地学雑誌
Online ISSN : 1884-0884
Print ISSN : 0022-135X
ISSN-L : 0022-135X
102 巻 , 1 号
選択された号の論文の12件中1~12を表示しています
  • 萩原 幸男
    1993 年 102 巻 1 号 p. 1-12
    発行日: 1993/02/25
    公開日: 2010/10/13
    ジャーナル フリー
  • 内田 和子
    1993 年 102 巻 1 号 p. 13-27
    発行日: 1993/02/25
    公開日: 2010/10/13
    ジャーナル フリー
    Sajigawa Flood Prevention Cooperative is one of the few cases that work actively even at present. The author intended to clarify its characteristic activities to promote prefectural river improvement works and its pecuniary mechanism to support its activities.
    Sajigawa Flood Prevention Cooperative was originally organized to bear a considerable portion of outlay for river improvement works allocated its area. But prefectural works were stopped, because the cooperative failed in settling disputes with the lower reaches on burden of expenditure. After the failure, the flood prevention works were eventually realized with national financial aid by its active and continuous petitions to Hyogo Prefecture and national government. Thus active petitions became one of the most important and main works of the cooperative hereafter.
    The other important activity of Sajigawa Flood Prevention Cooperative was to substitute partially for prefectural government as land expropriation agent. Hyogo Prefectural Government easily bought up the land for river improvement works and promoted its works through the agency of cooperative.
    Financial source of the cooperative consisted of cooperative dues, contributions from adjoining municipalities and land expropriation payment. Cooperative dues consisted of those imposed on land and house individually in proportion to flood damage and those allocated equally to municipalities consisiting the cooperative.
    After 1969 when adjoining municipalities entered the cooperative, cooperative dues changed into those imposed to four towns consisting the cooperative in proportion of river length. Hence individual dues were abolished after 1969.
    Contributions from adjoining municipalities aimed to expand prefectural flood prevention works into adjoining area through active petitions of the cooperative. But these contributions stopped, because adjoining municipalities incorporated into two towns consisting the cooperative.
    Land expropriation payment was that land owner payed one percent of selling price to the cooperative in case of land expropriation substituted by the cooperative. This system abolished because of complication derived from land expropriation payment of adjoining municipalities.
    As mentioned above, characteristics of Sajigawa Flood Prevention Cooperative are unique. These characteristics were formed by some causes as follows.
    1. Sajigawa Flood Prevention Cooperative did not need to bear large amount of cost allocated by prefecture, because prefectural flood prevention works were realized with national aid.
    2. Another financial sources except cooperative dues were avail able: contributions from adjoining municipalities and land expropriation payment.
    3. Most members of the cooperative were sma llholders, especially of cultivated field. They could not pay large amount of dues, because they could not earn large profits from their field.
  • 伊藤 貴啓
    1993 年 102 巻 1 号 p. 28-49
    発行日: 1993/02/25
    公開日: 2010/10/13
    ジャーナル フリー
    Under the rapid economic development in which areal differentiation has proceeded among main vegetable producing areas in Japan, the traditional truck farming areas have suffered from competitions from the new suburban producing areas, by developments in plastic greenhouse as well as environmental control technology. Although interregional competitions for predominant position with major urban markets have come to be more and more enhanced, some traditional producing areas have occupied the advantageous position in central wholesale markets.
    This study examined how the traditional vegetable producing area have managed to survive in marketing competitions. Toyohashi City in Aichi Prefecture, the origin of glasshouse horticulture on commercial base in Japan, was selected as the study area. After describing some features of garnish production area, the development of glasshouse and plastic greenhouse horticulture were examined through the technological innovation, the organization of cooperative shipment, and the marketing competitions with new producing areas. Then, the development system and the regional base of its system were discussed.
    The farms are concentrated in the built-up area and its fringe of Toyohashi city. In response to urbanization, the farmers introduced industrial production mode into agriculture. As a result, garnish cultivation resembles manufacture in the mode of production, the organization of labor, and the orientation of farm management. Garnish cultivation in Toyohashi is a typical form of industrialized agriculture. The farm operation are characterized by the intensification of land, labor, and capital. The area is characterized by many farm households with one or more male regular farm workers, the high ratio of farm households with inheri-tors, farms with intensive labor forces, and the farms with large sales. On the other hand, the garnish cultivation is characterized by truck farming in cooperative shipment for the met-ropolitan areas. The glasshouse.
    The glasshouse production originated with a pioneer in 1901. Farms in lower Toyo River depended until the 1920s on sericulture and production of cereals for earning. The glasshouse production replaced sericulture with the Agricultural Crisis in 1930s. Since then, vegetable production in glasshouse has been developed and the Agricultural Cooperative Asso-ciation has been organized. In 1947 production of denshogiku (Chrysanthemum) started inthe study area. Toyohashi was the center of tomato and denshogiku production in Japan until early 1950s. Tomato production in this area suffered from competition in central wholesale markets with new truck farming areas along the Pacific Ocean. On the other hand, denshogiku production of Atsumi Peninsula has remarkably developed in 1950s. In 1960 garnish was introduced as key crop from Osaka.
  • 久保 純子
    1993 年 102 巻 1 号 p. 50-59
    発行日: 1993/02/25
    公開日: 2010/10/13
    ジャーナル フリー
    The World Bank has made “Bangladesh Action Plan for Flood Control” which consists of 26 components after severe floods of 1987 and 1988. Japanese and UK governments donate the Component No.2, for Northwest Region. The author attended the preliminary study in 1990 as a geomorphologist and found some problems on flood mitigation projects related with characteristics of landform and flood feature.
    The northwest region is divided into the following four geomorphological units: 1) Barind Tract, 2) the Himalayan piedmont plains, 3) the Alluvial lowland along the Brahmaputra-Jamuna and 4) the Alluvial lowland along the Ganges. The embankments are frequently broken by floods because river beds are unstable in the Himalayan piedmont plains. In the alluvial lowland along the B.-Jamuna, the river channels are unstable and change their courses frequently during annual floods with breaching embankments, since the B.-Jamuna changed its course in the 18th century. In the alluvial lowland along the Ganges, distinct large natural levees have developed along the Ganges and a broad back-marsh area lies along the lower Atrai Basin. The “Polder Project” for flood protection is progressing in the lower Atrai Basin. However, each polder is too broad to protect the whole area. In order to protect their houses, people often cut embankments for draining inundation water not only from inside of the polder to river, but also from outside of the polder into the protected area.
    In the Flood Action Plan, the World Bank proposed two major projects in this area, namely, an interceptor drain from the Upper Atrai into the B.-Jamuna, and a diversion channel from the Lower Atrai into the Ganges. The main technical problem on both the Interceptor and the Diversion channel is the water level at the outfalls. The Interceptor is proposed along the Karatoya-Atrai, a heavy free-meandered river. The Interceptor needs high embankments whole from the Atrai to the B.-Jamuna. The Diversion channel is less feasible ; since the river bed of the Atrai is lower than that of the Ganges.
    Apart from these major projects, the author suggests smaller but reasonable projects for this area. In the southern part, the Polder Project is to be improved: smaller units of polders with consideration of geomorphological setting and local land-use conditions. A comprehensive project which contains both structural and non-structural methods for flood control and rural development programs as waterside district will support the development of this area.
  • 渡辺 悌二
    1993 年 102 巻 1 号 p. 60-72
    発行日: 1993/02/25
    公開日: 2010/10/13
    ジャーナル フリー
    The air-photo interpretations and the casual field observations in the Navajo Glacier area, the uppermost reaches of the South St. Vrain Creek, Colorado Front Range, led to the speculation that the Triple Lakes “protalus ramparts” which were identified by Benedict (1968) can be classified into the following three different landforms:(1) a ridge located at the highest altitude (U1) regarded as a protalus rampart, while another in the center can be subdivided and classified into (2) a protalus rampart (U2: upper unit) and (3) a lateral moraine (L: lower unit). Several lines of evidence support the above classification. Firstly, the lower unit (L) has a flat surface with vegetation cover. Secondly, the lower unit (L) continues to an arcshaped ridge downvalley. Thirdly, the upper unit (U2) has the same sinuosity as that of U1 and the talus slope but the lower unit (L) does not. Finally, the lower unit (L) has fine matrix whereas the upper unit (U2) does not.
    Multiple relative dating methods, such as lichenometry (lichen diameter, percent lichen cover, and ratio of green lichens/{brown and black lichens}), weathering rind thickness, SGW I (surface granite weathering index of Benedict, 1985), and pit depth, provided the estimated age of Triple Lakes (3, 000-5, 200 y. B. P.) for both the moraine and the protalus rampart classified above. However, soil profiles and soil color indices (Buntley-Westin and Hurst color indices) indicate that the moraine is older than the protalus rampart. It is probable that the lichenometric and weathering feature data collected from the lateral moraine surface have been influenced by rockfall activity which modified the moraine surface during the Triple Lakes period. The protalus rampart (U2) is estimated to have been formed in the Triple Lakes Stade, as Benedict (1968) states. However, the moraine seems to be of the Satanta Peak Stade (10, 000-12, 000 y. B. P.), which is recognized elsewhere in the Colorado Front Range (Birkeland et al., 1987).
    Using this result together with the method for estimating glacier ice thickness of Porter et al.(1983), this study has also attempted to reconstruct the Navajo Glacier in the Late Stade of Pinedale and the Satanta Peak and Triple Lakes stades. The glacier is believed to have terminated at an altitude of 3, 250-3, 300m in this valley in the Late Stade of Pinedale (-14, 000 y. B. P.)(Madole, 1969), at which time the area and thickness of the glacier are estimated to have been 5.6km2 and 250m, respectively. In the Satanta Peak Stade (12, 000-10, 000 y. B. P.), the glacier retreated to 3, 480m, and its area and thickness decreased to 1.0km 2 and 100m, respectively. The Triple Lakes glacier terminated at an altitude of 3, 680m in the cirque, with an area of 0.2km 2 and a thickness of 25-30m.
  • 鈴木 毅彦
    1993 年 102 巻 1 号 p. 73-90
    発行日: 1993/02/25
    公開日: 2010/10/13
    ジャーナル フリー
    The purpose of this paper is to present the stratigraphy, distributions and characteristic properties of tephra layers around Nasuno Plain in North Kanto, central Japan. This tephrostratigraphical study is carried out as a basic work for the applicative tephra study which will contribute to volcanology and Quaternary study of this region in late Quaternary.
    43 tephra layers deposited in the latter half of middle Pleistocene are identified. The tephra layers derived from nearby volcanoes located in North Kanto are as follows; 12 tephra layers from Nasu Volcano, four tephra layers from Takahara Volcano, 17 tephra layers from Nikko Volcanic Group and one tephra layer from Akagi Volcano. Two widespread tephra layers named APm-U and APm-L (300-350 ka) derived from Momisawadake Volcano in the Hida Mountains are identified. However, the sources of seven tephra layers remain unknown. Ages of these tephra layers are estimated to be younger than 400 ka on the basis of thickness of volcanic soil and ages of several dated tephra layers.
    On the other hand, 32 tephra layers formed in late Pleistocene are described. They include the following five well-known widespread tephra layers, that is, AT (22-25 ka), DKP (48 ka), Ng P, Aso-4 (86-90 ka), On-Pm I (80-95 ka). They are derived from distant volcanoes locating in central and southwest Japan. At the same time, 25 local tephra layers from Akagi, Nasu Volcanoes and Nikko Volcanic Group are recognized.
  • 吉田 明夫
    1993 年 102 巻 1 号 p. 91-94
    発行日: 1993/02/25
    公開日: 2010/10/13
    ジャーナル フリー
  • 新藤 静夫
    1993 年 102 巻 1 号 p. 95-96
    発行日: 1993/02/25
    公開日: 2010/10/13
    ジャーナル フリー
  • 小泉 武栄
    1993 年 102 巻 1 号 p. plate1-plate2
    発行日: 1993/02/25
    公開日: 2010/10/13
    ジャーナル フリー
  • 小泉 武栄
    1993 年 102 巻 1 号 p. plate3-plate4
    発行日: 1993/02/25
    公開日: 2010/10/13
    ジャーナル フリー
  • 久保 純子
    1993 年 102 巻 1 号 p. plate5-plate6
    発行日: 1993/02/25
    公開日: 2010/10/13
    ジャーナル フリー
  • 渡辺 悌二
    1993 年 102 巻 1 号 p. plate7-plate8
    発行日: 1993/02/25
    公開日: 2010/10/13
    ジャーナル フリー
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