The files linked to this reference are the geospatial data created as part of the completion of the baseline vegetation inventory project for the NPS park unit. Current format is ArcGIS file geodatabase but older formats may exist as shapefiles. A digital vegetation map for GARI was developed as a personal geodatabase using Environmental Systems Research Institute (ESRI) ArcGIS software. The geodatabase includes a point feature class for locations of plots and two polygon-feature classes (clipped by the park boundary and unclipped) for vegetation, including non-vegetated land cover. The vegetation map includes 31 map classes. Upland communities comprise about 86% of the park area and are represented by 13 map classes. Two upland map classes each include patches of two associations, all others represent single associations.

The files linked to this reference are the geospatial data created as part of the completion of the baseline vegetation inventory project for the NPS park unit. Current format is ArcGIS file geodatabase but older formats may exist as shapefiles. The final MNRR vegetation map consists of 3,590 polygons totaling 69,011 ac (27,928 ha). Mean polygon size is 12.1 ac (4.90 ha). Of the total area, 37,789 ac (15,293 ha) or 55% represent natural or ruderal vegetation map classes. Agricultural vegetation such as cultivated crops and pasture account for approximately 6,238 ac (2,524 ha) or 9% of the total mapped area. Non-vegetated barren land was rare, only accounting for 45 ac (18 ha) or 0.1%. Developed areas such as open mowed fields, parking lots, buildings, and others account for approximately 1,562 ac (632 ha) or 2%. Open water is the most widespread land cover class, with an area of approximately 23,422 ac (9,479 ha) or 34% of the total mapped area. Within the total area occupied by vegetation map classes, forest and woodland types were the most extensive (17,007 ac (6,882 ha) or 46%), followed by herbaceous types (11,457 ac (4,636 ha) or 31%), sparse types (6,287 ac (2,544 ha) or 16%), and shrubland types (3,038 ac (1,229 ha) or 7%).

The files linked to this reference are the geospatial data created as part of the completion of the baseline vegetation inventory project for the NPS park unit. Current format is ArcGIS file geodatabase but older formats may exist as shapefiles. Following the vegetation plot data analysis, the preliminary vegetation map was edited and refined to produce a revised preliminary vegetation map prior to thematic accuracy assessment. Using ArcMap 9.2 (ESRI 1999-2006), polygon boundaries were revised on screen based on the plot data, field observations, classification analyses, aerial photography signatures, and topographic maps. Each polygon was assigned the NVC Community Element Global (CEGL) code of a preliminary vegetation association based on the information sources listed above. Second, third, and fourth CEGL code choices were entered in cases of uncertainty, or for polygons representing mosaics of two or more types.

The files linked to this reference are the geospatial data created as part of the completion of the baseline vegetation inventory project for the NPS park unit. Current format is ArcGIS file geodatabase but older formats may exist as shapefiles. The TOP 2015 imagery was mosaiced and manipulated using image processing and segmentation techniques (e.g. unsupervised image classification, normalized difference vegetation index, etc.) to highlight any subtle vegetation signature differences. All of the preliminary results were evaluated for usefulness and the best examples were first converted to digital lines and polygons, were next combined with other relevant AMIS GIS layers (such as the roads network), and the results were used as the base layer for the new AMIS vegetation mapping effort. Building off the base layer, all relevant lines and polygons were exported as shapefiles and converted to ArcGIS coverages. The resulting coverages were run through a series of smoothing routines provided in the ArcGIS software. Following the smoothing, all digital line-work was manipulated to remove extraneous lines, eliminate small polygons, and merged polygons that split obvious stands of homogeneous vegetation. The cleaning stage was considered complete when all resulting polygons matched homogenous stands of vegetation apparent on the TOP 2015 imagery. At this point, the mapping shifted to manual techniques and all vegetation lines and polygons were visually inspected and manually moved, edited and/or updated as needed.

The files linked to this reference are the geospatial data created as part of the completion of the baseline vegetation inventory project for the NPS park unit. Current format is ArcGIS file geodatabase but older formats may exist as shapefiles. All of the interpreted and remotely sensed data were converted to Geographic Information System (GIS) databases using ArcMap© software and are included in a comprehensive geodatabase. Draft maps created from the vegetation classification were field-tested and revised before independent ecologists conducted an assessment of the map’s accuracy during 2014.

The files linked to this reference are the geospatial data created as part of the completion of the baseline vegetation inventory project for the NPS park unit. Current format is ArcGIS file geodatabase but older formats may exist as shapefiles. Mapping began in earnest in 2007 by re-sampling the 2002 imagery to a 3-meter pixel resolution and then segmenting it using eCognition software. Initial segments were created to delineate obvious landforms (e.g. open water and fields) and physiognomic features (e.g. grasslands versus woodlands). Following segmentation, the lines were exported as ArcInfo shapefiles and converted to ArcInfo coverages. The resulting coverages were run through a series of smoothing routines until no obvious artificial or relict breaks in the lines were visible. Following smoothing, the line-work was manually cleaned to remove extraneous lines, small polygons, and polygons that obviously split a homogenous stand of vegetation.

The files linked to this reference are the geospatial data created as part of the completion of the baseline vegetation inventory project for the NPS park unit. Current format is ArcGIS file geodatabase but older formats may exist as shapefiles. GRBA’s spatial database and map layer was produced from high-resolution 2007 Digital Map, Inc. imagery provided to CTI by the NPS. By comparing the signatures on the imagery to field and ground data, 64 map units (48 vegetated, four barren geology and snow, and 12 land-use / land-cover) were developed and the vegetation map units were directly cross-walked or matched to their corresponding rUSNVC plant associations. The interpreted and remotely sensed data were converted to Geographic Information System (GIS) spatial geodatabases and maps were printed, field tested, reviewed, and revised.

The files linked to this reference are the geospatial data created as part of the completion of the baseline vegetation inventory project for the NPS park unit. Current format is ArcGIS file geodatabase but older formats may exist as shapefiles. The map was designed to facilitate ecologically- based natural resources management at a 1:24,000 scale with 0.5-ha minimum map unit size. Based on a provisional assessment, overall accuracy was 82.5% for Level 1 and 66.8% for Level 2. Level 1 units will likely be sufficient and most appropriate for many natural resource planning and evaluations, while Level 2 units provide added fine-scale information within major ecological groups. To support the map as a management tool, we provide an annotated map legend along with descriptions of each plant association, a corresponding diagnostic key, field forms, and a plant species list. The map was delivered in both printed form and as digital Geographic Information System (GIS) map files. The GIS format allows flexibility to update the map as new information becomes available, or as major vegetation changes, such as fire, disease or other impacts, occur in the park.

The files linked to this reference are the geospatial data created as part of the completion of the baseline vegetation inventory project for the NPS park unit. Current format is ArcGIS file geodatabase but older formats may exist as shapefiles. October 29, 1996: Aerial photography for Rock Creek Park is flown February 25, 1997: Initial meeting at Rock Creek Park headquarters - acquisition of aerial photography and ancillary data including existing vegetation maps March - April 1997: First cut delineations onto aerial photography of the photo signatures (see Figure 3 - Rock Creek Park Photo Index). May 12 - 16, 1997: Photointerpretation field reconnaissance trip, TNC training of park biologists in field sampling methodology May - June 1997: Develop initial list of photo signature types, Revise initial delineations based on field reconnaissance findings, Label existing polygons with photo signature types, Deliver copies of overlays to park biologists for plot selection and feedback June - September 1997: Park vegetation sampling effort February 19, 1998: Received draft TNC report of the vegetation classification for Rock Creek March 1998: Received final TNC report on the vegetation classification for Rock Creek, Received plot data and locations for vegetation sampling effort, Received TNC key for communities, Development of PI signature / TNC community lookup table, Polygons attributized with initial communities April 1998: Received DOQQ files (April 1989) May 11-12, 1998: Photointerpretation field verification trip May 1998: Revise photo signature / TNC community lookup table, Update and correct PI community calls and PI linework June - October 1998: Data rectification and conversion, Interim files and plots delivered to NPS-ROCR, Final documentation

The files linked to this reference are the geospatial data created as part of the completion of the baseline vegetation inventory project for the NPS park unit. Current format is ArcGIS file geodatabase but older formats may exist as shapefiles. Several imagery sources were used to derive the vegetation map, primarily Light Imaging and Detection Radar (LiDAR) and aerial imagery from the National Agriculture Imagery Program. The eCognition software package and Berkley Imaging Segmentation was used to create the initial image segments and polygon map. The mean values of variable inputs were summarized for each of the training data polygons and were used to generate a predictive non-parametric model using RandomForest in the statistical program R. The model was then applied to all polygons. The resulting draft map was reviewed by experts familiar with the vegetation types of the area. The final map includes 24 classes, representing 3 land cover types and 21 alliance-based map classes. A field-based, blind random sample accuracy assessment of the map was carried out in mid-August 2011 and December 2011. A total of 175 accuracy assessment points were collected. Based on the assessment, the total map accuracy was 88.9%, exceeding the program standard of 80%.