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- All Subjects: urban planning
- Creators: Cai, Jianming
This study investigates the impact of urban form and landscaping type on the mid-afternoon microclimate in semi-arid Phoenix, Arizona. The goal is to find effective urban form and design strategies to ameliorate temperatures during the summer months. We simulated near-ground air temperatures for typical residential neighborhoods in Phoenix using the three-dimensional microclimate model ENVI-met. The model was validated using weather observations from the North Desert Village (NDV) landscape experiment, located on the Arizona State University's Polytechnic campus. The NDV is an ideal site to determine the model's input parameters, since it is a controlled environment recreating three prevailing residential landscape types in the Phoenix metropolitan area (mesic, oasis, and xeric).
After validation, we designed five neighborhoods with different urban forms that represent a realistic cross-section of typical residential neighborhoods in Phoenix. The scenarios follow the Local Climate Zone (LCZ) classification scheme after Stewart and Oke. We then combined the neighborhoods with three landscape designs and, using ENVI-met, simulated microclimate conditions for these neighborhoods for a typical summer day. Results were analyzed in terms of mid-afternoon air temperature distribution and variation, ventilation, surface temperatures, and shading. Findings show that advection is important for the distribution of within-design temperatures and that spatial differences in cooling are strongly related to solar radiation and local shading patterns. In mid-afternoon, dense urban forms can create local cool islands. Our approach suggests that the LCZ concept is useful for planning and design purposes.
To explore peri-urbanization in Dongxihu, this study first documents the metrics of ongoing peri-urbanization in the District from land use, economic, demographic and institutional perspectives. Causality is explored by relating peri-urban outcomes to drivers within the framework of research questions, namely: (i) What is driving peri-urban change in Dongxihu? (ii) Which drivers of peri-urbanization in the District are most important? (iii) How can Dong Xi Hu's peri-urbanization process and outcomes best be characterized? and (iv) What policy implications can be drawn from Dong Xi Hu's peri-urbanization experience?
The primary conclusion is that Dongxihu's peri-urbanization is primarily manufacturing driven, resembling previous first generation peri-urbanization on the coast more than the more diverse peri-urban outcomes now emerging in wealthy coastal metropolitan areas, e.g., Shanghai.
The results of this assessment will inform Beijing’s policy-makers regarding potential obstacles, pitfalls, or potential disruptions on the road to premier ‘World City’ status, and emphasize the need to undertake peremptory interventions and/or prepare contingency responses, as well as, inform stakeholders and decision-makers of critical and non-critical interventions recommended to achieve World City status by the year 2030.
In the case of Taiyuan, this industrial third-tier city of 4.2 million people. A majority of the newer residential services and high-end commercial areas are on the older, eastern side of the city. Since 2007, major urban investments have been made in developing the corridor that leads to the airport, including building a massive hospital, a new sports stadium, and "University City". The intention of the city officials is to encourage a new image of Taiyuan- one that is a tourist destination, one that has a high standard of living for residents. However, the consequences of these major developments might be immense, because of the required shift of community, residents and capital that would be required to sustain these new areas. Much of the new development lacks the reliable and frequent public transit of the more established downtown areas.
Do these investments in medical complexes, sports stadiums and massive shopping centers create new jobs that impact the income disparity, or do these new areas take years to fill, creating vacuums of investment that remove funding from areas with established communities? Can Taiyuan move successfully to a post-industrial economy with these government interventions, or is it too much too soon?
By examining demographic data from 2000, 2007, 2009, 2011, and 2013, research on sustainability assessments in Chinese cities (Lu Jia), and translated government publications detailing the urbanization efforts in Taiyuan, I will assess the results of the urbanization changes instituted by the new mayor, Geng Yanbo. My thesis will evaluate the success and failures of these policies and the implications for Taiyuan.
This study identifies flexibility and accountability as two important characteristics of the Chinese governance context, and traces how they affect stakeholder behavior and coalition formation, which in turn impacts policy implementation performance. The case study methodology triangulates analysis of government policy documents, secondary data, and the results of semi-structured key informant interviews.
Findings include: (i) The Chinese government has a very strong implementation capability to pass directives down and scale up, enabling rapid accomplishment of massive goals. It also has the capability to decide how the market should come into play, and to shape public opinion and ignore opposition; (ii) Interventions from the authoritarian government, given China’s vast economy and market, and the efficient top-down tiered bureaucratic system, risk distorting the market and the real policy goals during the implementation process; (iii) There tends to be an absence of bottom-up participation and feedback mechanisms; (iv) An effective self-correction mechanism, associated with flexibility and adaptability by a myriad of stakeholders often enables effective policy adjustment.
Policy implications include: (i) Policy implementation concerns need to be integrated into policy design; (ii) More thorough discussion of options is required during policy design; (iii) Better communication channels and instruments are needed to provide feedback from the bottom-up; (iv) On complex policy issues such as air pollution, pilot projects should be carried out before massive adoption of a policy.
This study investigates the impact of urban form and landscaping type on the mid-afternoon microclimate in semi-arid Phoenix, Arizona. The goal is to find effective urban form and design strategies to ameliorate temperatures during the summer months. We simulated near-ground air temperatures for typical residential neighborhoods in Phoenix using the three-dimensional microclimate model ENVI-met. The model was validated using weather observations from the North Desert Village (NDV) landscape experiment, located on the Arizona State University's Polytechnic campus. The NDV is an ideal site to determine the model's input parameters, since it is a controlled environment recreating three prevailing residential landscape types in the Phoenix metropolitan area (mesic, oasis, and xeric). After validation, we designed five neighborhoods with different urban forms that represent a realistic cross-section of typical residential neighborhoods in Phoenix. The scenarios follow the Local Climate Zone (LCZ) classification scheme after Stewart and Oke. We then combined the neighborhoods with three landscape designs and, using ENVI-met, simulated microclimate conditions for these neighborhoods for a typical summer day. Results were analyzed in terms of mid-afternoon air temperature distribution and variation, ventilation, surface temperatures, and shading. Findings show that advection is important for the distribution of within-design temperatures and that spatial differences in cooling are strongly related to solar radiation and local shading patterns. In mid-afternoon, dense urban forms can create local cool islands. Our approach suggests that the LCZ concept is useful for planning and design purposes.