazing implies former management problems that <br />have not been accounted for in recent management. In the 0 point <br />category line (c) should read "Less than 50% of area overgrazed <br />or historically overgrazed.". The -10 point category line (c) <br />should read "Good .grazing practices in effect or historic <br />overgrazing damage controlled by present land use practices.". <br /> <br />The 10 point category should be augmented to reflect road <br />construction quality in regard to potential sediment yield and <br />road drainage. Gravel (dirt) or unimproved roads are common in <br />the intermountain region. Roads can significantly contribute to <br />sediment delivery or significantly contribute to sediment yield <br />