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SYMPOSIUM PHOTO INTERPRETATION, DELFT 1962 
becoming important. As an example of this recent trend, Polish geomorph- 
ological maps on a scale of 1 : 50,000 can be mentioned, and also “Natur 
räumliche Gliederung Deutschlands” (1953). D. L. Linton (1951) stated that 
“site” is the smallest unit of landform, and can be grouped in broader units 
such as “stow” and “tract”. 
The author also proposed a system of geomorphological regions using land- 
form type as the smallest unit of landform classification; stepping up to series, 
association, section and province (1950, 1956, 1961). The points to be discussed 
in such a systematization of geomorphological regions will be as follows: 
a. How to identify landform types and how to systematize them into larger 
units. 
b. To clarify the relation between landform types and regional units of soils 
and geology. 
c. To clarify the significance of geomorphological regions in the geographical 
sciences. 
In this paper the author will discuss items a. and b. 
Identification of landform type 
The land surface consists of various landform types which will be identified 
by morphological development and genetic features. In order to understand 
the geomorphological structure, it will be necessary primarily to identify each 
landform unit. The author has named such a unit of landform a “Landform 
Type”. Identical landform types should have the following four characteristics: 
a. development in about the same period of time; b. morphological similarity; 
c. a similar genesis, and d. similar constituent material. 
It is not so easy to identify landform types using these four criteria. For 
tunately, however, geomorphologists realize that these four criteria bear a 
close relationship to each other and it is possible to use morphological char 
acteristics as primary criteria. In order to identify landform types, not only 
the morphological characteristics, but also the boundary of the landform type 
as identified by morphological characteristics should be considered. If it is 
possible to recognize the boundaries, it will also be possible to introduce the 
techniques of the analysis of landform types from aerial photographs. 
Analysis of landform type from aerial photographs should be carried out by 
experts who have at least an elementary knowledge of geomorphology and 
photogrammetry and who have good stereoscopic perception. In general it is 
recommended to use aerial photographs on a scale of about 1 : 25,000. If 
available, aerial photographs taken in different seasons should be used. A field 
check should be carried out after the analysis of aerial photographs has been 
completed. Each landform type analysed on aerial photographs will be marked 
on transparent materials or transferred to topographic maps. The use of col 
oured symbols and signs for marking is recommended. 
The most important criteria for classifying landform types are micro-relief 
and morphologically discordant lines, which should be delineated on aerial