Since the late 1980s, concerned with arguments about the arrival of the “post-fordist” epoch, studies of agglomeration blossomed in the West. In the 1980s, most studies showed that the advantages of agglomeration are external economies, which provide static efficiency with economic actors. In the 1990s, in contrast, the dynamic aspect of agglomeration from the viewpoint of innovation and learning was widely discussed.
The latter studies had a common understanding of various relationships within the regional effects of dynamic agglomerations. This paper considers such relationships as the “assets” of economic activity and define the contents of relational assets as the function and nature of “convention.” (Convention functions as a device that coordinates the actions of economic actors.)
This paper, based on Storper and Salais's framework of “worlds of production” according to the notion of convention, examines the source of dynamism of the Kojima production area in the garment industry. The result clearly shows that the notion of convention and the framework of “worlds of production” are very useful for the analysis of reality.
In the Kojima production area, the relationships and “worlds of production” are complex at first sight. However, through this framework we can classify the “worlds of Production” of Kojima into three types: the “industrial world” and “market world”; the “market world” and “interpersonal world”; and finally the “industrial world.” Moreover, by considering the dimensions of interpretation and representation that constrain the actors' principles of action, this approach can demonstrate the dynamics of the Kojima production area. In Kojima, the three worlds of production are constructed around the “market world.” These worlds have appropriate conventions that coordinate the actors' behavior. Based on such conventions, local relationships become assets, which consequently support the success of the region. Using these frameworks, we can deal with the diversity of the real world and show why certain regions succeed economically.

View full abstract

The flood control forest is a traditional river control measure that has been reevaluated as an effective and flood-tolerant method over the last decade. The flood control forest is important not only as a flood control measure or part of the local ecosystem but also as an educational site for disaster prevention awareness and environmental perception for the inhabitants of a frequently flooded region. The new River Law enacted in 1997 upholds the flood control forest, and its function of flood water control and since then this type of forest has been studied rather intensively. Ecological studies on riparian forests, on the other hand, focus on the relationship between forest dynamics and riverbed disturbance with sediment transport. To understand the dynamics of artificially formed flood control forests in local ecosystems, studies from both functional and ecological viewpoints are necessary. The author investigated the sediment control function of the flood control forest and examined its role in the development of riverbed landforms in the middle reaches of the Kuji River, Ibaraki Prefecture, central Japan, where patches of typical flood control forest are still well maintained.
The study area of the flood control forest can be classified into two types based on aerial photograph interpretations and field observations: 1) flood control forest located in front of a terrace scarp or artificial embankment; and 2) flood control forest located on natural levees. The first type has the function of protecting the artificial banks and terrace scarps from erosion by flood water. This f unction was confirmed in the literature and in interviews with local inhabitants. The grain size analysis of sediments of the natural levees with flood control forests, confirms that the sediment includes both the riverbed material and suspended sand. This indicates that the flood control forest screened the bed load by increasing the surface roughness of the riverbed, and that by letting the flood water remain in the forest for a while allows suspended sediments on the forest floor to be trapped. The structure of the natural levees shows the cumulative deposition of sediments of past floods.
Flood control forests promote the development of natural levees by trapping the sediments on the forest floor through their screening function. The flood control forest can be appreciated as a “self-growing river control structure” that improves the flood control effect to harmonize with the geomorphic processes. The flood control forest also needs the social consciousness of the inhabitants and managers. The flood control forest should be evaluated in greater depth.

View full abstract

The present study attempted to examine the formative process of beach cusps on a shingle beach through field and laboratory experiments. Temporal changes in foreshore morphology and swash pattern were continuously monitored using a video camera suspended over an artificially flattened section at a pocket beach of Banba-ura at the tip of the Manazuru Peninsula in Sagami Bay. In the laboratory, swash-zone morphological changes were investigated on a uniformly inclined model beach in a wave tank. Cusps developed well in both field and laboratory experiments. Cusp spacings were 2.2-2.5m in the field and 29-35cm in the laboratory. The Froude similarity law indicates that the laboratory cusp spacing corresponds to the spacing of 7.7-9.5m in the field. Although this value is much larger than the cusp spacing observed in the field experiment, they were still on the same order of magnitude; and therefore, the results of field and laboratory experiments are considered comparable. Cusp formation was triggered by the presence of a small depression or a mound associated with an obstacle such as boulders in the field and the side wall of the tank in the laboratory. A series of cusps gradually and successively developed alongshore from the location of obstacles, simultaneously changing an incipient two-dimensional swash pattern into three-dimensional features. Along-shore migration of the interaction between topography and flow structure in the swash zone appears to promote the development of beach cusps.

View full abstract

This paper discusses the period of slope instability and the formative processes of block deposits on the Kobugahara Plateau, northern part of the Ashio Mountains. The plateau is mostly underlain by granodiorite and characterized by many core stones and tors derived from the deep weathering profile of the bedrock. Some block deposition features, similar to so-called block streams, also occur on the plateau. Many water streams flow through the block deposition features. It suggest that transportation of fine weathered materials by running water and accumulation of core stones as lag deposits were important formation processes of the features. The topographic characteristics of the block deposition features, however, indicate that slow mass movement also played an important role in their formation. Three types of finer slope deposits, gully-fill colluvium, upper fine deposits, and lower fine deposits, also occur as surficial deposits on the plateau. The upper fine deposits are composed of nonbedded humic soil and silt layers. The lower fine deposits include granodiorite blocks, fragmented weathered rocks, Ag-KP pumice (ca. 45-50 ka), and Nt-I scoria (ca. 14-15 ka). The blocks, rock fragments, and Ag-KP grains are randomly scattered in a brown silty matrix, while Nt-I grains occur only in the upper part of the deposits. The gully-fill colluvium, composed of silt and scattered granodiorite blocks, has infilled gullies entrenched in the lower fine deposits. The broad occurrence of the lower fine deposits and the intercalated tephras point to the period of slope instability between ca. 50 ka and 15 ka. The facies and distribution of the lower fine deposits as well as their age suggest that they were formed by slow periglacial mass movement. Deposits forming the block deposition features are unconformably underlain by the lower fine deposits, suggesting that the block deposition features formed after the period of widespread slope instability. A relatively wet and cold climate around the Pleistocene-Holocene transition may have facilitated the formation of the block deposition features due to both slow mass movement and the fluvial transportation of fine materials.

View full abstract