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-5- <br />• a scale of 1" = 400': <br />1. Grassland (pasture) <br />2. Upland sagebrush <br />3. Agricultural (alfalfa meadows) <br />4. Juniper <br />5. Riparian <br />6. Farmstead (i.e., ranch house and ancillary facilities) <br />7. Disturbed (i.e., roads and current mining operation) <br /> Each mapping unit within the approximately 106 acre study area was delin- <br />• i <br /> eated on a reproducible mylar image of the aerial photograph pr <br />or to <br /> collection of field data. Ground truthing of type delineations took <br /> place during field sampling. For affected areas, each randomly located satr <br /> ple point was transferred to a topographic base map by measuring from obvious <br /> larxhTarks. Each sample point thus represented a ground truth location and <br /> allowed efficient and accurate field ground truthing of affected area <br /> type delineations. Ground truthing of type delineations over the rest of <br /> the study area was accomq~lished by field spot checking at selected locations. <br /> Once the prel~m~na.y vegetation map was ground frothed for accuracy and <br /> corrected, all correct vegetation type delineations were transferred to <br /> a 1" = 400' topographic base map. Thus, the distortion associated with <br /> aerial photographic mosaics was eliminated in the final vegetation map <br /> by transferring all information to the correct topoyraphic base map. Acre- <br /> ages of each mapping unit were determined by standard polar plani~ter <br /> tecYuiiques applied to the final topographic base map. To ensure accurate <br /> acreage determination, each mapping unit was measured twice (or more if <br /> measurements varied by more than 58) and the average used to aurq~ute <br />• <br /> acreages . <br />