At clear, calm nights, the strongly stable layer called cold air lake is formed in the bottom of the basin and at the lower part of the slope. In order to make clear the processes of the formation of cold air lake and the relation between cold air lake and local circulations including cold air drainage, observations were carried out in the Sugadaira basin and on the slope of Mt. Ohmatsu in Nagano Prefecture, Japan, from May 6 to 10, 1982. During the observation period, the self-recording bimetal thermometers were set at 8 points in the study area. Wind directions and velocities were recorded at 2 points in the same area. Simultaneously, the vertical wind and air temperature distributions were observed by means of the tethered balloons up to 200m height above the ground (Fig. 1).
The results of the observations are summarized as follows:
1. At night, three sub-layers were distinguished above the bottom of the basin. The lowest sub-layer is thermally stable, in which wind direction is along short axis of the basin and its velocity is less than 0.0-0.5m/s. The middle sub-layer is also stable and the winds formed on the surrounding slopes blow into it, when the daily minimum temperature occurs in the basin. The third sub-layer is almost neutral and the general wind prevails. In this paper, the lower and middle sub-layers are defined as cold air lake (Fig. 5).
2. After sunset, wind becomes weaker than in the daytime and its direction becomes along the short axis of the basin in the air layer near the ground in the bottom of the basin and at the lower part of the slope. The air drainagee occurs at the upper part of the slope. Under these conditions, the cold air lake is formed in the basin within two hours after sunset (Figs. 2, 3, 4, 5 and 6).
3. The cold air lake has its own wind systems and circulations. The general wind has an effect on the height of the cold air lake but little effect on the inside of it. So the time variation of the air temperature (potential temperature) in the upper sub-layer is almost constant, but in the inside of the cold air lake, it decreases by 7_??_10°C (Fig. 5) . 4. In the period when the general, synoptic-scale wind is weak in the upper sub-layer, the thickness of the cold air lake reaches up to 80_??_90m. This height is about 1/2 of the ridges surrounding the basin (Fig. 5).
5. When the daily minimum temperature occurs, the difference of the air temperature (potential temperature) between the top of the cold air lake and the bottom of the basin becomes 7_??_12°C (Fig. 5).
6. When the general, synoptic-scale wind becomes strong occasionally, the thickness of the cold air lake becomes low down to 20_??_30 m and air temperature rises on the: slope. This regime is named “break” in most cases, which continues 2_??_3 hours and commonly observed at clear, calm nights. During the break, air temperature continues to decrease in the cold air lake (Fig. 5).
7. When cold air drainage flows down on the slope, air temperature decreases only by 3_??_4°C. So the difference of air temperature between the slope and the bottom of the basin reaches almost 5_??_7°C (Figs. 4 and 6).
8. When cold air drainage flows down on the slope, the fluctuations of wind velocity appear as surges with periods ranging 40_??_50 minutes and about 20 minutes, and air temperature 50_??_60 minutes, 30_??_40 minutes and about 20 minutes (Fig. 7).

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In Japan, the fishery labor market is rather “closed” in following three meanings. First, the mobility of laborers between the fishery and other industries is very small. Second, the mobility between the different fishing types is also small. Third, those mobilities are regionally limited.
Recently, these “closed” nature have changed to “open” because of modernization of employment and working systems of fishery. The author thinks, therefore, it is one of the important geographical problems to analyze the various regional aspects of the changing labor market.
1. From the viewpoint of composition of fishermen on each fishing boat, regional aspects of fishery labor markets are classified into two types, regionally “segregated” type and regionally “integrated” one. The segregated type means the state in which the native places of the crew of every fishing boat are regionally restricted. While, in the integrated state, they are regionally integrated, and crew members are from different regions. We can regard the former state as a regionally “closed” labor market, and the latter state as an “open” one. In the process of modernization of fishery labor market, its regional aspect is hypothesized to change from the closed state to the open one. This change means the collapse of regional or territorial “separatism” of fishery labor market.
2. In practice, it is difficult to distinguish segregated type from integrated one unless there are some quantitative measures. Therefore, Segregation Index is applied in this study. This index is a useful tool to measure the degree of residential segregation of social groups in a city. If we regard a “fishery labor market” as a “city” and “territorial groups of fishing laborers” as “social groups, ” then the application turns to be feasible.
The method mentioned above was applied to eleven labor markets which contain four different fishing types (squid fishing, salmon drift net, tuna long line and deep sea trawl) at five fishing ports (Hachinohe, Kamaishi, Kesen'numa, Ishinomaki and Shiogama) in San. riku Coast in north-east Japan.
3. The obtained indexes are more similar in a fishing type than in a fishing port. That is, the most high valuee is found in squid fishing (0.76), somewhat lower values are found in salmon fishery (about 0.66_??_0.73), and very low values are found in deep sea trawl (about 0.46_??_0. 61) and tuna fishery (about 0.44_??_0.53). Each value represents the state of modernization in working and employment systems of each fishing type.

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This symposium was organized to discuss the rapid transfiguration of the Seto Inland Sea Area for the last 25 years from six viewpoints; transportation revolution, urbanization, indusrti-alization, water resources, agricultural change and development of islands. Presented papers are as follows.
1. Yokoyama, S.: Effect of the development of new transportation system
2. Kitagawa, K.: Change of urban functions of the cities in this area
3. Murakami, M.: Industrial development of the area-change from new industrial citites and special industrialization region to technopolis-
4. Moritaki, K.: Water resource problems
5. Yokota, T.: Transfiguration of agriculture and rural villages-using tobacco farming as an indicator-
6. Uchiyama, Y.: Transfiguration of the mikan (Japanese orange) producing region- case of In'no Shima City-
7. Asano, H.: Effects and future problems of the development Aact of Isolated Islands
Two comments were given to each paper by commentators.
This symposium was characterized by many comments from many specialists in various fields concerned with regional development ; seven geographers, two economists, two local administrators and one agricultural scientist. Therefore, each opinion was diversified, suggestive and stimulating. Our purpose was to review the human geographical studies on the Seto Inland Sea Area and to prepare for the further study on the change of this area. We are convinced that these aims were attained.

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This symposium was organised as a first attempt to hold a discussion among Japanese geographers interested in the history of Japanese geographical thought, under the stimulus of world-wide new trends in which the history of geographical thought is studied as a part of intellectual history or the history of science. Here, the term “geographical thought” connotes not only geographical ideas or theories of professional or academic geographers but also ideologies and conceptions concerning the spatial relationships and geographical environments of specialists other than geographers and of the common people. Geographical thought in this broader sense has been expressed not only by means of languages in the narrow sense of the term (langue) but also by other means of expression (langage) such as the pictorial or the cartographical or that of spatial planning. Having specified the fundamental stance as quoted in the above title, the organisers next requested papers for presentation at the symposium, tentatively proposing the following six main topics:
1. Diffusion and successive transmission of indigenous and/or traditional thought in Japan and East Asia and the continuation or non-continuation of this traditional or indigenouse thought into modern Japanese geography after the Meiji period.
2. Diffusion and acceptance of geographical knowledge and geographical thought of Western origin in pre-modern Japan, their articulation with modern geography in Japan and various transformations.
3. Geography and geographical thought in the Meiji period prior to the establishment of academic geography in Japan.
4. Founders of the academic geography of Japan, their successors (orthodox geographers), innovators in academic geography and “outsider” geographers.
5. The sociology of geography as a sociology of science.
6. Relationships (involving acceptance, refutation or influence) of the Japanese national school of geography with foreign geographical schools or foreign geographers.
In response, the following papers were contributed: Unno, K. (Osaka University): Conceptions of the Early Modern Japanese regarding their own Nation.
Naito, M. (University of Tokyo): Changing conceptions of soil and water (suido) in the agronomical books of the Early Modern Period: from adaptation to the environment to transformation of the environment.
Kamozawa, I. (Hosei University): Why there were no successors within the academy to the geographical thought of the Meiji enlightenment thinkers.
Ashikaga, K. (Kyoto University): Historical geography of the Early Showa Period.
Nishikawa, O. (University of Tokyo): The geographical methodology of Taro Tsujimura (1890_??_1983).
Yatsu, E. (Joetsu University of Education): A personal view of geomorphological studies in Japan, especially between 1940_??_65.
Ishimitsu, T. (Kobe University): Doctor E. A. Ackerman and Natural Resource Polcies under the Allied Forces Occupation.
Tatsuoka, H. (Tokyo Metropolitan University): The acceptance of R. Hartshorne in Japan.
Yamada, M. (Osaka Kyoiku University): Diffusion processes of the so-called New Geography in Japan.
The paper session and general discussion were presided over by K. Nakamura (Komazawa University), M. Senda (Nara Women's University), Y. Otake (Joetsu University of Education) and H. Nozawa.
Unno pointed out that in comparison with the rather pessimistic conception of Japan under the influence of Buddhist cosmology in the Mediaeval period, the conception of Japan in the Early Modern period was characterised by an optimistic view evidenced by the admiration of the Japanese people for their own land. N. Honi (Hiroshima University), in the capacity of commentator on Unno's paper, pointed out the egocentric political intentions of the rulers of Early Modern Japan who had seclusionism as their political target and confucianism as their ideology.

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