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Prof. Mahta Moghaddam |
Jane Whitcomb |
Mapping of wetlands in the entire state of Alaska was accomplished for the
first time under the direction of
Prof. Mahta Moghaddam using radar remote sensing. The process for
generating the wetlands map was described in the article,
Mapping Vegetated Wetlands of Alaska Using L-Band Radar Satellite Imagery,
by graduate student Jane Whitcomb, Prof. Mahta Moghaddam, researchers from
JPL, Kyle McDonald and Erika Podest, and Josef Kellndorfer from The Woods
Hole Research Center. This article, published in the Canadian Journal of
Remote Sensing, vol. 35, no. 1, pp. 54-72, February 2009, was selected
as the Best Published Paper in the journal for the year 2009. [Additional
Information]
It is believed that the direct impacts of global warming will be most
strongly felt in the Earth’s high latitudes in various forms. Wetlands, in
particular, are among the most vulnerable ecosystems, which can act as both
major sinks and sources of atmospheric greenhouse gases depending on the
warming trends and their feedbacks. However, the locations, types, and sizes
of northern wetlands are not accurately known; it is difficult to identify
and classify wetlands because they are often located in remote and
hard-to-access places, they span very large regions (25% or more in Alaska
and Canada), and appropriate remote sensing data and analysis techniques
have not been available until now.
This paper describes a method for continental-scale mapping of northern
wetlands using L-Band synthetic aperture radar (SAR) from space. Using the
“Random Forests” statistically based decision tree algorithm along with
training and testing data compiled from the National Wetlands Inventory (NWI)
and the Alaska Geospatial Data Clearinghouse (AGDC), the first
high-resolution synoptic wetlands map of Alaska was generated at the
University of Michigan. This wetlands map provides an initial basis for
improved characterization of land-atmosphere CH4 and CO2
fluxes and climate change impacts associated with thawing and inundated
soils and changes in the size of wetland ecosystems.
Using this method, large-scale boreal wetlands can be mapped and tracked
over time, offering important insights into climate change and a
quantitative input into global climate models.
Posted: May 25, 2010 by
Catharine June
EECS/ECE Communications Coordinator
cmsj@umich.edu or 734-936-2965
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