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International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV , Part B7. Istanbul 2004
examining tree densities in images collected over 51 years. In
this study, no time-trend was observed, suggesting that if it is
occurring at all, desertification is slower than previously
thought in the Sahel. A range of ecological problems become
tractable with the possibility of locating ad identifying
individual trees by remote sensing. At one end of the
spectrum is the detection of rare individuals, genotypes, or
species and at the opposite end of the spectrum is the
location and identification of individual trees of a common
species in a diverse community of similar species. A forester
may have a particular interest in detecting the presence of rare
survivors of a disease or insect pest outbreak in order to find
resistant individuals. For example, many field ecologists have
observed occasional large American chestnut individuals that
have reached reproductive size and age despite exposure to
ubiquitous chestnut blight. It may be that 99 percent of such
cases can be due to chance escape from the blight, but 1
percent can be due to genetically-based resistance. Detection
of a large enough sample of reproductive chestnuts to
perform genetic screening could be impossible without an
extensive search procedure such as that provided by remote
sensing.
The identification of species resisting to different stress
conditions has direct forestry and agriculture applications.
The ability to identify vegetation at the species level using
hyperspectral data has been difficult because of lack of
information on vegetation characteristics and biochemical
characterization of vegetation at canopy level (Martin and
Aber, 1997).
There have been many studies comparing spaceborne and
airborne multispectral ^ imagery. However, similar
comparisons could not be done for hyperspectral sensors
until the successful lunch of the Hyperion sensor.
The main objective of this study was to compare
hyperspectral remotely sensed data collected by the
Hyperion satellite, and the airborne Real-time Data
Acquisition Camera System (RDACS-3) and the Airborne
Visible/Infrared Imaging Spectrometer (AVIRIS) for
environmental mapping and vegetation species identification.
2. STUDY AREA
The study area is located in the Land-Between-the Lakes
(LBL) (Figure 1) National Recreation Area, which was
designated in 1991 as an International Biosphere Reserve
under the Man and Biosphere Programme of the United
Nations Education, Scientific and Cultural Organization
(UNESCO). In addition to LBL, the Reserve includes 17
surrounding counties in Kentucky and Tennessee as the area
influenced economically, socially and environmentally by the
management of LBL. One of the main purposes of the
Biosphere Reserve Programme is to "involve industry,
government, social agencies, schools, and special interest
groups in management of the Reserve" and to encourage
cooperation in studying and solving regional problems. The
1307
draft Environmental Impact Statement for LBL identified
more than 20,000 acres to be designated as core areas in the
preferred management alternative. The remainder of the
170,000 acres of LBL serves as the buffer zone with the 17-
county area is the transition zone. Many research studies
concerning LBL and Kentucky Lake have been conducted at
Murray State University in the last 30 years; some of which
provided useful information for this research.
LBL is approximately 90 percent forested, which makes it
one of the largest contiguous blocks of forested land east of
the Mississippi River in the US. Ferguson Spring/Energy
Lake site has been selected as a research site because of its
diverse ecology including wetland and bottom land/upland
forest. The dominant forest species are oak and hickory.
Oak and hickory trees requiring large amounts of sunlight
when they are seedlings have been the dominant overstory
tree species in LBL. Forest composition of LBL would shift
toward maple and beech trees, which prefer shade if it is left
completely unmanaged. Maple trees do not produce nuts
that wildlife can feed on maple seeds are small and winged.
This would negatively impact many different wildlife species,
including deer, squirrel, songbirds, and wild turkey, which for
thousands of years have fed on the acorns and nuts of
oak/hickory forest of LBL. Table | summarizes some of the
overstory species found in LBL.
AUTRES diva s
Figure 1. Location map of the study area and the datasets
The Center for Reservoir Research (CRR) was established in
1987 by the Kentucky Council on Higher Education as a
Center of Excellence for Teaching and Research. CRR
research has been focused mainly on Kentucky Lake water
monitoring and the Kentucky Lake GIS (KLGIS). One of the
principal programs of CRR is the Kentucky Lake Long Term
Monitoring Program (begun in July, 1988), which
encompasses 17 primary monitoring sites on the lower 30 km
of the lake. The KLGIS database providing a better
evaluation of the forest and wetlands in the area include
bathymetry, cultural features, geology, groundwater,
hydrography, soils, terrain, water quality and wetland data
for the Kentucky Lake drainage basin.
