地学雑誌
Online ISSN : 1884-0884
Print ISSN : 0022-135X
ISSN-L : 0022-135X
94 巻 , 1 号
選択された号の論文の8件中1~8を表示しています
  • 柴田 匡平
    1985 年 94 巻 1 号 p. 1-20
    発行日: 1985/02/25
    公開日: 2010/10/13
    ジャーナル フリー
    Minuma Land Improvement District (Minuma L.I.D.), Saitama Prefecture, is the agricultural water use organization in charge of Minumadai irrigation canal. The canal, excavated in 1728, has been functionning as the trunk waterway to irrigate more than 12, 000 hectares of farmland. Its length, some 60 kilometers, makes the canal still one of the biggest irrigation facility in present-day Japan. However, as the canal's beneficiary area is adjacent to, and partly incorporated into, the rapidly growing suburban area of Tokyo, both the canal's function and the organizational structure have undergone a considerable change, which the present paper deals with as its major topic.
    The second theme is the Minuma L.I.D.'s reaction when, in 1962, it was challenged by the administrative bodies for a curtailment of its water intake volume from Tone River. This demand was made to Minuma L.I.D. as a part of the plan of excavation of a new canal running water for drinking purposes and unification of six irrigation canals at intake. Minuma L.I.D., which had the biggest intake volume among the agricultural water use entities, was determined not to agree to the plan unless its traditional water intake volume would be secured. As it was one of the earliest cases where agricultural water rationalization became subject of public discussion, this attitude has since been put under an implicit criticism, i.e., in spite of the social need and decrease of beneficiary farmland, the agricultural water users are reluctant to spare their water out
    The author examined the budgetary structure of Minuma L.I.D. in the period of the recent 25 years and found the following points:
    1) Due to suburbanization, southern (down stream) portion of the beneficiary area of Minumadai canal, for which the canal was originally developed, has been almost completely absorbed within Densely Inhabited District (D.I.D.), where the canal functions now as drainage waterway of residual urban water;
    2) Minuma L.I.D. has merged several L.I.D.s whose areas either overlapped with or were adjacent to its own, notably in the north, thus shifting its financial basis from southto north;
    3) Financially, Minuma L.I.D. was experiencing a critical period at the time when it was asked to decrease its water intake volume, though the financial situation was remarkably improved afterwards, thanks largely to the money paid by the farmers converting their farmlands to urban land use.
    The points 1) and 2) mentioned above suggest that the canal's historic role has terminated and, more importantly, the area of L.I.D. is not to be regarded as identical with the area of water distribution. The former is essentially an institutional feature, while the latter must be defined from an engineering point of view. The point 3) indicates that financial situation could be a major factor when water rationalization is at stake.
    As many branch canals of Minumadai canal are maintained and operated by independent L.I.D.s which have no organizational link with Minuma L.I.D., Minuma L.I.D. was not, and still is not, enpowered to represent and manage the whole network of agricultural water distribution of the area. Taking this systemic characteristics and the point 3) above into consideration, the author concludes that the firm attitude adopted by Minuma L.I.D; in regard to the demand of decreasing its water intake volume is not to be attributed to the farmers' reluctance to give water away; its organizational situation at the time could provide another explanation.
    Author acknowledges Gil Latz, editor of “Contemporary and Historical Irrigation in Japan: Selected Terminology and Illustrations”, 1985, Toyota Foundation, for indicating appropriate English terms to be used in this abstract.
  • 浜田 隆士
    1985 年 94 巻 1 号 p. 21-33
    発行日: 1985/02/25
    公開日: 2010/10/13
    ジャーナル フリー
    An inhabited volcanic island of moderate size like Miyake-jima (8×9km approx.), which is located at about 200km south of Tokyo, would be a suitable site for an investigation of natural and social systems on an active volcanic island applying a transdisciplinary approach. A group study on this line in the University of Tokyo has commenced since 1981 with seven members who major in volcanology, paleontology and geological history, geochemistry, botany, ornithology, animal ecology, and coastal biology respectively, to establish a long-term study for coming ten years. In this circumstances, on October 3, 1983 the Miyake island erupted along a fissure which run in the caldera and on the flank ofthe old somma to reach the southern coast. One of the lava flows spilt over the caldera wall and buried the Ako area with more than 400 homes. The 4.5km long fissure eruption lasted about 13 hours at least, and some explosion craters were formed in the coastal region. An unusually remarkable fact is that fortunately no one was dead nor seriously injured with this 1983 Miyake eruption.
    Our group study immediately treated this volcanic activity as one of the transdisciplinary themes. This article contains some preliminary results of our investigation as follows:
    I. Preface, II. A transdisciplinary scope of the study on volcanoes, III. Characteristics the 1983 eruption, IV. Some remarkable facts observed: 1. Gust caused by a curtain fire, 2. Asymmetrical arrangement of ejecta from the fissure, 3. Subsurface coralline evidenced by the ejecta of phreatomagmatic explosions, 4. Sequence of phreatomagmatic explosions, V. Effects on the island flora and fauna by the eruption: 1. Bombing the ejecta, 2. Recovery and transition of vegetation after heavy ash disaster, 3. Impact the eruption on the avian fauna, 4. Submarine biotic communities, VI. Changes of social environment of the island for this past one year after the eruption, VII. A further scope the study.
  • 坂上 澄夫, 川辺 鉄哉, 石橋 毅, 長井 孝一, C. Raul CARRASCO, D. Angel ESCOBAR, Z. C&ea ...
    1985 年 94 巻 1 号 p. 34-44
    発行日: 1985/02/25
    公開日: 2010/10/13
    ジャーナル フリー
    As the third occasion of our biostratigraphic study in the Andean region, the field work was undertaken during middle July to late August, 1984. It was financially suported by the Overseas Scientific Research Fund in 1984 of the Ministry of Education, Japanese Government.
    The journeys in Bolivia and Peru are shown in Figs.1 and 2.
    In Bolivia, the columnar sections were made along some routes around Lago Titicaca, namely, Yaurichambi (the original locality by D'ORBIGNY, 1842), Cuyavi, Chirapaca, Yampupata, Ancoraimes and Matilde, where the Copacabana Group is well developed. Abundant fossils such as fusulines, bryozoans, brachiopods, corals and molluscs, were collected from these routes.
    In Peru, we had the field surveys to Mina Atacocha and Mi na San Vicente. In the Atacocha area, one route along slope at Machcan village was sel ected for measuring the lower part of the Pucara Group corresponding to the upper Triassi c Chambara Formation and 58 rock samples for conodont analysis were collected at intervals of about 5m. In San Vicente, some Jurassic ammonites were collected.
    These faunas have yet to be studied, but the paleontological and sedimentological studies will be made by each partakers.
  • 松田 磐余, 花井 徳寳, 望月 利男
    1985 年 94 巻 1 号 p. 45-53
    発行日: 1985/02/25
    公開日: 2010/10/13
    ジャーナル フリー
  • 大竹 一彦, 根本 寿男
    1985 年 94 巻 1 号 p. 54-57
    発行日: 1985/02/25
    公開日: 2010/10/13
    ジャーナル フリー
  • 赤桐 毅一
    1985 年 94 巻 1 号 p. 58-64
    発行日: 1985/02/25
    公開日: 2010/10/13
    ジャーナル フリー
  • 浜田 隆士
    1985 年 94 巻 1 号 p. 65-66
    発行日: 1985/02/25
    公開日: 2010/10/13
    ジャーナル フリー
  • 鎮西 清高
    1985 年 94 巻 1 号 p. plate1-plate2
    発行日: 1985/02/25
    公開日: 2010/10/13
    ジャーナル フリー
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