Published By National Park Service, Department of the Interior
Issued about 9 years ago
Summary
Description
This point file displays the 500 accuracy assessment (AA) points visited in July and August of 2004 as part of the vegetation mapping project. Five hundred and one accuracy assessment points were created for COLM (2 were inaccessible) by Keith Landgraf and Steve Blauer of the USGS-RMMC. The points were randomly selected, stratified by the map units used for vegetation mapping and further screened so as not to fall on inaccessible isolated mesa tops and vertical canyon walls. The coordinates were uploaded to Garmin hand-held GPS receivers so that ecologists could navigate to them in the field. Some AA points fell on ecotones and two sets of data were recorded on the evenly-split site. AA points that fell along polygon edges sometimes did not represent the entire polygon well and some AA points fell on small patches of vegetation that were different than the community in the larger area. Many recently dead Pinus edulis trees were present on the landscape and would appear on the 2002 aerial photos as living. Notes were taken to support these observations during the AA point evaluation phase of the project. For all AA data collection, whenever an unknown species was encountered, a sample was collected and keyed to accurately establish its identity. In addition to collecting vegetation data, photographs were taken at each location visited -- approximately 1,000 images were acquired to illustrate the AA sites visited.