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SYMPOSIUM PHOTO INTERPRETATION, DELFT 1962 
b. Aerial photographs are a very important tool in the analysis of landform 
types. 
c. Analysis of landform types is useful not only for geomorphology, but also 
for other sciences and techniques related to landforms. 
Discussion 
Mr. G. W. Mitchell (U.K.) asked what is the distinction between landform, geological and 
soil units envisaged? Can these landform units be correlated with recognized geological and 
soil units, and have they been thus correlated in Japan? Dr. Nakano answered that landforms 
are not geological units or soil units, but that the land surface must be divided into several 
units by the four landform characteristics mentioned in his paper. In particular, if air photos 
are used for a geological or soil survey, the landform will be the primary criterion. He has been 
trying to discover the relationship between landforms and both geological and soil units. He 
has not yet succeeded, but it is becoming clear that close relationships do exist. 
Dr. P. H. T. Beckett (U.K.) remarked that the use of morphological units in soil mapping 
depends upon the assumption that a given combination of causes leads to a given landform and, 
by implication, a given combination of soils. But in some areas minor physiographic processes 
are dominant. These minor disturbances may determine the form of the soil pattern and the 
relation between recognizable landforms and soils may not be close. Did Dr. Nakano study 
the closeness of the relationship between soils and landform? Dr. Nakano answered that the 
relationship between soil unit and landform unit should be discussed in combination with the 
mapping scale. Soil units have an areal extension. This means that we can find some rela 
tionship between these units and the landform. 
Prof. Dr. C. Troll (Germany) remarked that the problem depends on the small natural units, 
both with respect to their descriptive differentiation and to the morphographic units or com 
plexes. Soil complexes are correlated to morphographic complexes, but also to other pheno 
mena. This leads to what has been called “Landscape Ecology”. For this purpose he defined 
the term “ecotope” which has a meaning similar to “facet” and “site” mentioned by Mr. 
Webster. There are now seven different terms, all trying to define the basic unit in the 
natural landscape. 
Prof. N. W. Radforth (Canada) asked whether the peat bog is a landform type according to 
the speaker’s use of the term? Dr. Nakano answered that according to him a peat bog is not 
a landform type. The area in which peat bogs occur can be classified into several units ac 
cording to his landform criteria.