本稿は,都心部の形成過程を通じ,最近の日本の都市で急速に進んでいる立体化について,とくに中高層建造物を中心に考察したものである.その結果,都市の機能分化は,従来の平面的機能分化以外に,その内部において立体的な機能分化を内包していることが判明した.すなわち,都心部では,物品販売・社交娯楽機能は地下1階～地上2階を中心に立地し,地下街とも有機的に結合している.地下2階以下は,主に駐車場や倉庫にあてられ,高層部分は業務・居住厚生機能の利用が多い.また,地下鉄など交通機関の立体化は,高層建造物の増加と関連が深く,さらに地下街も地下鉄や高層建造物の地下階の建設にともなって誕生した場合が多い.都心部の立体化は,これらのコンプレックスとして把握されねぽならないと考えるが,ここではとくに重点を中高層建造物において考察し,都心研究における立体的視点の重要性を示した.

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本稿の目的は,名古屋とその隣接地域における1957年のアジアかぜの流行を,モンテカルロ法を用いて,空間的拡散過程の観点から分析することにある. (1) ランダム・プロセス・モデル, (2) 通勤,通学者数から拡散確率圏を設定したモデルI, (3) モデルIに密度効果をくみこんだモデルIIからの模擬発生パターンを,現実の発生パターンと比較した結果,主としてモデルIからは,距離と都市規模が,更に,モデルIIからは,密度が,アジアかぜの拡散を規定していることがわかった.
しかし,現実の発生パターンを完全に説明するためには, (1) 通勤,通学者数を用いた確率圏の再考, (2) 人口規模別のコンタクト発生回数の検討, (3) 境界効果の設定, (4) 感受性に関係する変数の検出とモデルへのくみこみがなされる必要があると思われる.

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In this report the author intends to present one of the case studies on the geomorphic development of the Uetsu folded zone—the western half of Northeast Japan, where crustal movements have been active since the early Miocene and the folded Neogene strata are widely distributed. The area surveyed is located at a marginal part of the depositional basin of the Uonuma group upper Pliocene_??_lower Pleistocene which is composed of littoral and fluvial deposits. Landforms of this area are therefore supposed to have been developed throughout the Quaternary period under the distinctive influences of crustal movements.
After the deposition of the Uonuma group the folded structures were developed in some extent. Then a rather large fan was formed over the area covering two drainage basins of the Igarashi River and the Kariyada River. This is concluded from the distribution of the fanglomerate (Odaira formation) and the fact that the gravels transported by the Kariyada River are contained among the fanglomerate now located in the drainage basin of the Igarashi River. The Odaira formation is for the most part 20_??_30m in thickness and is underlain by the folded Uonuma group or the older strata. The summit level of the hills where the Odaira formation is distributed indicates the tectonically deformed fan surface (Fig. 3).
After the deposition of the Odaira formation the area concerned has kept upheaving and the main rivers have eroded by 50_??_200m downward. Many levels of terraces were formed during the dissection. They are classified into 6 levels (Ig-I_??_Ig-IV) as shown in Fig. 2. Most of these terraces are strath terraces, but some exceptions can be found. Fig. 4 shows longitudinal profiles of the terrace surfaces along the Igarashi River. It is clearly shown that the terrace surfaces converge toward a syncline between Ogibori and Sasaoka (A). The terrace deposits are thicker near the syncline than at the other localities. This indicates that the crustal movement which is recognized from the structure of strata older than the Odaira formation is of the same tendency as what is recognized from the deformation of terrace surfaces. It is also shown in Fig. 4 that terrace surfaces have been deformed by faults or flexures near Shimoppara (B, C), but this is not geologically confirmed.

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It was noted about some rivers in Japan that a valley in the upper reach of a river has a more gentle slope than has an alluvial fan in the lower reach. A simple possible hypothesis was provided for explanation by the authors. The gentle slope in the upper reach may be due to narrow width of flood water restricted by valley walls (Fig. 1).
The slope of a “flood plain” and water surface, width of water surface and velocity of flow under equilibrium condition were studied experimentally by use of a laboratory flume. Uniform and noncohensive sand, O.5_??_1.0mm in diameter was used for the experiment. The amount of sand supply and water discharge were kept constant during the operation. Six runs were carried out for different flume widths. Introduction of the water discharge and sand supply was accompanied by deposition until an equilibrium channel and a “flood plain” were established. By definition a stable equilibrium existed when the ratio of sand discharge to sand supply became to 1.0 averaged for sufficiently long time.
The flume width determined the slope of running water when the flume was narrow. When the flume was sufficiently wide as compared with water discharge, the steeper “flood plain” appeared in the flume. In the latter case, the slope of the “flood plain” and running water was determined mainly by discharge, independently of flume width (Fig. 2). It is thus inferred that there is a critical value of flume width, beyond which the slope is determined only by discharge. This value is mainly a function of discharge. The result obtained by the experiment (Table 1, Fig. 2) seems to support the above hypothesis on the slope of river bed.

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