地理学評論 Ser. A
Online ISSN : 2185-1735
Print ISSN : 0016-7444
67 巻 , 11 号
選択された号の論文の6件中1~6を表示しています
  • 高野 岳彦
    1994 年 67 巻 11 号 p. 753-774
    発行日: 1994/11/01
    公開日: 2008/12/25
    ジャーナル フリー
    本稿では,仙台市を対象に近年の住民属性と居住分布の変化を考察した.1970年と1985年の国勢調査メッシュ統計を用い,分割メッシュを単位地区とし,DIDを対象範囲とし,34の住民属性指標を選択した.はじめに両年について因子生態分析を行ない,因子構造の検討から居住特性の変化の特徴を考察した.次いで各因子と関連の強い諸指標について地帯別・セクター別の分布を検討し,その変化傾向を把握した.見出された変化傾向は次の3点にまとあられる.
    (1)都心部に集中をみせる専門技術管理職層,逆に都心で減りつつある家族従業者・自宅就業者層,都心外への拡散を強める商業・販売従事者群,旧市街地における急速な民営借家化・単身世帯化・高齢化・少子化の進展,ブルーカラー層の著しい減少など,従来の「同心円型」属性の分布に多様な変化がみられた.(2)従来明瞭であった東南部低地のブルーカラー層と西北部高燥地のホワイトカラー層のセクトリアルな対比が,ブルーカラー層の大幅減少や専門技術管理職層の都心部集中などにより不明瞭になった.またブルーカラー層がホワイトカラー層に対比されるだけの社会集団としての意義を失った.(3)都心部の居住水準が大幅に向上し,都心部の居住地区としての意義が変質してきたことが把握された.以上の変化は,仙台市の都心機能の拡大を直接の要因としつつ,わが国産業の脱工業化・ソフト化や,少子化・高齢化・小家族化などの家族形態の構造的な変化を背景として生じているものと考察される.
  • 小口 千明, 八田 珠郎, 松倉 公憲
    1994 年 67 巻 11 号 p. 775-793
    発行日: 1994/11/01
    公開日: 2008/12/25
    ジャーナル フリー
    岩石の風化機構の解明を目的とし,風化による岩石物性の時間変化について調査した. 1.1ka, 2.6ka, 20ka, 40kaに噴出した4つの流紋岩質溶岩円頂丘が分布する神津島を調査地域とした.鉱物組成・化学組成などの予察的な分析によれば,溶岩円頂丘の形成当初の岩石物性は類似していた.また,採石場の露頭においては岩相の変化はほとんどなく,シュミットロックハンマー反発値も,地表からの深さに対応した変化を示さなかった.したがって,多孔質流紋岩は,厚く均一に風化する,いわゆる“deep weathering”の特徴をもつと考えられる.この解釈により,現在の岩石物性は各噴出年代からの経過時間における風化程度を示していると仮定できる.各溶岩円頂丘の露頭から採取した岩石試料を用いた種々の岩石物性の分析により,物性の時間変化は物性の種類により異なることが明らかになった。すなわち,化学的性質および比表面積は,最初の2万年間では徐々に, 2~4万年で急激に変化するのに対し,かさ密度,間隙率および力学的性質は,最初急激に,その後徐々に変化する.
  • 吉山 昭
    1994 年 67 巻 11 号 p. 794-802
    発行日: 1994/11/01
    公開日: 2008/12/25
    ジャーナル フリー
    In this study topographic measurements of channels and drainage basins were performed to clarify the quantitative relationships between channel slope and drainage basin topography, characterized by two distinct parameters, drainage area (A) and mean drainage height (H). The latter was defined as the mountain volume of a catchment divided by the former.
    Digital elevation data prepared by the Geographical Survey Institute of Japan were utilized for automated and nationwide measurement. Before calculating the drainage area and the mean drainage height at an arbitrary grid point of the digital elevation data, grid drainage networks composed of flow direction lines, which point to the lowest grid point among the eight neighbors, were made.
    The channel slope can be obtained as the fall of a flow direction line; however, it is not expected to show the actual channel slope because the grid interval is too short to estimate gradient. Thus the channel reach, composed of several steps in the flow direction lines, was defined according to the condition that in each reach the integer values of the logarithm of the associated drainage area are equal to each other. The base of the logarithm must be 2 for the consistent ordering of the channel reaches.
    The relationship among the drainage area (A), the mean drainage height (H), and the slope of the channel reach (I) was defined by the following equation:
    I=kHAm,
    where k and m are constants. The values of m were computed by least-square regression for 84 basins in Japan whose drainage areas were ranked between 1, 024 km2 and 2, 047 km2. The values of m ranged from -0.6 to -0.7 with very high correlation coefficients, and the average was -0.66. Although the investigated river basins have various climatic and geologic conditions, the deviations of m did not indicate any regional trends.
    Presuming m as -0.5 in the previous equation, the following equation:
    IH/√A,
    was also examined, where, β is a dimensionless constant. The variable H/-√A, which represents the drainage relief number, indicates the aspect ratio or relief ratio of the drainage basin. The average value of β derived from the 84 basins mentioned above was 0.38, and the standard deviation was 0.045. The constancy of β among various basins shows that the channel slope is more strongly regulated by relief characteristics than by other conditions such as climate and lithology.
  • 石崎 尚人
    1994 年 67 巻 11 号 p. 803-817
    発行日: 1994/11/01
    公開日: 2008/12/25
    ジャーナル フリー
    Many cities in Japan have only a few large public open spaces with woods, but they have many small patches with garden trees scattered in private land. Among various types of garden trees, tall tree is the most momentous amenity resource in urban areas and as an important item in composed townscapes.
    The aim of this study is to make clear the distribution and species component of preserved tall trees which have been planted in private land in the Ward area (23 wards) of Tokyo Metropolis, Japan's capital city.
    In this study the author used data on preserved trees in 20 wards (refer to Table 2) as an index for the degree of accumulation of these trees.
    The result of the data analysis can be summarized as follows:
    1. The 12, 224 tall trees located in 20 wards can be classified into 122 species.
    2. The density (n/km2) of preserved trees is generally high in wards located in upland and low in those located in lowlands (Fig. 2).
    3. The main component species, which account for over 1 % of all trees, are the following 11 species : Zelkova serrata, Ginkgo biloba, Castanopsis (main species is Castanopsis cupidata), Prunus (main spe-cies is Prunus X yedoensis), Pinus (main species are Pinus densiflora and Pinus thunbergii), Cinnamomum camphora, Quercus (main species is Quercus mysinaefolia), Cedrus deodara, Celtis sinensis, Aphananthe aspera, and Machilus (main species is Machilus thunbergii) (Table 2). Among these, Zelkova serrata, Ginkgo biloba, and Castanopsis occupy over 10% of the all trees, and are generally distributed in all 20 wards (Table 2).
    4. Exotic species include 45 species, which correspond to 40% of all 122 recorded species and to 25% of all trees. Seven of these, Zelkova serrata, Castanopsis, Pinus, Quercus, Celtis sinensis, Apha-nanthe aspera, and Machilus, are local species.
    5. The distribution patterns of these main component species can be divided into two types : widely distributed pattern (Zelkova serrata, Ginkgo biloba, Castanopsis, Cinnamomum camphora, Celtis sinensis, and Aphananthe aspera), and localized pattern (Prunus, Pinus, Quercus, Cedrus deodara, and Machilus) (Fig. 4). Among the former, the distribution patterns of Zelkova serrata, Ginkgo biloba, and Castanopsis are different in each high-density zone: Zelkova serrate is distributed in the outer city zone, especially the western part ; Ginkgo biloba in the inner area, and Castanopsis in the centralwestern part of the upland (Yamanote area). The latter type is divided into three patterns : 1) Prunus, Qercus, and Cedrus deodara occupy the upland, 2) Machilus occupy the lowland, 3) Pinus distribution is divided between a part of the upland and into a part of the lowland.
    6. From the viewpoint of species diversity of the preserved trees, the 20 studied wards are divided into two zones according to the values calculated by diversity indexes (Fig. 5). Eight wards-Suginami-ku, Nakano-ku, Toshima-ku, Shinjuku-ku, Shibuya-ku, Meguro-ku, Minato-ku, and Shinagawa-ku -show high rates, and they are located on a part of the upland area (bordering the Yamanote area and along the JR Chuo Rail Line). The remaining 12 wards have a low rate, and all of them except Katsushika-ku are divided into two sub-types: Zelkova serrata type and Ginkgo biloba type. The former are located in the outer city zone: Nerima-ku, Setagaya-ku, Itabashi-ku, Kita-ku, Adachi-ku, and Edogawa-ku; the latter -Bunkyo-ku, Arakawa-ku, Taito-ku, Sumida-ku, and Koto-ku-are in or near the Shitamachi area (Fig. 5, Table 2).
  • 1994 年 67 巻 11 号 p. 818-822,826
    発行日: 1994/11/01
    公開日: 2008/12/25
    ジャーナル フリー
  • 1994 年 67 巻 11 号 p. 825
    発行日: 1994年
    公開日: 2008/12/25
    ジャーナル フリー
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