January 13, 2004
D. M. Fitzgerald, G. A. Zarillo & S. Johnston
ig. 20. Photo mosaic of the central Florida Sebastian Inlet area created by rectifying to a USGS
digital ortho-image using the ArcViewTM. Beachtools GIS extension.
Figure 20 is a photo mosaic of the central Florida coast in the vicinity of Sebastian
Inlet created by rectifying digitized aerial photography against a regional ortho-
image database. Figure 21 shows the details of the vegetation line and shoreline
extracted within the GIS platform using image analysis methods. Also shown are
a series of cross-shore transects automatically placed along the shoreline at a user
specified interval, allowing quantification of shoreline position. Figure 22 illustrates
the possibility of a power spectrum analysis using the high-resolution data extraction
that is available using the capabilities of GIS.
Image analysis of common aerial photography has also been under-utilized in
examining tidal inlet dynamics. The INLETGIS extension to ArcViewTM 3. was
developed to automate many of the steps involved in shoal and channel change
analysis using aerial imagery (Connell and Zarillo, 2003). The result is a tool that
facilitates rapid data turn-around, less subjectivity, and a gentle learning curve, thus
serving users with a broad range of scientific and engineering backgrounds in need
of a rapid, objective image analysis tool.
Inlet morphology classification can be based on spectral reflectance pattern
recognition. For example, the classification shown in Fig. 23 was applied to the water
and shoal portions of a digital historical photoset of a tidal inlets to determine where