Tracking historic photos took detective work January 11, 2009Posted by Bahadir Sahin in Calismalar (Studies), English, Haber (News).
Tags: aerial photos, Map Library, USDA Farm Service Agency
The DNR had to do its own detective work to track down the aerial photos, originally authorized in 1933. The forerunner of today’s USDA Farm Service Agency ordered the statewide aerial photography as a tool to review land uses, ensure compliance with acreage reduction programs and develop soil surveys.
It took four years to find and process these first statewide aerial photos. Originally housed in what are now the county offices of the Farm Service Agency, some of these photos had been lost. Most were found in the Iowa Department of Transportation’s archives where they were used to develop roads. The DNR and partners unearthed other photos in USDA offices and the University of Iowa’s Map Library. As a last resort, the DNR purchased some photos from the National Archive.
Advertisement Once found, the DNR and Iowa State University had to align the older photos with current ones, and then weave the photos together by county, before they could create the computerized version.
The project was funded by the U.S. Environmental Protection Agency and the Iowa DNR.
“Iowa was the first state to use brownfield money for this project,” said Mel Pins, brownfield coordinator. “We used a federal grant to find the aerial photos in highly populated areas where we were most likely to find some industrial sites that could potentially be contaminated. Then we expanded the project to cover the entire state.”
Brownfields are abandoned, idled or under-used industrial and commercial areas where real or perceived environmental contamination can complicate expansion or redevelopment.
The brownfields program has funded the project at about $40,000 to $50,000 per year, most of it spent on staff time to locate the photos, compare new and old photos and create the new photo images.
Project partners also have provided funding and technical support. They include Iowa State University’s Geographic Information Systems Facility, and the DNR’s Brownfields Recovery Program and GIS Section.
Pins, also an amateur historian, said it’s essential to preserve these first aerial photos as this kind of land use history is just not available from other sources.
“The best historical land use resource we previously had were the Sanborn Fire Insurance Maps, produced from the 1860s through the 1970s,” he said.
“But they only covered larger cities and no rural areas. And, local archives, including building permits, property abstracts, and city directories simply did not indicate the type of land use that might have natural resource impacts,” Pins said. “There’s nothing better than truly being able to look back in time at a real aerial photo of a site.”
As a next project, the DNR is actively acquiring aerial photos from the 1950s to preserve land use information. As funding becomes available, the partners will move forward in time, producing web-based, computerized, aerial photos from each decade in the latter half of the 20th century.
Information from the 1940s will not be available because statewide aerial photos were not taken in that decade due to World War II.