In Japan, the movement from rural prefectures to metropolitan prefectures has been a major migration stream since the middle of Meiji Era when the industrial revolution started. This long-standing trend, however, has changed recently. The prominent stream is the migration from metropolitan prefectures to rural prefectures which is reverse of the long-standing trend.
This stream is called “U-turn” which means return migration. We have a lot of discussions about it. This subject may be investigated in the broader context. The author aims at detecting the epoch of internal migration in postwar Japan and the major factors which affect the recent internal migration including “U-turn” phenomenon.
This study, first, examined the change of the net migration rates for prefectures shown in “Annual Report on the Internal Migration in Japan Derived from the Basic Resident Registers” (Table 1). By the application of T-test method which discerns statistically the significant difference between two mean values, it is detected between the former and the latter halves of the 1960's. Namely, it was not until the latter half of the 1960's that the internal migration in Japan has shifted to a new stage. Out-migration from rural prefectures became weaker, so that population concentration towards metropolitan prefectures was less distinct than before.
Secondly, major factors that affect the inter-prefectural migration were examined by multiple regression analysis. The years of 1955 and 1970 were chosen for the analysis, before and after the epoch, and all the 46 prefectures were grouped into two categories, i.e. metropolitan (10 prefectures) and non-metropolitan (36 prefectures). The former consisted of Keihin (Saitama, Chiba, Tokyo and Kanagawa), Chukyo (Gifu, Aichi and Mie) and Keihanshin (Kyoto, Osaka and Hyogo).
The inter-prefectural migration movements were summed up in the following four types;
type A. inter-prefectural migration in total
B. migration from non-metropolitan prefectures to metropolitan prefectures
C. migration from metropolitan prefectures to non-metropolitan prefectures
D. inter-metropolitan migration
From Tables 3 and 4, following findings have been obtained.
1) For 1970, the coefficients of determination for all four migration types show decline. Therefore, recent migration is affected by more complex and numerous factors.
2) Inter-metropolitan migration (Type D) is affected by more limited factors than types B and C, namely migration between metropolitan and non-metropolitan areas.
3) The factor of inter-prefectural difference of per capita income is less valid for explaining all of the four types mentioned above, however, employment increase in destination still plays an important role. So-called “decline of economic motivation” might be partly approved.
4) Distance is a strong and stable factor. Figures 1_??_4 show that migration is considerably determined by contiguity.
5) The factor of accumulation of the higher central functions in major cities of prefectures in destination, which is considered as a leading factor for city growth, does't always play a significant role in all of the four types of migration.
6) Other important factors are the psychological attitude towards migration behavior indicated by both a sum of past migrants for destination and a propensity not to migrate. The migrant's attributes represented by age and education are also important.
Furthermore, multicollinearity, that is one of several troublesome problems in application of multiple regression analysis, is examined by Riddell's method. However, it is clear that this problem does not distort original regression model used in the analysis as seen from the Table 4.

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The expansion of the new transportation networks, including supper-express railroads, expressways, and the reconstruction of highways, have great influence on the competitive relations between cities. Particularly, local cities are facing urban remodeling and improved services for their hinterlands by constructing these networks.
The purpose of this symposium was to make clear through studying the impact which results from the new networks, the changes in urban functions and urban spheres.
The reporters were as follows:
1. FUTAGAMI, Hiromu and JITSU, Kiyotaka: Changes in urban functions along Hokuriku Expressway.
2. KITAGAWA, Kenji: Changes in urban functions along Chugoku Expressway.
3. YOKOYAMA, Shoichi and KAGAWA, Katsutoshi: Competitive relations between cities—a case of the Western Shikoku.
4. DOI, Shigehiko: Changes in transportation networks and urban system in Shikoku.
5. KONNO, Shuhei: Changes in marine transportation and port city.
Through considering the reports, comments, and discussions, the organizers recognized that this symposium achieved quite good results. The following point, however, remains to be studeid: positive approach to analysis of the mechanism of influence by the new networks.

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Since the 1960's rural areas in Japan have been rapidly transformed through the influence of urbanization and industrialization, which provided the increased opportunity of employment in cities. Migration of people from rural areas to urban areas as labor force has necessiated mechanization of agriculture, which in turn has accelerated depopulation of the rural areas. In extreme cases, it has become difficult to maintain community system of the settlement, particularly due to out-migration of the young.
The purpose of this symposium was to examine the relationship between such changes in settlements and the processes of reorganization of areas.
The reporters and their themes were as follows; (1) H. Okahashi: Changes in the mountain rural areas in northeastern Aichi Prefecture caused by the starting of factory-commuting. (2) A. Nagaoka: The effects of industrial complex development on the rural area in southern Yamagata Prefecture. (3) T. Gomi: The influence of changes in traditional irrigation systems on a rural community in central Nagano Prefecture. (4) Y. Tomatsuri: Beef cattle raising and its preventive effects on the depopulation in mountain villages in eastern Tottori Prefecture. (5) T. Miyaguchi: Changes in economic structure of mountain settlements in southern Kumamoto Prefecture caused by development of the large-scale forestry. (6) Y. Fujita: The effects of reorganization of the community-owned forests in southwestern Fukushima Prefecture. (7) T. Tanaka: The recent changes in fishing villages along the Japan Sea.
Many questions and opinions were presented on the floor mainly concerning: 1) what factors caused changes in rural areas; 2) processes of the reorganization; 3) what kind of role did community play on the changes in settlements; and 4) who promoted enlargement or curtailment of businesses in agriculture and forestry.

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This symposium was designed to review the present tephrochronological studies in Japan and to discuss the problems of future research.
The papers presented by reporters and commentators are as follows. (1) Relationships between development of volcanoes and tephras, by Ichio MORIYA, (2) Tephrochronological study of Mt. Ontake volcano, by Takehiko KOBAYASHI, (3) Identification of tephra, by Fusao ARAI, (4) Tephrochronology of deep-sea sediments, by Toshio FURUTA and Kazuo KOBAYASHI, (5) Correlation and chronology of coastal terraces and associated sediments around Tokyo Bay in middle Pleistocene analyzed by marker-tephras, by Shigeo SUGIHARA, Fusao ARAI and Hiroshi MACHIDA, (6) The 1977 tephra of Mt. Usu volcano, by Yoshio KATSUI, (7) Some problems of tephras in Shikoku region, by Yoshio YASUDA and Hiromi MITSUSHIO, (8) Slope development with reference to tephrochronology, by Toshikazu TAMURA and Michio NOGAMI, (9) Some properties of soils of tephra origin, by Naganori YOSHINAGA, (10) Quaternary air circulation analyzed by distribution of tephra, by Masatoshi YOSHINO, (11) “Akahoya ash” in Southern Kyushu identified by determination of minor elements in ferromagnetite from tephra, by Yoshitaka NAGATOMO, (12) Forming processes of tephric soils with reference to tephrochronology, by Shigeo ASAMI.
Discussions
(1) Tephrochronology would be most useful for establishing eruptive history of a volcano. (2) Substantial descriptions based on petrographic and chemical determinations of most tephras in Japan are being carried out and could contribute to the finding of the wide-spread and the most important time-marker tephras. (3) Tephrochronology of deep-sea sediments will no doubt contribute to the developments of Quaternary studies on worldwide climatic history as well as on volcanism. (4) A detailed tephrochronology would provide a basis for revising and constructing geomorphological development and stratigraphy over extensive areas. (5) Drifted tephras by currents will be meaningful for correlating marine sediments and estimating palaeo oceanic currents. (6) Quaternary wind systems will be more precisely restored by distribution of tephra formations and/or groups over various ages. (7) Slope processes and its developments should be more fully analyzed by observations of tephra mantling. (8) Soil forming processes and the rates would be successfully clarified from the standpoint of tephrochronology.

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