Asian City Planning for a Sustainable Urban Society

This special issue is one of the outputs of the 9th International Symposium on City Planning and Environment Management in Asian Countries held on 11–13 January in 2014 at Horuto Hall OITA, Japan. Currently, Asia accounts for 40% of world׳s urban population, which will increase to 56% by 2030. Urbanization is one of the biggest issues in Asian countries. On the other hand, in the economic development countries such as Japan and South Korea, the aging problem has also emerged. In order to achieve the sustainable urban society, it is increasingly necessary to find urban design innovations and appropriate research methods and tools.

At present, the planning for the conservation or development of Japanese traditional crafts is based on administrative districts or water catchment areas. However, the conservation of Japanese traditions relies not only on the access to relevant natural resources but also on artisans׳ ability to manufacture crafts in specific environments. The perspectives of artisans on their work environments have a significant influence on traditional crafts. The first paper “Community spaces in the minds of traditional craftsmen in a pottery village in Japan” aimed to investigate the changes in natural resource use in a village recognized for Koishiwara-yaki-style pottery. The authors employed a questionnaire and conducted interview surveys to collect data on the perceptions of the artisans working in the villages. The main findings were as follows: 1) The area commonly regarded by the artisans as their place for pottery was identified. The identification of areas that are significant to local tradition can serve as a vital contribution to spatial planning; 2) The birthplace of the local ceramics tradition in a local water catchment area was regarded as critically important in the preservation of the traditions of the village; 3) Several potters emphasized the value of their work environment to administrative support because of the historical connection between the place and their traditions. Highlighting this connection can attract historical and cultural tourism to this area (Kota M., Sampei Y., Tadashi U., 2015).

Japan has one of the highest earthquake risks of any country in the world. The country has already experienced large-scale earthquakes, such as the Kanto Earthquake in 1923, Hanshin/Awaji Earthquake in 1995, and Tohoku Earthquake in 2011. Thus, there is an urgent need to increase disaster preparation and planning efforts to enhance the safety of those who may otherwise become victims of urban earthquake disasters. A large number of densely built-up areas that are extremely vulnerable to earthquakes (approximately 20,000 ha) still remain in Japan, and the implementation of corrective measures in these areas has been very slow. Making draft improvement plans through citizen– administration partnerships are indispensable to promote improvements. The planning support tools are proposed in the second paper “A support tool incorporating a district disaster mitigation performance evaluation method for the examination of improvement plans in built-up areas” to support a consensus-building process during the creation of draft improvement plans. The authors developed a disaster mitigation performance evaluation method (DMPEM) for built-up areas at the district level and incorporate this method into a disaster mitigation support Web-GIS. However, DMPEM requires lengthy calculation time because it uses the probabilistic Monte Carlo computation method. Using this tool in real-time planning is therefore difficult. In this study, the authors first developed a system that reduces the calculation time required by DMPEM. Second, the support tool is used to make draft plans through citizen– administration partnerships in districts where residents are conducting various disaster mitigation activities. Finally, they investigate the usefulness of the tool for consensus building through the promotion of lively discussions among residents and clarify the issues associated with practical use of the tool (Kazuki K., Akira O., Katsumi T. 2015).

The third paper “Development of a smart city planning support tool using the cooperative method” aimed to develop a support tool for the construction of a smart city using renewable energy while facilitating consensus-building efforts among residents using the method for a cooperative housing development. The authors organized the supporting methods for the construction of residential area using the cooperative method, and developed supporting tools that interface the computer with these methods. They examined the support techniques for the construction of a residential area using renewable energy technology by analyzing Japanese cases of a smart city. Moreover, they developed a support tool for the construction of a smart city on a trial basis, and integrated the smart city construction tools and the cooperative housing construction support tool. This tool has a 3D modeling system that helps residents to easily understand the space image as a result of the examination. They also developed a professional supporting tool that residents can consider for cost-effectiveness in renewable energy and its environmental load reduction rate for the planning of a smart city. The results of the study are as follows: 1) The support tool is considered a useful tool to examine the project evaluation for consensus building among participants during discussion and planning in a workshop. For example, it can examine the innovation of a renewable energy, such as a solar panel service and HEMS; 2) Through the use of a 3D model, the support tool can provide the space image after construction and examine the design plan in a residential area, such as the façade of a house and plants in a residential area; 3) By integrating these contents, the support tool can confirm the space image after construction and project evaluation at the same time(Takeshi K. and Shinji I., 2015).

Many cities organize cultural festivals to promote their distinctiveness, boost the local economy, and enhance quality of life. However, urban spaces are packed with visitors on festival days, thus affecting accessibility to pedestrian spaces. The fourth paper “Quantifying the relationship between visitor satisfaction and perceived accessibility to pedestrian spaces on festival days” examined visitor satisfaction with accessibility to pedestrian spaces during special events such as festivals. The authors particularly focused on the Hakata Dontaku festival, which is celebrated in Fukuoka, Japan. We studied three main elements that affect pedestrian satisfaction and perceived accessibility through walking, namely, safety, mobility, and amenities. They first analyzed previous studies and employed analytical hierarchy process to setup indicators for satisfaction measurement. Second, they determined visitor satisfaction through a survey questionnaire, which was conducted during the Hakata Dontaku festival. Third, we assessed the normality of the data set that was obtained from the questionnaire. Finally, they applied structural equation modeling. Results showed that the proposed model was a good fit, as indicated by the goodness of fit test, and the majority of indicators loaded significant values that supported their constructs. Satisfaction with amenities was found to be the most statistically significant variable that influences visitors׳ perceived accessibility during the Hakata Dontaku festival (Andini R. P., Shichen Z., Xiaoyan M., 2015).

The final paper “Characteristics of road network forms in historic districts of Japan” focused on the well-preserved road network forms of historic districts and analyzed the road spaces of 16 historic districts in Japan in terms of circularity, accessibility, and indirection based on graph theory. This study aimed to systematically clarify the spatial characteristics of the historic road spaces in districts with different formation backgrounds and their corresponding types. This research also endeavored to quantitatively describe the effect of road network formation on spatial characteristics. The main conclusions are presented as follows: 1) In traditional villages dominated by agriculture and fishery and are dependent on natural conditions, narrow streets that are less than 4m wide serve as auxiliary road systems to strengthen the overall connection of the road network. In a road network that functions as traffic connections to external communities and consists of roads that are more than 4m wide, narrow streets that are less than 4m wide further subdivide the internal grid of the districts; as a result of the highly elevated road density, the road form becomes dense and complex. Nonetheless, the narrow streets improve the circularity, accessibility, and indirection of the overall road spaces; 2) In settlements of port and commercial towns formed for port trade and commercial production purposes, the main frame of the road network is composed of roads that are over 4m wide. This network displays a complete overall form as well as ideal circularity, accessibility, and indirection. The roads that are less than 4m wide merely serve as subsidiary spaces; they further dividing some roads in local areas and exert little effect on the spatial characteristics of the overall road network; 3) Due to a historical isolated spatial mode, the districts in “Jinai-cho” towns emphasize inward traffic connection. The overall road network in such areas is jointly composed of horizontal roads that are more than 4m wide and vertical roads that are less than 4m wide. The removal of any of these portions renders the road network form incomplete and deteriorates road network circularity, accessibility, and indirection. The overall road network tends to take the grid form; thus, the circularity of this district type is higher than that of the remaining historic districts (Ze L., and Shichen Z., 2015).

Finally, we would like to express our sincere gratitude to the researchers who joined the symposium and submitted their works to “Frontiers of Architectural Research”. We would also like to express our sincere gratitude to the reviewers who gave us their most generous support on reading and commenting on the papers. We hope all our efforts would contribute to a more sustainable world.