仙台市の小売商圏がそのほぼ全域をおおっている宮城県,および仙台市の小売商圏よりその地域的広がりは狭いが,ほぼ同規模の商圏が隣接している岩手県北上地方において,買物依存率を変数とするdyadicfactor analysis法を用いて,小売商圏の重層性を分析し,小売業よりみた市町村の階層システムを考察した.その結果. 4レベルの商圏が検出された. 4レベルの商圏は相互に階層関係にあり,両地域内では仙台,石巻,気仙沼,一関,水沢,北上,花巻,盛岡の8都市をそれぞれの中心とする階層システムが形成されていることが明らかになった.特殊な場合にのみ出現する最低次レベルの商圏を除くと,仙台,石巻,気仙沼,一関,水沢の5つの階層システムは三層構造であり,他の3つの階層システムは二層構造である.また,各階層システムを構成している商圏レベルの数は,システムの中心都市の商圏規模には左右されないことが明らかになった.

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本稿では,大手不動産資本によるオフィス形成の特徴や役割を明らかにするため,オフィスビルの配置,テナントの特徴,都市形成への影響の3点について検討を行なった.
先発で東京都心部に大量の土地を所有する三菱地所は,丸の内に一点集中的にビルを配置させ,オフィス街を形成してきた.これに対し,三井不動産は所有地の少なさを超高層ビルによる点的開発で補い,オフィス空間の拡大を図った.そして両社とも,おのおののグループ企業の本社・支所の拠点を形成してきた.一方,後発の日本生命は,地方中核都市などに分散的にビルを配置させ,急成長で多事業所を必要とする企業に空間を提供した.また,森ビルは港区虎ノ門周辺で,戦前からの所有地を基盤に,住宅・商店と混在するかたちでビルを建設し,対事業所サービス関連企業を主なテナントとしてきた.
このように,系列,参入時期,土地所有によりオフィス空間の形成はさまざまであるが,大手不動産資本は,オフィスのより一層の集積を可能にし,あわせて都心形成を特徴的におしすすめてきたのである.

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Microclimatological conditions of Miscanthus sinensis stand in terms of plant succession were observed in summer (August 19_??_20) and autumn (October 30_??_31), 1982, in two different stands. One grows on convex topography (stand A) and the other on concave (stand B) in the observation area. Air temperature, specific humidity, soil temperature, solar radiation and soil moisture content were recorded hourly or at adequate intervals during the experimental periods.
Measurements were also made on plant height, floristic composition and productive structure of both Miscanthus sinensis stands.
Results are summarized as follows:
1. Soil moisture content in the stand B is greater than that in the stand A through-out the observed period.
2. Plant height and density are greater in the stand B than that in the stand A.
3. Solar radiation reaching to the ground surface in the stand A is greater than that in the stand B.
4. Maximum air temperature and the diurnal range of air temperature near the ground surface (6, 15 and 26cm height) are greater in the stand A than that in the stand B. Minimum soil temperature in the stand A is slightly higher than that in the stand B.

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The angle of earth-slide slope of Higashiyama Hill is investigated from the dynamic viewpoint: the earth-slide actually occurred in June, 1976. The slide surface (plane) of this earth-slide is located inside the weathered debris of gabbro (Fig. 1). The slope section indicates that this earth-slide belongs to the “slab-slide”. The average rate of the initial sliding is estimated at about 50 mm/day. Field observations performed in July to October, 1977, approximately one year after the event indicate that groundwater table continues to rise in approximately parallel with the slide surface following to the rainfall, hence the rate of slide-movement increases (Fig. 2).
Application of the Infinite Slope analysis would be reasonable for the present case. The equation given by Skempton and DeL.ory (1957, p. 309) was modified:
F_s=c'+[(γ₁Z₁+γ₂Z₂+γ₃Z₃)-mγ_wZ]cos²βtanφ'/(γ₁Z₁+γ₂Z₂+γ₃Z₃)sinβcosβ
where γ and Z denote respectively the saturated unit weight of the soil and the thickness of the soil, with suffixes 1, 2, and 3 indicating respectively volcanic ash soil, pumice, and earth-slide soil, F_S is the factor of safety, γ_w is the unit weight of the water, β is the slope angle, c' and φ' are the cohesion and the angle of shearing resistance of earth-slide soils, respectively, and m is the fraction of Z such that mZ is the vertical height of the ground-water table above the slide surface.
Drained direct shear tests were performed on the intact earth-slide soils using a 6-cm diameter shear box adapted for reversals. The tests were conducted under a strain control of 0.03_??_0.045 mm/min. Figure 3 shows the one example of stress-strain relations. The strength envelops in Fig. 4 give the following data: c'_p=0.169 kgf/cm², φ'_p=27.8° for peak strength, and c'_r=0.122 kgf/cm², φ'_r=10.6° for residual strength.
Substituting 1) these strength parameters and 2) Z₁=2.8 m, Z₂=0.5 m, Z₃=3.1 m, Z=6.4 m, γ₁=1.74 gf/cm³, γ₂=1.20 gf/cm³, and γ³=1.79 gf/cm³ into equation (1), the relationships between F_S and β were obtained under various m-values (m=0, full drained; m=1.0, water table to the slope surface) (Fig. 5). At the actual slopes, as shown in Fig. 2, the groundwater table fluctuated between the half depth of slide mass (m=0.5) and the slope surface (m=1.0).
The average angle of pre-slide slope is estimated to be about 13.9°. The factor of safety calculated using this slope angle and the peak strength and assuming m=1.0 is 1.55 (Fig. 5). Thus, the pre-slide slope might be stable under this condition. On the other hand, at the critical stable under a condition that the m-values fluctuate between 0.5 and 1.0, the calculated residual factor ranges from 0.72 to 1.01. This suggests that the soil strength had reduced nearly to the residual strength when the initial failure occurred.
The slope angle of one year after the initial slide is estimated at about 11.3°. The factor of safety calculated using this slope angle and the residual strength and assuming m=0.5 to 1.0 lies in a range of 1.24_??_0.97 (Fig. 5).

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