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USE OF SATELLITE REMOTE SENSING TO
STUDY THE EFFECTS OF HURRICANE KATRINA
Research by Dr. Venkat Lakshmi
Department of Geological Sciences
 Hurricane
Katrina flooding impacted many regions for many reasons.
The New Orleans area saw flooding from the ocean surge
while Lake Pontchartrain experienced flooding from the
levee breach. Ocean surge also caused flooding in other
coastal areas of Mississippi and Louisiana. Meanwhile,
the banks of the Mississippi River are extremely wet
from the overflow.
Impacts of major hurricane events such as Katrina and
Rita, while closely studied in coastal and urban
settings, are not as well-understood in agricultural
regions. This study sought to establish a spatial
pattern for damage to agricultural areas from wind and
rainstorms using a variety of multi-spectral satellite
observations.
First, researchers identified areas of hurricane-related
flooding and extreme wetness in northern Louisiana. The
study of wet areas was important as wet areas contribute
to flash flooding, because rainfall does not infiltrate,
but instead runs off and contributes to overland flow.
In the period after the devastation from Hurricane
Katrina, researchers believed any subsequent rain on wet
areas had to be identified because it would cause
localized flooding. Identifying flooded and extremely
wet areas was critical for planning for future
disasters.
Researchers used satellite imagery to quantitatively and
descriptively compare the moisture content and relative
amounts of agricultural biomass before and after the
events. In addition, researchers conducted a case study
near Monroe, Louisiana, to assess the damage to specific
crops because of flooding and strong winds associated
with the hurricanes. Researchers placed an emphasis on
identifying which crops are more at risk because of
geographic location and harvesting cycle. They were also
able to draw comparisons between the land surface in
2005 and the land surface in 2002-2004. Researchers
concluded that areas of low vegetation have greater
wetting and areas of high vegetation have more wind
damage. The erosion of soil would occur from the damaged
vegetation areas.
Researchers believe that this study will help the
federal government better prepare to respond to a
similar-track hurricane in the future. For example,
researchers concluded that the future instrumentation in
hurricane prone-areas should include wind-anemometers.
The study also gave students a good opportunity to
experience site visits to northern Louisiana and see the
correlation between satellite data and the ground. USC
researchers are planning to submit their work for
peer-reviewed publication.Biography
Dr. Venkataraman Lakshmi received his Ph.D. in Civil
and Environmental Engineering from Princeton University
in 1996. He worked at NASA Goddard Space Flight Center
from 1995-1999 and has been at the University of South
Carolina since 1999. His interests include hydrology,
hydrometeorology and hydroclimatolgy, as well as effect
of land surface on ecology and physiology. His studies
are a combination of observations at a field scale,
computer modeling of hydrologic systems, and satellite
remote sensing of the land surface. Research Team/Collaborators:
Christel Lopez, graduate student; Rahul Kanwar,
graduate student. |
