increased during the 1968-1972 period. Professionals 
from several institutions have joined, which promoted 
professional development. In 1970, a Hungarian delegation 
of 20 attended the Symposium of the 7th Committee af 
ISP, presented 1^5 papers, and participated in the work of 
the international subcommittees. 
Our working committee co-ordinates the activity of a 
number of special fields, and promotes the development 
of the methods employed. Results of this work can be 
summarized as follows. 
Photogeology is the professional field, above all, of 
the different departments of the Hungarian National Geo- 
logical Institute. Significant results could be achieved 
by aerial photo interpretation in the 1:100000 geological 
mapping of the Great Hungarian Plain by the discovery of 
buried furrows and covered river bed courses, and by 
detecting the boundaries between sand and clay areas. In 
the highland of Northern Hungary, aerial photo interpre- 
tation was used in 1:25000 geological mapping as the 
stereo-photos could detect the frontiers of sedimentary 
and volcanic rocks, lava and cinder banks, their gra- 
dient, as well as the buried furrows and andesite seams. 
Similarly aerial photographs were used for the 1210000 
mapping and engineering geological survey of the Balaton 
lake highland, and for the 1:25000 mapping of the 
Tra ‚nedanubian Range. 
A continuously en number of Hungarian professio- 
nals are participating in the geological mapping and raw 
material prospecting activities of the developing 
countries, just; like in the development of their aerial 
survey techniques, including Mongolia, Mali, Mauritania 
Guinea, Chile, Peru, Algeria, Tanzania, Turkey, Cuba, 
etc, 
Geomorphologic aerial photo interpretation is associated, 
above all, with the 1:10000 and 1:25000 geomorphological 
maps, but can be made similarly good use of in the 
research work on certain geomorphological problems. 
Geomorphological research and mapping are carried on by 
the Geographical Research Institute of the Hungarian 
Academy of Sciences. These techniques were successfully 
employed so far in valley and slope studies, investiga- 
tions on river course erosion phenomena such as terraces 
and runways, examinations of quicksand forms and 
2442/87