The volcanic mudflow occures as an accident in the process of the landform formation. It builts up such unusual landforms as the mudflow hills and river terraces caused by the volcanic activity. In Japan there are many active volcanoes having the mudflow deposits on their mountain-foots. Some of the deposits can be transported to the alluvial land near the volcanoes. But there are few studies adout the geomorphological changes in the alluvial land due to the volcanic mudflow. The paper deals with the case that the volcanic mudfiow directly gave effect to the valley plain alone. It aims at clarifing how the volcanic mudflow has influences on the formation of the alluvial land-forms directly and indirectly. It is well-known that the Bandai Volcano broke away by one-third due to the steam explosion on the 15th of July, 1888 and that the huge dry mudflow depo~fits filled up the valleys in the upper reaches of the Nagase River. As the result of it, many mudflow hills and lakes were formed. The area studied can be divided into two parts: the valley pla, in and the alluvial plain of the Nagase Rivers. The Nagase River originates in the north foot of the Bandai Volcano and flows into Inawashiro Lake. When the mudflow deposits filled up the valley, many mudflow hills were formed on the valley plain. The average height of the mudflow hill reliefs is about 30 metres at the neck of the valley near Tsuchiyu-Dani. At the lower reach of the neck the height of the mudflow hills abruptly become small. It seems that the mudfiow deposits have a thickness of more than 40 metres in the valley. The maximum diameter of the boulders found in the mudflow are 500 to 700 centi metres at the lower reach of the neck. Since the time when the valley of the Nagase River was filled up by the mudfiow deposits, fioods had occured very frequently until the construction of the dams in 1916 in the alluvial plain of the Nagase River. The small natural levees were formed along the river course every flood. The location of the Nagase River mouth advanced about 500 metres offshore and it made the delta temporarily large. As the result of the construc-tion of the dams, the river mouth has today gone back to its original location. Ultimately the Ura-Bandai dry mudflow caused a great direct geomorphological influ-ence, with the formation of the mudfiow hills, upon the valley plain of the Nagase River. The indirect effects of the mudflow for the alluvial plain of the lower reach of the Nagase River were a slight expansion of the delta and the formation of the small natural levees. But the effects were not so great as estimated. The reasons why the landforms of the alluvial plain were little changed may safely be put as follows : l. The m,udflow was dammed up by the neck of the valley. 2. The foreset slope of the Nagase delta was so steep that the mudflow deposits did not advance the delta offshore. 3. The water volume of the Nagase river has been controled by the dams and waterways since 1916.
The purpose of this study is to consider the regional structure of Hiroshima City from a viewpoint of the intra-urban location pattern of the establishments. The old urban area in Hiroshima City has a population of approximately 550, OOO and an area of 48 square kilometers, where most of the urban functions of the present urban area are concentrated. That is to say, this area is the center of economic, social, cultural and governmental activities in Hiroshirna City. The study was based on a data matrix consisting of 70 variables by using the classified telephone directory and 200 areal units, and this data matrix is applied to a multivariate analysis. The main results of this study are summarized as follows : (1) Factor analysis is applied to a locational specialization tendency. Nine functional factors could be interpreted. They are namely, ( I ) a financial and administrative function factor (H) a convenience good and service function factor (IID a manufacturing and building function factor (IV) a shopping good retailing and wholesaling function factor (V) a textile wholesaling and hotel furrction factor (VD a perishable foodstuff retailing and wholesaling function factor (Vrr) a religious and educational function factor (VED a shipbuilding and warehouse function factor (lX) an eating and drinking function factor Therefore, it is pointed out that the establishments in the old urban section of Hiroshirna City are locational-specialized in these nine functional groups. Especially ( I ), (IV), (~O in these functional groups are the main elements which make up the intra-urban location pattern as shown in the high level of explained variance. (2) From the distributional tendency of the factor score, it is suggested that three functions consisting of financial and administrative, shopping good retailing, eating and drinking are concentrated in the city centre, morever that these three functions have formed clearly functional differenciation areas. The manufacturing function has been concentrated on the old urban fringe where traditional minor factories are characteristic, and on the seaside area where the shipbuilding industry and automotive industry with modern large factories are located. (3) According to the relationship between the distribution of each factor score and the distance from civic center, the location pattern of the nine functions is set up the concentric model. This model is more fully developed by considering the distribution of the dominant district of each function, and it suggests the location pattern model as shown in Fig. 4. (4) By the application of cluster analysis to the factor score, five groups of functional districts can be identified. They are as follows : (A) a no-dominant function district group (B) a manufacturing and building function district group (C) a no-dominant manufacturing and building function district group (D) a financial and administrative function district group (E) a manufacturing and building function district group (E is more dominant than B) As (~), (C), (D) in the five groups have respectively many constituent districts and variations, their groups can be divided into several subgroups. Futhermore, it is pointed out from the whole tendency of the distribution of grouping districts that the nearer the district is to the city centre, the more dominant the functional aeral diffe-rentiation is. The above stated is the l~esult of this study which was to try to clarify one side of the intra-urban regional structure, that is, the location pattern of the establishments. As a next reseach step it will be my task to attempt an analysis of the location pattern of the residential function w'nich is a very important constituent element in the urban structure. Morever, in order to grasp the establishment location pattern from a dynamic viewpoint, the formative process and factors of the location pattern must be made clear, too.
The centrifugal expansion of housing estates causes the population to straggle, and rernarkable changes are detected in the aspects of shopping streets in the traditional 10cal centers. It is natural that shopping streets should be formed where some shopping streets have been existing in some form or other since the olden times. But there is an excep-tion that a shopping street declines when its locational condition has become remarkably worse through housing development. On the assumption that the traffilc system has been the geographical cause of the 10cational movement of the shopping street in Kabe-cho, where suburbanization is in an advanced stage, the writer compared the new shopping street with the old one, and investigated into the period of the movement and the change in respect of appearance and function. The main findings are summarized as follows: (1) The new shopping street was formed on the paddy field zone through the opening of the bypass in 1964 and the subsequent change of the bus route the next year. The street mentioned above has two functions: one for shopping and the other for busi-ness transaction. At the early stage of the formation of the new shopping street many stores were opened, that is, stores removed from the old street, and new branches were opened with the local capital. But with the gradual increase of the capital inflow from Hiroshima City, the shop-ping street dashed into a period of cubic development as the result of the expansion of big stores to this area after 1971. Through such process of development this street has established its position as the central shopping street in Kabe-cho. (2) The old shopping street formerly developed into the central shopping street sup-ported by the old tradititon, but the formation and development of the new one owing to the expansion of suburban area exercised a great infiuence on the old one. For exarnple, the numbr of new stores has increased, while that of changed and closed stores has slso increased, and at the same time some stores removed to the new shopping street or they opened their branches. Thus the old shopping street was transformed to a high level shopping street, but recently its locational condition relatively depreciated through the change of the bus route and the development of new street. The result was that some stores were compelled to change their business or rernove their location. As for the shopping street near the station, the same transformation is perceived. (3) The trade area of Kabe is embraced in that of Hiroshima, and is the largest among those in the northern part of Hiroshima. Nowadays the consumers recognize the new shopping street as the main one in the Kabe-cho. (4) In Kabe and its neighboring area, where people depend chi.efly on cars of transpor-tation. In the new shopping streets some parking places are established and it is very convenient for the car drivers who are inhabited in Kabe and its neighboring area. On the contrary, in the old one, in spite of the availability of the railway, the number of people ~vho use it is rather small. Moreover, the old one is fL111 of troubles, because it cannot confonTl itself to the change of times. (5) Kabe-cho has not still lost its part as a local center in the northern region of Hiroshima. The fonnation of a new street has quickened the rejuvenation at the town and it has also helped the modernization of the area to promote further. (6) The gap in function and landscape between the new one and the old one had widened acceleratively because of the failul~e of modernization of the old shopping street and the inability of its storekeepers to awaken themselves to the necessity of moderniza-tion.