Cornell's IRIS photo collection keeps an aerial eye on land-use changes

An aerial photograph from Cornell's Institute for Resource Information Systems shows the Cornell campus area in 1938. (Beebe Lake can be seen at the upper center of the photo.) Nicola Kountoupes/University Photography

By Roger Segelken

Imagine the dismay when scores of Suffolk County residents learned that their Long Island homes were built next door to -- and, in many cases, on top of -- abandoned waste-disposal sites.

Fortunately, old aerial photographs of Long Island had been preserved in Cornell's Institute for Resource Information Systems (IRIS). Sets of photos from 1947, 1962 and 1972 were used in a countywide evaluation to recall the murky underpinnings of modern suburbia -- a land-use history of mining operations that subsequently became waste dumps, pits and lagoons before developers and landscapers arrived to pave over a toxic legacy.

The Suffolk County Department of Health survey, which identified more than 1,000 "sites of concern" before focusing on 200 properties for detailed investigation, is one example of the power of archived aerial photographs. Now, to make sure IRIS's photographic prints don't "get buried," countywide collections are being digitized and Web-archived so that computer users anywhere can learn what the old neighborhoods used to look like.

"We have good coverage of every county in the state, but we're starting right here with Tompkins County. We will scan and convert several collections dating from 1936 up to 1991 to electronic media and make them available on Web servers," explained Eugenia "Jeannie" Barnaba, IRIS program leader in resource inventory. She credits a small grant from the Cornell Library system for jump-starting the digital archive project, but notes that additional funding is needed to preserve thousands more of IRIS's most important images.

"Every time we pull photographs for users, it puts wear and tear on the collection and takes away staff time from assigned projects. Digitization will preserve the data and potentially enhance access through the Web site by anyone -- students, faculty and staff, researchers in government and nongovernmental organizations, individuals, businesses and agriculture," according to Barnaba.

Before joining the Department of Crop and Soils Sciences, IRIS was part of the Cornell Center for the Environment, and the collection is still located on the third floor of Rice Hall. From 1984 to 1996, the program was known as CLEARS (for Cornell Laboratory for Environmental Applications of Remote Sensing) and before that, it was the Remote Sensing Program in the College of Engineering and the Resource Information Program in the College of Agriculture and Life Sciences. The director of IRIS is Stephen D. Degloria, who also is a professor and chair of soil and crop sciences.

Over the years, most IRIS special projects have involved land-use changes. Barnaba points to one, in particular, when IRIS's historical aerial photos helped geologists and soil scientists identify the most-responsible party for polluting a Superfund site in New York's Ulster County.

And now IRIS is moving from land to water with what Barnaba calls the most intriguing project yet, a multiyear survey of submerged aquatic vegetation (SAV) beds in a 100 mile stretch of the Hudson River. A first of its kind, the project brings together collaborators from Cornell, New York state's Department of Environmental Conservation and Hudson River National Estuarine Research Reserve, the Institute of Ecosystem Studies and New York Sea Grant.

Although boaters generally regard the so-called water weeds as a nuisance, Barnaba points out that many native SAV species offer environmental advantages, as habitat for sheltering animal life and by contributing oxygen to the water. One exception is Eurasian water chestnut, a non-native plant that grows in dense mats and depletes oxygen in the water column. By examining stereo aerial images with optical equipment, analysts can differentiate among the various SAV species and map plant beds of interest. As much as 15 percent of the Hudson between Kingston and Catskill is occupied by SAV, according to the study, which began in 1995. The results are expected to aid policy-makers in managing the Hudson ecosystem for years to come.

In an effort to collect annual data on some of the river's SAV beds, project managers enlisted local volunteers with two qualifications -- experience with kayaks or canoes and an enthusiasm for the Hudson. The citizen-science paddlers are trained with global positioning systems (GPS) to locate and document plant bed presence or absence, as well as bed density and condition.

"People really care about their local environments," Barnaba said,"and this collaboration provides the opportunity to collect useful information, in combination with strengthening environmental stewardship."

An IRIS index Total number of photographs: About 50,000 in 221 data sets, covering 57 New York counties and the New York City boroughs, between 1936 and 1995. Oldest imagery: 1936 Susquehanna Watershed collection. Biggest: Aerial photo enlargements mapping natural resources in New York City parks, printed to scale 1 inch = 200 feet, with some photos as large as 40-by-40 inches. Rarest: 1930s contact prints from silver nitrate plates that no longer exist. Newest: 2002 true color 1:14,400 scale photos of the upper Hudson River, made for the submerged aquatic vegetation study, but available to the public for any other purpose.