2004 
N 2 
A q 5 5 
C. 
nd 
is, 
N 
on 
S 
ain 
of 
ral 
"he 
eir 
ind 
292 
VEGETATION MODELING, ANALYSIS AND VISUALIZATION 
IN U.S. NATIONAL PARKS 
Marguerite Madden 
Center for Remote Sensing and Mapping Science (CRMS), Dept. of Geography 
The University of Georgia, Athens, Georgia 30602, USA - mmadden (@cerms.uga.edu 
Commission IV, Working Group IV/6 
KEY WORDS: GIS, Analysis, Visualization, Aerial Photographs, Vegetation, Landscape 
ABSTRACT: 
Researchers at the Center for Remote Sensing and Mapping Science (CRMS) at The University of Georgia have worked with the - 
U.S. Department of Interior National Park Service (NPS) over the past decade to create detailed vegetation databases for several 
National Parks and Historic Sites in the southeastern United States. The sizes of the parks under investigation vary from Everglades 
National Park and Big Cypress National Preserve in south Florida (10,000 km?) and Great Smoky Mountains National Park located 
in the Appalachian mountains of Tennessee and North Carolina (2.000 km”) to small national battlefields and historic sites of less 
than 100 ha. Detailed vegetation mapping in the parks/historic sites has required the combined use of Global Positioning System 
(GPS), softcopy photogrammetry and geographic information system (GIS) procedures with digital elevation models (DEMs) to 
construct large scale digital orthophotos and vector-based vegetation databases. Upon completion of the vegetation databases, 3D 
visualization and spatial analyses were conducted and rule-based models constructed to assist park managers with a variety of 
environmental issues such as terrain influence on vegetation, fire fuel assessment and vegetation patterns related to interpreter 
differences and human influence on vegetation. 
1. INTRODUCTION 
The Center for Remote Sensing and Mapping Science 
(CRMS) at The University of Georgia has worked 
cooperatively with the National Park Service (NPS) over the 
past decade to create digital vegetation databases for 17 
National Park units of the southeastern United States 
(Madden et al, 1999; Welch et al, 1995; 1999; 2000; 
2002a). In all of these parks, overstory vegetation detail was 
interpreted and compiled from large- and medium-scale color 
infrared (CIR) aerial photographs (1:12,000 to 1:40,000- 
scale). In one park, Great Smoky Mountains National Park, 
an understory vegetation database also was compiled using 
leaf-off aerial photographs of 1:40,000 scale. The method of 
photo rectification varied from simple polynomial solutions 
in relatively flat areas such as the Everglades in south Florida 
to full photogrammetric solutions, aerotriangulation and 
orthorectification in high relief areas such as the Great 
Smoky Mountains National Park (Jordan 2002; 2004). 
In order to accommodate the complex vegetation patterns 
found in national parks, classification systems suitable for 
use with the aerial photographs were created jointly by 
CRMS, NPS and NatureServe ecologists (Madden et al., 
1999; Welch et al., 2002b). These classification systems are 
based on the U.S. Geological Survey (USGS)-NPS National 
Vegetation Classification System (NVCS) developed by The 
Nature Conservancy. (TNC) (Grossman et al, 1998). 
Extensive Global Positioning System (GPS)-assisted field 
investigations also were conducted to collect data on the 
vegetation communities and correlate signatures on the air 
photos with ground observations. Based on this field work, 
manually interpreted vegetation polygons were attributed 
with NVCS classes to create vegetation databases in 
Arc/Info, ArcView and ArcGIS formats, depending on the 
time the database was developed and the size of the park. 
1287 
Upon completion of the vegetation databases, geographic 
information system (GIS) analyses were conducted to assist 
park managers with a variety of environmental issues. 
Specific objectives of this paper include: 1) demonstrate GIS 
analysis of the Great Smoky Mountains National Park 
overstory vegetation database for assessing environmental 
factors related to vegetation distributions; 2) utilize rule- 
based modeling techniques to assess forest fire fuels and fire 
risk; and 3) examine vegetation patterns using landscape 
metrics to address interpreter differences, human influences 
and hemlock distributions threatened by exotic insects. 
2. GIS ANALYSIS OF OVERSTORY VEGETATION 
The analysis of environmental factors such as terrain 
characteristics that are associated with each forest 
community type provides national park botanists with 
information that can be used to better understand, manage 
and preserve natural habitats. A portion of the Great Smoky 
Mountains National Park database, namely the area 
corresponding to the Thunderhead Mountain (THMO) 7.5- 
minute USGS topographic quadrangle, was selected for 
assessing vegetation and terrain characteristics (Fig. 1). 
Overlay analysis of vegetation polygons with elevation range 
and slope provided mean, range and variance statistics that 
can be associated with individual forest and shrub classes 
(Fig. 2 and 3). Overlay analysis of vegetation polygons with 
aspect indicated the probability of locating forest community 
types in particular microclimates controlled largely by 
aspect. (Fig. 4). For example, cove hardwood forests prefer 
moist environments and are found mainly on north, northeast 
and northwest aspects, while xeric oak hardwoods are found 
predominantly on south, southeast and southwest facing 
slopes.