Use the "back" button of your browser to return to the list of abstracts.
RECOVERY AND USE OF AERIAL PHOTOGRAPHS OF ETHIOPIA IN 1935-1941 [Abstract ID: 0514-04]
The Italian aerial photographs produced by the Istituto Geografico Militare (IGM) in 1935 to 1941 have been discovered, scanned and organised, in the framework of a cooperation agreement between Ghent University, the Ethiopian Mapping Agency, and Mekelle University. Until recently, the earliest aerial photographs of the country that were available had been taken in the period 1958-1964. The set of aerial photographs made in 1935-1941 consists of 8281 assemblages on approx. 50 cm x 20 cm hardboard tiles. Each of these tiles holds a label, one nadir-pointing photograph flanked by two low-oblique photographs and one high-oblique photograph. The four aerial photographs were exposed simultaneously and were taken across the flight line. The high-oblique photograph is presented alternatively at left and at right. In many cases, there is approx. 60% overlap between subsequent sets of aerial photographs. One of Santoni’s glass plate multi-cameras was used, with focal length of 178 mm and with a flight height of 4000-4500 m a.s.l., which resulted in an approximate scale of 1:11,500 for the central photograph and 1:16,000 to 1:18,000 for the low-oblique aerial photographs. The surveyors oriented themselves with maps of Ethiopia at 1:400,000 scale, compiled in 1934 by IGM using all older partial maps available, as well as field surveys by spies. The flights present a dense aerial photo coverage of the Tigray highlands (approx. 30% of the area is covered), where they were acquired in the context of upcoming battles with the Ethiopian army. Several flights preceded the later advance of the Italian army southwards to the capital Addis Ababa. Further flights took place in central Ethiopia for civilian purposes. As of 1936, the aerial photographs were used to prepare topographic maps at 1:100,000 and 1:50,000 scales. To re-process the imagery, procedures using digital image-based modelling have been developed. The 1935-1941 aerial photographs, together with those of 1958-1964, 1986-1994 and recent high-resolution satellite imagery, are currently used in spatio-temporal analyses, including change studies of land use and cover, hydrology, church forests, land management and geomorphology in Ethiopia over a time span of 80 years. There is scope for a wide array of additional research concerning for instance historical geography, military geography, urbanisation, or early long-distance tracks.