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<br />" <br /> <br /> <br /> <br />8 <br /> <br />N <br />~ <br />~ <br />~ <br /> <br />criterion. Good management and a properly implemented grazing plan <br />can allow an area to be intensively grazed without appreciable <br />increases' in sediment yield. There maybe on-site gross soil <br />disturbance but this problem affects productivity, not sediment <br />yield. The factor that should be considered in this context is the <br />quality of grazing management. The following terminology is <br />proposed for the high, moderate and low rating categories. The 10 <br />point category line (b) should read "Almost all the area overgrazed <br />or historical overgrazing impacts are still wide spread.". <br />Overgrazing implies management problems and,historical overgrazing <br />implies former management problems that have not been accounted for <br />in recent management. In the 0 point category line (c) should read <br />"Less than 50% of area overgrazed or historically overgrazed."., <br />The -10 point category line (c) should read "Good grazing practices <br />in effect or historic overgrazing damage controlled by present land <br />use practices.". <br /> <br />The 10 point category should be augmented to reflect road <br />construction quality in regard to potential sediment yield and road <br />drainage. Gravel (dirt) or unimproved roads are' common in the <br />intermountain region. Roads can significantly contribute to <br />sediment delivery or significantly contribute to sediment, yield <br />control depending on construction, design and maintenance. The <br />rating line should read "Roads in need of maintenance or need <br />drainage control design.". :, Excessive concentrated road, drainage <br />can lead to' significant' gullying and damaging concentrated flow' <br />erosion. If road bank erosion is significant, it can be, <br />characterized by the direct volume method (USDA,SCS, 1983). <br /> <br />In the 10 point and 0 point categories there' should be items. <br />inVOlving the badlands land type. The 10 point rating line should <br />read "Almost all of the area is badlands with minimal armoring.". <br />The 0 point'rating line should read "almost all of the area is <br />'badlands with 50% armor on'slopes.". Badlands is a land type that <br />is not accounted for in the PSIAC (1968) procedure.' Not all <br />badlands are in a high yielding condition. For instance the Book <br />Cliffs region of Utah is a badlands escarpment, composed of a <br />sandstone caprock underlain by hundreds of feet of highly erosive <br />Mancos Shale on steep slopes. The sediment yield from the Book <br />Cliffs varies greatly with the amount of natural armoring that has <br />occurred from the weathering of the overlying sandstone caprock. <br /> <br />Based on the above discussion, it is proposed that this category be <br />renamed LAND TYPE AND MANAGEMENT QUALiTY. This change is necessary , <br />because badlands is a land type (not a use), wildfire burned areas <br />are a management problem with high sediment yield rates (not a land <br />use) and grazing, overgrazing, historic overgrazing, logging and <br />roads relate to sediment yield in terms of land management (not as <br />a land use). <br /> <br />Modification 13: It is proposed that in the Upland Erosion (h) the <br />reference to rill erosion be eliminated and replaced with the term <br />