Large scale rice cultivation in Hokkaido made rapid and remarkable development in the years around 1932. For this progress the Doko Kumiai, or the associations for the construction of irrigation system for the rice fields played an important part. The system of the associations was legalized in 1902, and they received financial support from the national government. With the exception of some old rice lands in the southern part, most of the rice growing areas in Hokkaido received the service from this system.
Considering the processes of the establishment and the areal distribution of the associations, we can get a general view of the regional developments of rice cultivation carried out through the achievements of extensive irrigation systems.
Upon studying the materials the present author pointed out the following facts in this paper.
1. The regional development of extensive rice cultivation in the early years was not a universal spread towards the north, but started from two base regions: namely the Kamikawa Basin and the east part of Ishikari Plain-the present core regions of rice cultivation.
2. The remarkable increase of the rice fields in the several years following 1900 was brought about by the accumulation of small scale reclamations into rice fields, and the rapid expansion of rice fields by the completion of large irrigation systems. There were only small scale reclamation works in south Hokkaido which resulted in the dilatory increacse of rice fields. While in Kamikawa and Sorachi Districts the completion of large scale irrigation systems contributed to the rapid expansion of rice fields.
3. While far-reaching expansion had been made into several remote areas, an internal progress also made within the very core region. After 1920, the reclamation works made a tremendous development in east Hokkaido, while in the core region during the same period, many areas in the hilly and peaty lands were reclaimed into rice fields.

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Local-towns are susceptible to the influence of their surrounding areas, especially in recent days the influence of large cities became stronger. It is an interesting problem to analyse the way in which local-towns adapt themselves to their circumstances. In addition to this, their industrial development in recent years also became an important function. I will explain these aspects taking Motomiya and Nihonmatsu in Fukushima Prefecture as examples.
The main objects of this study is their function as service-centers, their relationship with their neighbouring cities in retail trades and in commuting, as well as their industrial production.
As the indices of a service-center the author used the development of the regular bus service, the sphere of retail trades, the scale of wholesale shops, and the kinds of administrative offices, schools and hospitals. Motomiya is inferior as the service-center. In retail trades, the influence of Koriyama is penetrating strongly into Motomiya's domain. In commuter-traffics, the commuters from Motomiya (out-commuters) go out chiefly to Koriyama, Fukushima, and Nihonmatsu. So I concluded that Motomiya was under the intense influence of these cities. Nihonmatsu is superior as a service-centre. In retail trade, the influence above-mentioned cities is not so vigorous as to Motomiya. In commuting, the destinations of out-commuters are not only Fukushima and Koriyama but also the neighbouring local-towns and villages. So Nihonmatsu seems less dependent on larger cities.
The commuters into local towns (in-commuters) come mostly from their neighbouring villages and are chiefly employed in manufacturing factories or transportational and communicational institutions. From these, I consider that there is a nodal-region having a local town as its functional center. Considering the ratio of in-commuters to total population, the figure of Motomiya is higher than that of Nihonmatsu. This suggests that Motomiya has larger economic capacity to accept in-commuters, which also means that Motomiya has larger industrial productivity. After all, Motomiya is stronger in industrial productivity, and Nihonmatsu as a service-center.
I examined, next, how these different characteristics of the two towns are reflected on their urban growths. As the indices of urbanization, I adopted the number of the employees in service occupations (for example, Laundries, Barber shops, Restaurants), and the length of main shopping-streets.
Judging from these indices the degree of the urbanization of these two towns seems almost the same. These two towns with their different personalities, have attained about similar degree of urbanization.

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Rebun Island is situated off the northwestern coast of Hokkaido, Japan. There are three erosion surfaces in this island, and their apporoximate heights are 300m, 20m, and 160m.
There are also three marine terraces-Kahuka Terrace, Benzaidomari Terrace, Horodomari Terrace in this island, and their approximate heights are 120-100m, 80m, and 40-30m respectively (Fig. 3).
The writer found that these terraces are widely developed both in the northern and southern parts of the island, but they were less remarkable in the central parts. At the Kaneda Cape and the Sukoton Cape situated in the northernmost districts of this island, marrine terraces make distinctive development.
Between the Kaneda Cape and the Sukoton Cape, some of the marine terraces are somewhat inclined. The geological construction of this island has a close connection with the development of the marrine terraces.
Among the terraces, the lowest one has the widest distribution and is well preserved. This consists predominantly of rounded gravels of slate, with the thickness 3m to 0.5m.
The upper surfaces of the bed rocks at the lowest terrace, vary from 20m to 9m, in height.

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The accumulation terraces consisting of pumiceous materials from the Tadami Valley are distributed in the valley along the upper course of the Aagano River, making a noticeable feature of the valley. The author tried to make clear the following facts on the relations between the accumulation terraces and terraces of other origin from his survey.
(1) In this region the terraces are classified into three groups; the higher, the middle and the lower terraces. The surfaces of the middle terraces are subdivided into four groups; P, P', M and M' Surfaces. P and P' Surfaces are the surfaces of the accumulation terraces consiting of pumiceous materials ejected from Numazawa Volcano. The accumulation of the pumiceous materials in the different parts of the previous valley floor occurred separately, making the narrow gorges its temporary base-levels. Consequently the longitudinal profile of the P Surface is discontinuous at the gorges and intersects the profile of the M Surfaces.
(2) The structures of the terraces can be devided into four types (Fig. 3). The surfaces of the lower terraces at A and B types reappear at the previous valley bottom. The surfaces of the lower terraces are lower than the bottom of the valley at the C type.
(3) Through the structural study of the terraces the author considers that the tectonic movement influenced the construction of the terraces in this region.

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The writer studied the free meander in the flood plains of the Iwaki, the Yoneshiro, the Omono, the Mogami, the Kitakami, the Natori, and the Abukuma rivers by the analysis using aerial-photographs and topographical maps, and by hydrological data and field investigation. The following points are his conclusions.
1. The meander rates of 1 > ρ≥ 0.80 (ρ: meander rate = (L-W)/L, L: meander wave length, W: meander wave width) are seen in the most downstream and the most upstream reaches of the flood plains. The meander rates of ρ<0.80 are found the reaches of midstreams. Free meander develops well in this part. These facts correspond with the results of experiments in model channel reported by Friedekin etc.
2. The development of meanders in these main rivers under consideration are greatly affected by their tributaries. The facts also correspond to the results obtained by the experiments.
3. In each of the flood plains, the present river in which meander develops runs through the area with numerous meander scars and meander scrolls clearly and widely preserved.
4. Observing the meander scars and meander scrolls in the flood plains, it can be pointed out that these river channels have been shifted by means of cut-off-meander in the river reaches with the meander rates of ρ<0.80, as well as the fact that shifting is a lateral vibration between nodal points, and nodal point coincides with the confluence of each river or valley mouth. But in river reach with the meander rate of 1>ρ≥0.80 these river channels have shifted with a pendulum motion like a river on an alluvial fan.

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