2005 Hurricane Damage Extends
to Projects Intended to Heal Nature
Beyond their incalculable damage to
the Gulf Coast, last year’s hurricanes
had consequences that are just now being
realized. By an irony of nature, at least
one project intended to help heal nature
was obliterated by nature itself.
Before he joined our firm, GIS Specialist
Chris Zeitner analyzed Gulf Coast
wetlands for the National Oceanic and
Atmospheric Administration (NOAA) as
part of a project that was outdated overnight.
Alabama, Florida, Louisiana, Mississippi,
and Texas are home to the largest
areas of coastal wetlands in the country.
Thanks in large part to human activity
along the Mississippi, these wetlands are
disappearing at the alarming rate of 50
acres a day. In reaction, NOAA instituted
the Coastal Change Analysis Program
(C-CAP), which used remote sensing and
GIS technologies to monitor the total net
gain or loss of coastal wetlands throughout
the country.
...one project intended to help heal nature was obliterated by nature itself.
In spring 2004, C-CAP began using
the Landsat 7 satellite to map the wetlands
on the Gulf Coast. The satellite collected
multi-spectral imagery and beamed it to a
data center in South Dakota, which sent
it to Chris and his project team colleagues
in Portland for analysis. The imagery,
which looked something like infrared
photos, consisted of pixels, with each pixel
corresponding to a spot on the ground.
Images were collected for leaf-off (winter)
and leaf-on (spring and summer). The
project team used the bandwidths of the
images to differentiate between wetland
classes and vegetated and non-vegetated
surfaces. Part of the project involved field
visits to the Gulf Coast to ground-truth
the project team’s classifications. These
were compared to classifications for previous
studies to determine the net gain/
loss of coastal wetland. By summer 2005,
the team had completed data analysis and
mapping, giving NOAA a powerful and
descriptive tool for analyzing wetland loss
throughout the Gulf Coast region so that
the areas in most need of wetland restoration
could be identified.
Then Katrina and Rita intervened and
filled many wetlands with silt and debris.
The hurricanes made the data and maps
created by C-CAP obsolete just months
after their creation. At this point, NOAA
and C-CAP are incorporating the 2005
pre-hurricane landcover data into the
2001 landcover data to accurately track
historical changes to the coastal wetlands.
NOAA will also use the 2005 data to analyze
those areas inundated by the storms
as a baseline for post-hurricane mapping.
Chris Zeitner is a GIS Specialist for JD White, a division of BERGER/ABAM Engineers Inc..
Email Chris to see how GIS can be used in your next project.
This article was originally published in the White Report, on June 2006.
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