CN 11-5366/S     ISSN 1673-1530
“风景园林,不只是一本期刊。”

城市通风环境的动态模拟与优化研究——以太原都市区为例

Dynamic simulation and optimization of urban ventilation environment: A case study of Taiyuan metropolitan area

  • 摘要: 【目的】随着城市致密化发展,作为消散空气污染与积热重要途径的城市通风环境面临着不同程度的威胁。依据规划发展需求对城市通风环境进行长期动态模拟,进而对通风环境进行有效优化是城市实现可持续发展的重要途径之一。【方法】以太原都市区多时序高精度数据为基础,构建地表气压梯度、地表粗糙度和地表起伏度指标体系以表征城市通风环境,应用随机森林模型测度与模拟2030、2040与2050年的通风环境。【结果】通风环境主要受粗糙度长度和地表温度梯度的影响;研究区域通风在2000-2020年整体呈恶化趋势,尤其在中心城区与晋中市之间;相比于耕地保护情景,生态优先情景对极好与较好通风环境的增加有更积极的影响;依据通风环境在不同情景下的长期动态差异,因地制宜提出城市通风优化策略与规划建议。【结论】结合多维指标体系与随机森林模型预测城市通风环境的长期动态变化,完善了风景园林优化城市气候的策略体系,为建设韧性城市提供理论支持与实践指导。

     

    Abstract: Objective In recent decades, China"s rapid urbanization has led to large amounts of energy consumption and carbon dioxide emissions, triggering significant urban heat island effects and air pollution, which seriously threaten the physical and mental health of residents. How to improve the urban habitat has become the focus of urban planning. Urban ventilation, as an important way to deliver fresh and cold air to built-up areas, can effectively improve the comfort level. Although many international scholars have researched the optimization of urban ventilation, the existing research in China mainly focuses on the measurement of the current ventilation environment in cities. It neglects the long-term dynamic changes of the urban ventilation environment in response to different planning objectives in the process of urban development. Methods This study proposed a research framework with general applicability to simulating future changes in ventilation environment within city-region systems for the first time. Firstly, this study defined five indicators (land surface temperature gradient, roughness length, forest canopy density, elevation variation coefficient, and slope) to evaluate the ventilation environment from three dimensions: surface temperature gradient, surface roughness, and surface undulation. Secondly, a prediction model was constructed based on the random forest algorithm. The multiple scenarios were input into the validated prediction model to simulate changes in the future ventilation environment. Finally, depending on the historical trends in ventilation potential and differences across multiple scenarios within the study area, the applications were proposed for spatial planning and management of metropolitan areas. Results Influenced by the urban development from 2000 to 2020, the ventilation environment of the Taiyuan metropolitan area varies with time, space, and planning objectives. It showed a decreasing trend and an increasing trend in local areas. Patches of better ventilation environments occurred at Jinyang Lake, Fen River, and Park. Several potential ventilation corridors were formed on the east and west sides of the built-up area. Under the scenario of natural development, farmland protection, and ecological priority, the ventilation environment of the study area shows a gradual improvement trend from 2030 to 2050. Specifically, the ventilation environments in different regions show differences in spatial distribution. Under the natural development scenario, the extremely good and good ventilation areas show a trend of significant increase. With the continuous protection of basic farmland, the encroachment of urban expansion on farmland is effectively limited. Under the ecological priority scenario, the increase in good ventilated areas was concentrated in suburban forests and grasslands. Early fragmented ventilation areas gradually expanded and formed ventilation corridors around the built-up area. Conclusion In this study, a dynamic simulation model of the urban ventilation environment was constructed and the spatial distribution of the ventilation environment under different scenarios was mapped. To cope with a series of urban problems caused by urban sprawl and densification, the trends of the ventilation environment in the Taiyuan metropolitan area are predicted and identified, and in this way, a series of targeted optimization strategies are proposed to provide cooler and more comfortable environments for urban residents.

     

/

返回文章
返回