Since modern embankments were built along the main river in Shizuoka Prefecture, much of the river bed has risen higher than the neighbouring plain. But the post-war construction of dams has sharply decreased the drift supply to downstream. Moreover, the increasing demand for gravel as construction material has led to the removal of a great deal of gravel, resulting in the rapid lowering of the river beds in recent years. This lowering of river beds and underground water level have produced various changes in the water utilization and the land utilization of the river basin in line with geological features which are characteristic of an alluvial fan.
The eel cultivating area of the Oi river's downstream is not an exception; namely, the eel cultivating operation which had been established in the disused paddy fields along the Oi River led to the management practice of cultivation by exchanging water, making use of the spring water and the sloping land. Later, after overcoming the water shortage and the problems of pollution, this area developed into the largest eel cultivating area in Japan.
Thus, the influence of water supply on establishing productivity deteriorated in the downstream area of the Oi River. However, this change for the worse gave us an important opportunity to accellerate the establishment and development of eel cultivation. On the other hand, the increased demand for drinking and industrial water which kept pace with the increase of eel cultivating ponds brought about increased competition between them.
Faced with the increased demand for drinking and industrial water, eel cultivators tried unsuccessfully to get water rights. Their lack of success may be due to the fact they were snarled in national and prefectural bureaucratic procedures as well as in the peculiar local problems relevant to water rights.
In the eel cultivating area in the downstream of the Oi River, with Yoshida-cho on the right side of the river, and Oigawa-cho on the left side, we find an asymmetrical development of the geographical distribution of eel cultivating ponds and the significance of eel cultivation with respect to the industrial structure of these two towns.
The differences between the two towns may be traceable to the differences of so-called historical conditions governing their formation as well as the differences of their geological features.
Thus, these differences, which determined the extent of competitive utilization of underground water of both eel cultivating areas, and the consequent change in the attitude of eel cultivators of the local authorities, have become the main reason for the recent switchover to the use of ponds for eel cultivation.

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Migration is one of the most interesting subjects not only in demography but also in geography. When we consider the origin and destination of migration, we find that urban areas are of great importance. Especially the center of the metropolis has a lot of mobile people and many out-migrants. We can distinguish three typical patterns of migration from the center of the metropolis: decentralization in the metropolitan area, migration to another metropolises and return to their native places. But the intensive studies on intraurban migration, interurban migration and urban to rural migration like a so-called “U-turn” phenomenon have not been done well.
In this article, the writer adopted Naka-ku, the center of the Nagoya metropolis, as a research area. Its objects are 7, 852 out-migrants from Naka-ku in 1972 whose names were struck off a resident registration's list. They are equivalent to about 60% of all the out-migrants from Naka-ku in the year. The data for this study are sex, age (5-year groups), duration of residence, destination and origin (before Naka-ku) of out-migrants, and date and type (personal or family) of out-migration. The objectives of this paper are to recognize the features of out-migrants and migration process and to understand the constitution of migration from the center of the metropolis.
The features of out-migrants shown in tables 3∼4 are summarized as follows.
(1) The mobility of man is higher than that of woman.
(2) Out-migrants consist chiefly of young people from 20 to 34 years old and in case of personal migration this trend is more remarkable.
(3) Generally speaking, the duration of residence is very short, and out-migrants whose duration of residence is less than three years are the greater part of the whole. In case of family migration it is pretty longer than in case of personal migration. And the longer the duration of residence is, the larger the family is.
Then the features of out-migrants viewed from each destination are shown in tables 5∼7.
(1) Most of out-migrants are short-distance migrants and more than 70% of them moved out to three prefectures of Tokai districts (Aichi, Gifu, and Mie Prefectures). Applicating the gravity model to the relation between distance and the number of migrants, the restriction of distance is comparably weak.
(2) In case of family migration, short-distance and interurban migrations are more frequent than in case of personal migration. The longer the distance is, the smaller the family is and, at the same time, the shorter the duration of residence is.
(3) In case of personal migration, the longer the distance is, the greater the number of young people is and the shorter the duration of residence is.
By the way, it is one of the most important subjects in this study to analyze the migration process. The results viewed through the analysis of the relation between the destination and the origin of out-migrants are as follows.
(1) There are many out-migrants whose destination and origin are entirely the same or near areas. About half of the long-distance migrants are recognized as so-called “U-turn” migrants who came to metropolitan areas from rural areas for working or studying and returned to the same or near areas for working. Therefore we can identify the existence of a so-called “U-turn” phenomenon.
(2) “U-turn” migrants are mainly composed of young people from 15 to 29 years old whose duration of residence is very short.
(3) In case of intraurban migration, there are also many out-migrants whose destination and origin are the same or neighboring places (ku). The ratio of outmigrants, who moved out for the first time, to intraurban out-migrants is a little high and their mobility is not high. Then Intraurban migration patterns are pretty complexed by many factors.

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The aim of this theme is to find out a clue to the disclosure of the reclaimed land in the middle reaches of the Kino River, but its chief purpose is firstly to make a restorative research of the ancient land development or “jori chiwari” (land division) and secondly to restore the ancient landscape of the area. The area of this study is the middle reaches of the Kino River (Naga County) where the jori restoration still remains unrevealed.
The methods of study are;
1) drawing up of a map of the jori land division. 2) naming of the jori land division and finding out the possible location of Akinano-sho area. 3) jori land division and the topographical conditions. 4) its retation of irrigation. 5) the relation of “jori” with the Kokubunji Temple and with “go”.
(1) The distribution of jori in the middle reaches of the Kino River can be roughly parceled into 7 blocks. (Fig. 1, A∼G jori sections)
In the northern part of the river the main “jori” is made up of, the easy slope on the periphery of the composite fan which extends to the southern foot of the Izumi Mountains and the lower terrace. (Fig. 4)
In the southern part of the river, we also can find the remains of such jori in the flood plain of the Kishi River, a branch stream of the Kino River.
“jori” in the Kii Mountainous district extends as far as the Nogami Hachiman Shrine.
(2) In the north, the direction of “jori” way of land division adopts the Seihoi (ditches of land are in the direction of North, South, East, West) with the Kokubunji-Temple as its center.
In the upper reaches the maximan propencity is N14°W and in the lower reaches, N7°E. (Fig. 1)
But as a whole, the dircetion of the land division takes un-“seihoi” taking the shape of a fan.
This was influenced by the direction of the fan-shaped land on the northern bank.
But there are frequent occasions of each “jori” being in succession.
Each “jori” has the uniform characteristic in the north, while in the south “jori” is fragmentary.
It is clear that they divided the land by the unit of 1 “cho” (section) (Fig. 2) but in the inner part can we sea many indefinite and irregular shapes.
Only in the fan-shaped area, “haori”-shape variation and in the lower terraces “Nagaji”-shape variation are found.
(3) In the north, the upper reaches (Ito) and the lower reaches (Nagusa) have the same way of naming, that is, “jori” is divided into 25 “zu” (jo) from east to west, 7 “ri” from south to north.
The land belonging to the Kanshinji Temple and Akina-sho (a feudal manor) in the ninth century is presumably the “Shoiki”.
This investigation will disclose how the alluvial fan was reclaimed in Heian period, how “jori” was named in the Kahoku district, and provide basic material concerning archaeological views.
It is presumed that they adopted the way of naming based on “block”.
(4) As to the irrigation of “jori” paddy in the fan, in case of the basin of the Negoro River, the irrigation by the erosional valleys and ponds are thought to be old irrigation forms.
(5) The 2 square “cho” domain belonging to the Kiikokubunji Temple adapts the “seihoi”. And the boundary of the temple domain connects with the jori in the vicinity with the transitional type. (Fig. 6)
(6) The presumption of the location of 7 “go” of Naga county written in the “Wamyosho” will be submitted as a tentative plan (Fig. 2), taking the connection with the block “jori chiwari” into account.

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