Old aerial photos reveal concealed waste dumps 

A great part of Denmark’s 300,000 marlpits are well filled with chemicals, building waste and bulk waste. Throughout the 1960s and 1970s, industrial companies as well as private individuals in Denmark were liberally dumping rubbish into holes in the ground and covering it with earth. This today makes it very difficult for local and regional authorities to identify old marlpits and waste dumps that may constitute an environmental hazard.

But COWI is currently involved in a project to digitise more than 40,000 historical photos and make them accessible, and in so doing give an overview of Denmark prior to the boom in urbanisation and industrialisation. The photos date from May 1954, when during a three-week period the UK’s Royal Air Force photographed the length and breadth of Denmark.

Valuable photos

By comparing these photos with COWI’s digital images - Denmark’s Digital Orthophotos (DDO) - which are updated every two years, changes in the landscape can be observed in detail. This provides a good basis for identifying old waste dumps, companies, polluted ground and archaeological excavations.

The photos are also ideal for documenting ways of restoring wetlands and gaining an overview of the way in which farmlands have changed in relation to the landscape. The photos will prove invaluable to planners, historians, cultural geographers, archaeologists, the judicial system, lawyers, countryside preservationists and environmentalists.

Good quality

COWI’s senior project manager Steen Davidsen says: "To ascertain the suitability of material which is after all 50 years old, we ran a pilot project which involved scanning 100 of these aerial photos taken over the town of Odense, and we were very surprised at how good the quality of the photos is.

This quality, of course, reflects the fact that the Royal Air Force used the very best equipment available in those days and that they photographed from a height of about 1,500 metres. As a result, the old aerial photos are almost as detailed as modern-day photos, which are taken from a height of three kilometres."

Stored on celluloid film

Steen Davidsen adds: "In all probability, these old aerial photos were part of a NATO project carried out against the background of the Cold war. But actual information about why they were taken is not publicly available at the present time."

Since 1954 the material has been stored on about 300 rolls of celluloid film in the possession of Denmark’s Tactical Air Command, based in Karup, but some years ago it was declassified and made available to the public in analogue form under the name Basic Cover 54. Because the photos are more than 30 years old, they are no longer under copyright protection. However, digitising them all is costly.

Therefore COWI is currently letting potentially interested parties, including DDO customers, know about the opportunities afforded by digitising and georeferencing, or geocoding, this extensive library of photo material.

By: Christina Tækker, cht@cowi.com
Published: 25.05.2004