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PROBLEMS OF GEOMORPHOLOGICAL MAPPING Geographical Studies No. 46, Warszawa 1963

H. Th. VERSTAPPEN Delft

THE APPLICATION OF AERIAL PHOTOGRAPH INTERPRETATION

IN GEOMORPHOLOGICAL RESEARCH

Summary: Geomorphology has a central position in aerial photograph interpreta-tion, because the landforms are the most conspicious phenomena in the 3-D image obtained by stereoscopic vision of aerial photographs. The differences between ‘static’ and ‘dynamie’ photo-geomorphology are discussed in relation to their ap-plicability. The importance of geomorphology for geological and pedological aerial photograph interpretation is mentioned, but special stress is laid on the role of photo-geomorphology in integrated surveys of natural resources and in studies of

water resources.

The rapid development of aerial photograph interpretation in the last two or three decennia has contributed substantially to the furthering of geomorphological knowledge. The perfection of the techniąues con-cerned has improved the quality of the aerial photographs to such an extent that stereoscopic study of them enables the expert to see, map and measure a wealth of geomorphological detail with an unprecedented speed and accuracy. At the same time a perfect insight is gained in the generał characteristics of the landforms occurring. No other means of observation gives the geomorphologist such a elear picture of the subject of his study! It is beyond doubt that aerial survey gave as important an impetus to geomorphology as the introduction of laboratory research methods in this field of science. Geomorphological aerial photograph interpretation is a very direct interpretation, because the terrain forms are by far the most conspicious phenomena in the three-dimensional image obtained by stereoscopic study of airphotos. There is comparatively little deduction involved and thus a high reliability is obtained. It goes without saying that a trustworthy interpretation can only be carried out by an expert in the field concerned and should be done in conjunction with field work. The advantage of the application of aerial photograph interpretation in the compilation of detailed geomorphological maps, f.i. to scalę 1 : 25,000—1 : 50,000, is obvious. It ensures an accurate, detailed and quick representation of the relief forms and the investigations can be carried out even if no accurate topographical map is available. The latter aspect is, of course, especially important in rapidly developing countries.

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