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5 decades of Iowa aerial photography available on DNR website

Ag/Outdoor, News

October 20th, 2014 by Ric Hanson

Iowans have a way to look into Iowa’s past and view changes of their entire state, from decade to decade, thanks in part to REAP funding of the Iowa Historic Digital Aerial Photo Project. The public can now see where former buildings were located, what kinds of industries and operations were on a site 70 years ago, and how development and urbanization has changed Iowa’s city and agricultural landscapes by visiting http://programs.iowadnr.gov/maps/aerials/.

In 2009 and 2011, Historical Resource Development Program grants from REAP helped the DNR’s Geographic Information System Section procure photographs from various archives across the state and nation. Archives in Washington D.C., the University of Iowa Map Library, the Iowa Department of Transportation, the U.S. Department of Agriculture’s Aerial Photography Field Office, county offices and private national archives all contained valuable pieces to Iowa’s geographic time puzzle.

Steve King, deputy state historic preservation officer, said “The Iowa Historic Digital Aerial Photo Project makes these images available to researchers, developers, landowners and others who need to understand the history of properties in Iowa. We appreciate preserving these important historical documents and making them available online to Iowans and others around the world.”

Developers, landowners and managers, and planners often need to understand how a property was previously used in order to evaluate history’s environmental and character impacts. Knowledge about a site’s resource use is also beneficial, and difficult to find elsewhere. Soil and streambank erosion patterns, conservation improvements and changes in natural vegetation and habitat can also be used to compare trends in land use and natural resource management.

Once the photos were scanned and made digital, GIS staff diligently matched them to their actual location. A processing algorithm then aligned the photos into blocks, which were mosaicked together to produce statewide coverage. Because of this approach, the photos can now be viewed with other mapped features such as roads and land boundaries.

The GIS Historic Aerial Photography Project took more than eight years to complete, from 2004-2012, because of its detail specific and comprehensive nature.