The 2004 Sumatra-Andaman earthquake generated remarkable uplift and subsidence at different locations in the Andaman and Nicobar Islands. Previous studies revealed that a southeast tilting phenomenon, i. e., northwest uplift and southeast subsidence, occurred around the Andaman Islands. At more than a dozen points, the amount of subsidence was measured using GPS, but unfortunately there were few GPS sites in the uplifted areas, and it was almost impossible to conduct ground surveys or use photogrammetry owing to the strict control enforced by the Indian government on access to these locations.
The purposes of this study were to determine the amount of coseismic uplift associated with the earthquake at the northwesternmost part of North Andaman Island, Indian Ocean, and to discuss why the largest coseismic uplift occurred there, considering the submarine topography and free-air gravity anomaly in the area. Reef Island, located off the northwesternmost part of North Andaman Island, was chosen as the study area for lack of coseismic movement data.
Around the northwestern part of North Andaman Island, including Reef Island, the amount of uplift seemed to have decreased within several months after the earthquake due to postseismic creep. In this paper, the displacement on Reef Island was measured using satellite imagery obtained immediately after the earthquake. To measure the amount of uplift, first a digital surface model (DSM) was generated using IKONOS and QuickBird single images. Next, the shoreline change, as determined by comparing the preearthquake with the postearthquake images, was interpreted using GIS as a change in the ground height.
As a result, it was found that Reef Island was uplifted by 2.2m shortly after the earthquake. With this method, the standard deviation was 0.8m; however, it is clear that the amount of uplift on Reef Island was not less than 2m, as evidenced by the exposed coral reef margin in the satellite imagery.
Reef Island is the closest to the Sunda Trench. From free-air gravity anomaly data, the northwesternmost part of North Andaman Island is characterized as a high-anomaly area, in comparison with the surroundings. Therefore these tectonic characteristics are expected to be related to the fact that the largest uplift occurred there.
With the use of the high-resolution satellite imagery to measure ground level changes, it was possible to perform a geomorphologic analysis of the region, where the interferometric synthetic aperture radar technique was not applicable due to its theoretical limitations, e. g., its inability to capture large deformations in the ground surface. In the near future, with the increasing accuracy of satellite data, research on the application of satellite data to geomorphology may lead to the development of a much broader range of potential applications.

View full abstract

This paper clarifies the need of the elderly for sources of support and investigates the complementary relationship between sources of support and regional welfare activities with resident participation in hilly and mountainous areas using Miyoshi, Hiroshima Prefecture, as a case study.
Many elderly living in hilly and mountainous areas live separately from their children, and so find it difficult to obtain support from family members. It became clear that there was a growing need for support of the elderly by neighbors to supplement support from children. There are differences from one settlement to the next, however, in terms of support needs involving neighbors, and the decreasing numbers and increasing age of neighbors has raised concerns that the needs of the elderly will not be met.
Regional welfare activities with resident participation, which have gained attention as a means of compensating for this “hollowing out” of support sources, are similar in content to the support that elderly have come to expect from neighbors. Regional welfare activities in Miyoshi are divided into “visiting type” and “commuting type, ” and the content and frequency of support differ depending on the systems of operation and the scope of the area targeted for activities. Visiting-type activities are conducted within a given “district, ” and involve the provision of support closely tied into the daily lifestyles of the elderly. One problem with this type of support is that it cannot always be provided when it is most needed. Commuting-type activities, on the other hand, are conducted mainly within a given settlement and so contribute to the reconstruction of social relations that have been subject to hollowing out. As part of these activities, the participants visit the homes of the elderly on a rotating basis. These activities, however, can only act as a partial supplement to the burden of support that had been borne by neighbors and family, and this role has its limitations.
As settlements approach their limits, an important issue will be putting in place sources of support that are closely linked to the daily lifestyles of the elderly.

View full abstract

Recent research trends on the global urban system, their problems, and the directions of future research are described. During the past decade, research on the global urban system has been promoted mainly by the Globalization and World Cities (GaWC)-Study Group & Network. Research with various theoretical backgrounds has made an issue of two aspects, the “global cities-global cities” relationship and the “global cities-territorial states” relationship, and has intended to show the global urban system as a different metageographical image of the world. Mainly using data from global service firms as an indicator, the GaWC has concretely drawn a figure of the global urban system. It has developed a comprehensive database of the office locations of global service firms and developed an “interlocking network model” to calculate interurban connectivity on the basis of a spatial interaction model. However, some problems can be pointed out. The organizational form assumed in the model is ambiguous; it could show either a hierarchical structure or network organization. Also, the validity of applying the model to other types of organizations, especially nongovernmental organizations (NGOs), has not been adequately considered. To introduce an explicitly organizational theory viewpoint into global urban system research and to conduct further study focusing on international NGOs not as an analogy of global service firms but as alternative global actors organizing another type of global space of flows are suggested.

View full abstract

Japan is steadily implementing approaches to establish a “material-cycle society, ” and an increasing number of municipalities are showing interest in introducing waste composting as one way to manage waste produced by households. At the same time, however, a number of municipalities that introduced garbage composting during the 1950s and 1960s have ended it. The purpose of this paper is to determine the factors causing those municipalities to halt their composting operations and also to examine the requirements for composting to become more viable.
Data were gathered through questionnaires and telephone interviews in 58 municipalities across the nation. It was determined that 11 had discontinued their composting operations and 47 were currently continuing them. Among the municipalities were the town of Tahara in Aichi Prefecture, which has stopped composting, and the town of Usuda in Nagano Prefecture, which is continuing it. These towns were chosen for on-site interviews.
The results can be summarized as follows. Decrepit facilities and/or mechanical failures in their composting plants provided a rationale for some municipalities to discontinue their programs. However, insufficient demand for compost was found to be the primary factor in termination. The low demand for compost was determined by its relatively low quality. There were several reasons for the low quality of compost products. First, there was insufficient and inaccurate sorting of waste at home, often resulting in nonorganic materials being included among the compost. Second, the compost products obtained through this system were often inconsistent in their quality because the waste components and resultant compost composition often fluctuated from day to day.
In conclusion, this paper suggests that there is an urgent need to devise measures to improve and maintain the quality of compost products so that municipal composting projects will be more viable and beneficial in the future.

View full abstract