WORKING GROUP 3
NAKANO
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photographs. Delineated landform types should later be identified and named
by a synthesis of morphological characteristics.
Genesis and type of material will not necessarily have to be known for
identification, but one should be careful in definitely naming each landform
type. Genesis and materials of doubtful units should be particularly checked
during the field investigation.
As stated above, landform types will be grouped into landform series, asso
ciations, sections, provinces and divisions by reducing the criteria for ident
ifying the landform type. Such systematic grouping of morphological regions
will also be carried out on aerial photographs. For this purpose it is recom
mended that no magnification is used, because systematization should be done
by broad observation. Conversely, it is practical to set up morphological
regions from larger to smaller units.
Application of analysis of landform type
The Japanese Islands located on the Circum-Pacific Orogenic Zone have
been subjected to tremendous crustal movements up to the present day. In
other words, complicated features of landform reflect the geological and geo-
morphological history. Therefore, analysing the micro-geomorphological fea
tures, we can study many geological events. For example, geological structure
is deduced from characteristic landform features on aerial photographs. That
this is possible has been proved by photogeological studies.
Pedological analysis of aerial photographs by Dr. P. Buringh proved the
advantage of aerial photographic analysis of landform units. So far as we have
experienced in Japan, this method will also be very instructive for Japanese
soil scientists. In the soil survey of mountainous and hilly regions and diluvial
upland regions particularly, it was recognized as a technique to be recom
mended. It will also have to be applied to the soil survey of paddy fields.
Although the paddy fields of Japan have been deformed artificially, we can
trace the micro-geomorphological features of the alluvial plain on the aerial
photographs by stereoscopic observation.
Analysis of landform type has been applied to land classification for land
use improvement. In this case, analysis of landform type is the basis of land
classification survey, and the delineated landform types are translated to land
units by combining landform, geology and soils data.
The landform classification for flood prevention is also based on landform
classification by means of aerial photo interpretation. We have applied the
same ideas of landform classification to the population map on chorographic
scale and have compiled a population density map by landform division.
Conclusion
a. Analysis of landform types will be very useful for understanding the char
acteristic features of land surface.