Visiting scholar lectures on national parks, databases

Students gained a new appreciation for the technology, time and effort that go into producing a map at Tuesday's Visiting Scholar Program presentation, "Mapping and Analysis of Vegetation in National Parks of the Southeastern [United States]."

Research scientist Marguerite Madden shared her field experiences with a packed auditorium of geology classes, personal wellness passport students and other students and faculty interested in environmental studies and technology in HHS Building, Room 3201. Her speech was sponsored by the Visiting Scholars Program under the College of Arts and Letters. It focused on "demonstrating the use of vegetation databases for park management activities, ecological studies and spatial distribution."

In her speech Madden described the process of applying complex analytical systems to the creation of vegetation maps, detailing the location, health and species of every plant within a park's land. Madden and her fellow researchers use two main environmental study "tools," GIS and global positioning systems, GPS, to compile and organize information into maps.

She defined GPS as "a system that uses a constellation of satellites and a receiver to triangulate positions on the ground." Madden explained a GPS is what people now can install in their cars to map their location and directions.

Mary Kimsey, associate professor of geography in the Center for Geographic Infomation Science, said her global issues class, GGEO 200, will be discussing environmental issues in the upcoming weeks.

"I thought it would be great for them to hear how environmental issues such as biodiversity of a national park are actually studied by an interdisciplinary team of scientists," Kimsey said.

According to Kimsey, "GIS is similar to a stack of maps of various types — land-use, water resources, road networks, et cetera — all in one computer database for a single location. For instance, Madden worked on the creation of a GIS for the Everglades and is now working on a GIS for the Great Smokey Mountains National Park."

Madden shared aerial photos and computer worksheets from her mapping projects in Florida and the Great Smokey Mountains National Park to illustrate step by step how a final map is produced.

First, aerial infrared photos are taken from large cameras built into the bottom of a plane. Next, photo-interpretation is hand-done on acetate on top of the photos, adding detail and correcting for data accuracy. The last step is editing and attributing the vegetation information onto the map with digital files.

"This is one the army of grad students do for hours on end," Madden said. The students identify individual trees on the photos and in the digital files to make ground control points. Audience members laughed when Madden enlarged photos onscreen to show how tiny and tedious a task it is to locate and match an individual treetop in the maze of thousands. "It takes a special person to do that," she said.

After the map is put together, aesthetic corrections are made for coloring and labels. "A lot of the editing that goes on after the map is finished is to make sure it is a usable map," Madden said.

According to Madden, the finished product looks very much like the detailed geography maps found in a science book, but the digital information embedded in it is much more complex than the what is shown on the surface.

Sophomore Nicole Bourret said, "It was interesting to hear how the GIS system works and all the hard work that goes into making one simple map that we take for granted, the people behind it and how many steps it takes."

The color infrared aerial photographs Madden uses can be used to determine whether a particular plant community is healthy or sick. For example, green trees are red on the infrared photo, and a red shade indicates a plant is healthy, but a light pink shade indicates sickness.

Madden explained another use of the vegetation maps is to determine different zones for forest fire management.

She said although some fires are natural or "prescribed," which means started purposely for a forest's health, "Unfortunately, most of the fires set are set by people in a park." A vegetation map can provide park rangers and fire personnel with fuel models to predict how hot, how fast and in what direction a fire might burn.

Madden's speech gave students an insight into how geographical studies have developed with technology and are being used today.

"I thought it was pretty informative," freshman Aaron Smith said. "Our whole class (Geology 200) deals with global issues but up till now it's been international issues, so it was good to focus on stuff that pertains to our country and not overseas."

Madden currently serves as associate director for environmental studies for the Center for Remote Sensing and Mapping Science at the University of Georgia, where she has worked since 1985. She is responsible for research in landuse, wetlands and coastal habitats and forest vegetation mapping using satellite image data, aerial photographs and geographic information systems techniques, referred to simply as GIS.

Madden is also a member of the editorial board of the International Society for Photogrammetry and Remote Sensing Journal.