Islands have many problems due to their isolation and many islands lack domestic water for everyday use. However, there are few studies of forms of water intake and water use in such islands. Such research is necessary.
The study regions in the present research are the Nada Area of Nandan Town, Mihara County and the Kaminada Area of Sumoto City. These regions are situated on steep slopes at the southern foot of the Yuzuruha Mountains in Awajishima Island and the different water intake and water use in each village have been evolved according to the geomorphological conditions. The aim of this research is to clarify forms of domestic water intake and changes in the spatial structure of water utilization in the region where water utilization conditions are unfavorable.
This research is summarized as follows:
1. There are 5 types of water intake as shown in Table 1. Type A: in which water is diverted from mountain streams cooperatively and a small water supply system functions for the exclusive use of the village. Type B: in which water intake from mountain streams is carried out by individual households. Type C : in which water intake is from a spring (called Kawa or Hori) or a well. Type D: in which water is distributed from a town-managed small water supply system, and type E: in which water is diverted from an irrigation pond.
2. Type A water intake is being used in 14 out of 17 villages and type D is being used in 2 villages. One village is situated in a transition zone between type A and type D and uses types B, C and E.
3. Type A water intake is further classified into 2 type: A₁ type having many water utilization groups in a village and A₂ type having only one water utilization group in a village. A₁ type occurs in 6 villages and A₂ type in 8 villages.
4. Due to the geomorphological conditions that houses locate dispersedly on small marine terraces, type A₁ is seen in Yudani, Yamamoto and Sogawa. Type A₁ occurs due to social factors that social groups originate wate rutilization groups and is seen in Yoshino, Kuroiwa and Shirosaki. In 3 villages where many water utilization groups are formed by such social factors, water intake is taken per Rinpo which is a small territorial group and has various social functions. It is thought that in Yoshino and Kuroiwa the distribution of Rinpo is strongly influenced by the topography. In Shirosaki, 2 water utilization groups are formed by 2 Rinpos which hold conflicting views on water utilization methods. So only these water utilization groups in this village can be said to be formed just by social factors.
5. The reason why many water utilization groups are not unified as one group is that it has not been necessary to alter the forms in the water utilization until now, even in order to meet high costs for construction, so long as no drought occurs. When a drought occurs, water utilization groups may become unified, as in the case of the village of Shirosaki.
6. In type A₂ joint diversions of domestic water, no clear-cut rules concerning utilization procedures, distribution, and maintenance labor exist such as are found in agricultural water utilization groups. To a certain degree, however, a management rule is established, since facilities in this form often break down. For example, persons on duty for the water work are selected and these persons manage the water works facilities. When things break down on a large scale, all households contribute to repair works. There are villages which collect expenses for repairs every month. Further, with respect to the source of water supply, the degree of distress in a dry period is quite different between villages which have the water right on the mountain stream and those that don't, have it. Such villages as Habu have often changed the source of their small water works.

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In the recent fifty years many studies on recent formations have revealed their sequences of sedimentation and the palaeogeography of the coastal plains in Japan. These studies, , however, set the time of lowest sea-level in the Lastglacial age for the beginning stage. Inn such a way of study the development of the coastal plains during more longer period hass rarely been discussed or clarified on the basis of adequate geomorphological evidences.
In this paper the author aimed to reveal the geomorphological development and the change in the volume of the sediments in the coastal lowland since the Last-interglacial epoch. The North Ariake Bay Lowland was chosen for the study area because (1) the tectonic movement has been clarified and (2) the Aso-4 pyroclastic flow deposit of ca. 70, 000y. B. P, can be used to calibrate the time scale.
First, the stratigraphy was classified by analyzing about 600-borehole data with geomor-phological care (Fig. 3-A). Based on this stratigraphy the geomorphological development was clarified as follows (Figs. 10 and 11 (left) ):
1. A flat plain was formed in the course of the Last-interglacial transgression. The plain has been depressed at a rate of 0.2m/1, 000y., and buried at -20m as the dissected surface.
2. After the transgression, the sea-level had lowered, rised, and then lowered again by a time of the Aso-4 pyroclastic flow deposition (ca. 70, 000y. B. P.). In this course of the sea-level change a river terrace was formed and then dissected by rivers. The river terrace surface was tephrochronologically correlated to the Obaradai surface in South Kanto.
3. The Aso-4 pyroclastic flow deposit erupted from Aso volcano, about 80km southeast of the study area, covered the former landform mentioned above with an almost uniform thickness of about 10m, remaining the former relief energy on the landform surface.
4. The fine sediment, denoted as PS in this paper, was accumulated at a place where the surface of the Aso-4 pyroclastic flow deposit was lower than -20m, to form a flood plain. The age of this stage was estimated at ca. 30, 000y. B. P., the Interstadial stage in the Lastglacial age.
5. At the stage of the lowest sea-level in the Lastglacial age the rivers cut down the former surfaces by 5 to 10m vertically.
6. During the latest Pleistocene transgression the lower recent formation was accumulated to form two alluvial fans and a flood plain. These depositional landforms were then dissected during the following period of regression.
7. During the Postglacial rise of the sea-level the upper recent formation was accumulated to form the present extensive flat plain.
Based on this geomorphological development the author aimed to quantitatively estimate the effects of sedimentation, erosion and subsidence. The volume of each sediment was calculated from the thickness, the basal depth, the distributed area, the form of valley, etc., considering the palaeogeography (Fig. 11). These results were depicted in the volume-time diagram (Fig. 12). After the formation of the flat plain in the Last-interglacial epoch, the subsi-dence continued gradually during the Lastglacial age to build the basin for the deposition of the recent formation. The total amount of subsidence has reached 6.4km³ during the last 120, 000y. The Lastglacial age was also characterized as the tractional stage with higher potential of sedi-mentation, as seen from the deposition of the recent formation, compared with the erosion which actually occurred. The recent formation has been accumulated rapidly with a volume of 5.2km³; this amount compensates about 80 per cent of the subsidence mentioned above.

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The purpose of the present paper is to reveal the distribution and change of voting returns in the elections to the House of Councilors (National Constituency), and to examine the relation between the voting returns and regional socio-economic characteristics in Aichi Prefecture. For that purpose, (1) voting ratios and polls to each political party were calculated in order to examine the distribution and change of voting returns between the 7th election (1965) and the 10th election (1974), (2) factor analysis was applied to 38 variables selected for regional socio-economic characteristics and their changes in Aichi Prefecture both in 1965 and 1975, and (3) the relations between factor scores and voting returns were analysed by multiple regression analysis. The study area contains 101 wards, cities, towns and villages in Aichi Prefecture (Fig. 1).
The results obtained from these analyses are summarized as follows:
1. In the 7th election, the voting ratio was higher in rural and mountainous areas and lower in urban areas, which was also the tendency held in the 10th election (Fig. 2-a, b). The polls of the Jimin Party (Liberal-Democratic Party, L. D. P.) were more numerous in rural and mountainous areas and less so in urban areas in the 7th election. The polls of the L. D. P, decreased in the 10th election (Fig. 2-c, d). The percentage of polls of the Shakai Party (Japan Socialist Party, J. S. P.) were higher in urban areas in the 7th election, because the J. S. P. was supported by a number of labour unions. The J. S. P.'s polls decreased, however, in urban areas in the 10th election (Fig. 2-e, f). The Komei Party, the Minsha Party (Democratic-Socialist Party, D. S. P.) and the Kyosan Party (Japan Communist Party, J. C. P.) secured more votes in urban areas than in rural and mountainous areas in the 7th election, and they received more votes from urban areas in the 10th election than in the 7th election (Fig. 2-g-1). The Komei Party and the J. C. P. won more votes in Nagoya City and its suburbs, and their polls increased there between the 7th and 10th elections. The D. S. P, is supported by such labour unions as fiber industries and the Toyota Automobile Company Ltd. and its allied companies. Therefore the D. S. P, polled more votes where those companies were located than other areas.
2. Eight factors for 1965 and nine factors for 1975 were extracted by the factor analysis. Based on the eigen values above unity, the cummulative percentage to the total variance was 83.8% and 85.4% respectively (Tables 2 and 3). The maj or dimension thus extracted was employment types (38.1%) for 1965, which had high factor loading to many variables and showed general characteristics of urban-rural extent. As for 1975 some factors showing commercial activities as well as density, increase, and constitution of population had high percent of explanation. Those analyses suggest that industries have dispersed and the regional difference of the tertiary industries has become notable during ten years.
3. The results of multiple regression analysis suggest that there is a close relation between the voting ratios and the socio-economic characteristics (Table 4). As to the 7th election, the voting ratios were generally explained by the first factor, while the factors to explain the 10th election's voting ratios varied greatly from one party to another. Most residuals from the multiple regression model were explained by the organized polls of labour unions especially in J. S. P. and D. S. P. and by the personal polls of influential members.

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