Earth Science (Chikyu Kagaku)

Show abstractHide abstract

The study of morphological evolution or erosional history of mountainland forms the center problem of present geomorphology. Such a trend of geomorphology has been criticized by geographers. The points of critic are summarized as follows: 1. Plain geomorphology is one of the new subject of future geomorphology. 2. Previous geomorphology is too unrealistic, too geological and too unadequate coverage. 3. For the study of plain geomorphology, it is necessary to use aerial photos. For the geomorphological surveys we have used topographic maps. But aerial photos. are also very useful for this purpose. The usefulness of aerial photos is summarized as follows: 1. Accuracy is uniform. Various elements of landforms are represented stereoscopely and synthetically. 2. Field surveys are very economically and rapidly accomplished by using aerial photos. 3. Laboratory works are repeatedly tried on aerial photos. 4. Developmental process of landforms such as sand spits, offshore bars etc. are systematically studied by aerial photos taken in different conditions. The author describes some results of photogrammetric surveys of plain landforms. We classify the landsurface depended on various factors……landforms, soils, ground water conditions……and represent that results as geomorphological map. The author examines this problem in the area along the River Naka, Tokushima Pref., Itsukaichi Region, Tokyo Pref. and some locations of Chiba Pref. As one example of developmental process of landforms, the author. describes the development of offshore bars of the river mouth of the Naka, using the aerial photos taken in different seasons and tide conditions.

View full abstract

Download PDF (892K)

Register with J-STAGE for free!