COMMISSION

Table 1. Percentage of Bare Ground and Vegetated Cover 2002-2014
Year Bare Ground (%) Vegetated (%)
2002 27.5 72.5
2009 41 59
2014 29 71
Image Classification Analysis
Both park staff and a consulting firm that has been coordinating the General Plan,
conducted analysis using ArcGIS of the 2002, 2009, and 2014 aerials for vegetation cover.
The Image Classification toolbar within the ArcGIS software was utilized to analyze the land
classes of vegetated (showing low reflection) and bare ground (showing high reflection). The
SVRA created land classification maps for each aerial and then quantified the classifications
to obtain a general quantified acreage for vegetation and bare ground in the park.
Aerial Point-Intercept Analysis
Using field methodology for point-intercept studies (Herrick et al. 2005), staff converted
the protocol for use with aerial photography. Six point count sites within the riding
area of the park were randomly selected. The aerial imagery was zoomed in on each
point and 250-foot buffers were created surrounding the point. Using a compass, four
directional points were randomly chosen to create four transect lines. By utilizing multiple
methodologies as well as different analysts, staff obtained an objective and accurate
portrayal of the vegetative cover at Prairie City SVRA. Aerial point-intercept analysis and
image classification analysis provided percent cover for the entire SVRA, with both methods
obtaining 70 percent vegetative cover for 2014. The image classification of the riding
acreage of the SVRA produced a vegetative cover of 64 percent for 2014. Moving forward,
staff plan to continue conducting aerial imagery analysis whenever aerials can be flown,
including conducting vegetative cover analysis in each individual zone.
Staff from the State Parks Roads and Trails Program assisted with an analysis of the 2002
and 2009 aerials. The results depicted a net loss of 55.5 acres of vegetation between 2002
and 2009. The full protocol can be seen in Appendix C of the 2013-2014 Habitat Monitoring
System Report Prairie City and Clay Pit SVRAs (Heitner and Cumber-Lose, 2013/2014
HMS Report 2014, 71-72). A consultant helped produce an analysis of the 2002, 2009, and
2014 aerials. Table 2 shows the breakdown of vegetation and bare ground in the riding
area. This analysis showed a loss of 26 acres of vegetation between 2002 and 2014.
2017 Program Report 159