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SYMPOSIUM PHOTO INTERPRETATION, DELFT 1962 
is another old element of human origin. A turf wall (11) surrounds an area in 
which can be traced some very faint, parallel lines (12), indicating old arable 
land, probably a Medieval field. 
Thus we find that every spot on the heath bears traces of human activity of 
some kind. But some of those traces are now important documents of earlier 
manners of living. It is our hope that the human activities of today on the 
Skanor peninsula will not spoil the last remnant of that old landscape type but 
make it into a valuable nature and culture memorial, by protecting it against 
further encroachments. 
Reference 
1. Rasmusson: The drainage of lake Bockabosjön, Svensk Geogr. Ârsbok 1961. 
Discussion 
Dr. Steiner (Switzerland) asked after how long an interval an area is re-photographed in 
Sweden. The speaker answered that Sweden is divided into 7 parts. Every year one of these 
is being re-photographed (scale 1 : 30,000). The intervals are therefore 7 years, but bad 
weather can upset the planning. Besides this sequential photography each year large areas 
are photographed at a larger scale for special purposes. This photography is fairly irregularly 
distributed over the country, without following any plan from year to year. The Swedish 
Air Force made 2-3 small scale coverages (1 : 66,000) of nearly the whole country from 1957 
onwards. 
Dr. Schneider (B.R.D.) suggested that old aerial photographs taken for photogrammetric 
purposes, be filed as documentation material of the landscape at a particular moment. 
Gen. R. LI. Brown (U.K.) asked in connection with this what institutions exist in the several 
countries for air photo documentation? Dr. Rasmusson answered that all air photos taken by 
the Swedish Geographical Survey (Rikets allmanna kartverk, Stockholm) since 1934, are kept 
in archives in the form of negatives plus one set of prints. They are arranged chorologically 
according to our 24 counties, and within each county they are also sorted chronologically. 
The location of each picture is plotted on topographic maps on scale 1 : 100,000. At the 
Dept, of Geography at Lund University we have started to build up a “phototek”, consisting 
of vertical and oblique air photographs as well as terrestrial ones. Our main object is to take 
care of old material outside that of Rikets allmanna kartverk, as we feel that it has great 
documentation value. 
Mr. Skappel (Norway) asked if the speaker had made any use of the Swedish cadastral 
photo-map in his geographical work. Dr. Rasmusson answered: The economic photo-map 
1 : 10,000 of course is a very valuable base-map, for example when plotting details from air 
photographs onto a map with the aid of a sketch-master. But unfortunately this economic 
map doet not yet cover Scania, so it could not be used in the study presented here. Further 
more it is almost impossible to make a real photo interpretation on it because a green tone 
has been printed over all non-arable land. 
Dr. Hottes (B.R.D.) advocated that the release of aerial photographs for interpretation 
purposes be facilitated. Older photos with industrial objects, normally classified, should be 
reconsidered. The paper shows that in Sweden this is possible. The speaker remarked in this 
connection that for about 2 years it has become much easier to obtain aerial photographs in 
Sweden. Only more important military objects remain covered up on the prints. A drawback 
remains the high price (about D.M. 20.— for a contact print.).