地形改変研究の動向-その展望

抄録

The intensity of landform transformation due to various kinds of large-scale land development in Japan has been magnified since the 1960's when Japanese postwar high economic growth came in real earnest. Japanese geographers, however, paid only a little attention to such phenomena except natural disasters caused through human impact on land. On the other hand, geographers in foreign countries, such as the United Kingdom, the United States, France, Germany and East European countries, have continuously recognized from early times the important role of man as a geomorphic agent and they have accumulated field studies on landform transformation in the process of systematic establishment of anthropogenic or environmental geomorphology.
In the last few years, the importance of landform transformation studies has gradually been recognized in Japan. In order to promote systematic and comprehensive studies, a Working Group on the Man-Made Landforms and Land Transformation was organized in 1980 in the Association of Japanese Geographers, and a symposium on “Land Transformation and Related Environmental Changes” was held in 1981. This special issue on “Landform Transformation” carries the papers which are rewritten from the reports presented in the symposium.
This paper aims at overviewing the trends and problems inherent in the previous and recent Japanese studies on anthropogenic transformation of landforms and landforming process through a comparative review of foreign studies and at promoting the progress in this field. In the English-speaking countries, landform transformation problems have been studied since Marsh (1864) and Sherlock (1922), who wrote “Man and nature” and “Man as a geological agent”, respectively. Among the problems, man-induced soil erosion has been recently highlighted over again to contribute to solve the environmental problems, which proved to be more urgent in the 1970's. In the French-speaking countries, accelerated landforming processes caused by human activities have been studied both in the homelands and the former overseas settlements through a climatic geomorphological approach. In Germany, the concept of anthropogenic geomorphology was introduced by Fels (1934) and the studies similar to those in the French-speaking countries have been performed mainly in Central Europe. In the East European countries, in particular in Czechoslovakia and Poland, classification and mapping systems of anthropogenic landforms have been intensively studied.
Japanese geographers tried to analyse both ancient and recent landform transformation and related environmental changes as a part of the subjects of historical and applied geography, respectively, though they paid little attention to the man-made landforming processes themselves which have been recognized through recent activities by the members of the Working Group on the Man-Made Landforms and Land Transformation.
However, many tasks require further research in the context of landform transformation studies and their application to environmental management. In particular, following subjects must be stressed hereafter.
1. Socio-economic analysis related with landform transformation and its control,
2. Morphogenetic classification and mapping system of man-made landforms,
3. Historical approach enabling the reconstruction of long-term man-induced geomorphic processes,
4. Comparative geographic studies including climatic geomorphological approach,
5. Experimental studies and field measurements of man-induced geomorphic processes,
6. Assessment of the magnitude, areal extent and temporal sequence of the resulting effects on environment, and
7. Comprehensive land transformation studies and their application to environmental managemeut.