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SYMPOSIUM PHOTO INTERPRETATION, DELFT 1962 
At that time, aerial photographs were mostly used for photogrammetric 
mapping related to forestry, urban planning, dam construction, land reclama 
tion and other projects, but not for photogeographic work. This was because 
until the end of the war we had no experience of photogeography and no 
organization responsible for it. Photogeographic studies have made only slow 
progress among the geographers in the Geographical Survey Institute. 
The fundamental research survey of land, and the comprehensive develop 
ment of river basins were urgently needed, not only because of the shortage of 
various resources due to the war damage, but also because of damage due to 
the severe flood disasters in 1946, ’47 and ’48. Under such social circumstances, 
laws were passed for land research, including a cadastral survey and a land 
classification survey and for comprehensive land development. 
As a result of the law for comprehensive land development, a land use sur 
vey, using aerial photographs, began in 1952 after a two year trial survey. The 
land use survey has been carried out mainly for the special areas subjected 
to the comprehensive development plan, under the administrative and tech 
nical supervision of the Economic Planning Agency and the Geographical 
Survey Institute (Ministry of Construction), using the fiscal budget granted 
by the national and prefectural governments. Up to the end of March 1962, 
336 sheets of land use map on a scale of 1 : 50,000 had been printed in 11 
colours. The same technique has been applied to Hokkaido, the most prom 
ising district for comprehensive development in Japan, and the land use map 
on the scale of 1 : 200,000 will be completed within some years. 
The land classification survey, regulated by the law for land research, has 
been carried out since 1951 to give the fundamental data for better land use 
and land conservation under the supervision of the Economic Planning 
Agency. In cooperation with geomorphologists, geologists and soil scientists, 
technical regulations or manuals for land form classification survey, surface 
lithology survey and soil survey were established in 1953. The Geographical 
Survey Institute is responsible for the landform classification survey and 13 
sets of landform classification maps, drainage and valley density maps and 
slope gradient maps with explanatory text have been published as the pilot 
sheets. The principle of landform classification is the analysis of microgeo- 
morphological features on the aerial photographs. The same principle was 
applied to the study of flood prevention by the members of the Science and 
Technique Agency. The usefulness of this for flood prevention survey was 
proved on the occasion of the Isewan Typhoon in September 1959. For this 
reason, landform classification survey for flood prevention has been carried 
out by the Geographical Survey Institute for the regions subject to inunda 
tion due to river floods and high tide. The results of this survey have been 
published as a set of maps and explanatory text for Tokyo District. 
The making of photomaps began in 1961. As the base map for regional 
planning, the Geographical Survey Institute compiled photomaps on the scale 
of 1 : 25,000 with overlays showing land use, land type, place names and 
other necessary information. This year the same techniques will be applied