基于细颗粒物模拟和负离子评价的高密度城市住区空间形态研究

The environmental quality of urban environment is an important research area of social concern and the important research field of human settlements. Under the new urbanization, high-density urban residential environment is an important factor in urbanization and urban competitiveness. Under the background of promoting the construction of new urbanization and paying attention to the health of the population, this project combines the multidisciplinary perspective to reveal the spatial pattern of high-density urban residential space by using 3S spatial analysis technology, and summarizes the spatial characteristics and design indexes of high-density urban residential area; With fine particles, negative air ions and micro-climate environment as the starting point interpretation of high-density urban residential space form under the influence of the fine particles, negative air ions and micro-climate formation mechanism, distribution and its correlation, and evaluation of residential area air quality; The use of WRF And CFD different scale simulation tools and methods, coupled with high-density urban residential space shape and air quality and micro-climate numerical model to explore based on improving air quality and regulation of micro-climate of high-density urban residential space shape design method; fully integrated into the ecological civilized ideas and principles to build a high-density urban residential space model and design parameters of a reasonable threshold, so that the residential space form to a healthy state for high-density urban residential planning and design innovation and high quality living environment to provide new perspective.

城市环境空气质量是社会关注的热点问题和人居环境学科重要的研究领域，新型城镇化背景下高密度城市住区环境更是体现城镇化发展水平和城市竞争力的重要要素。在国家推进新型城镇化建设和关注人群健康的研究背景下，本项目融合多学科视角，运用3S空间分析技术揭示高密度城市住区空间格局，总结高密度城市住区空间形态特征和设计指标；以细颗粒物、负离子和微气候环境为切入点，阐释高密度城市住区空间形态影响下的细颗粒物、负离子和微气候的形成机理、分布规律及与其相关性，并评价住区空气质量；运用WRF和CFD不同尺度模拟工具和方法，耦合高密度城市住区空间形态与空气质量和微气候的数值模型，探讨基于改善空气质量和调节微气候的高密度城市住区空间形态设计方法；全面融入生态文明理念和原则构建高密度城市住区空间模型与设计参数的合理阈值，使住区空间形态达到健康状态，为高密度城市住区规划设计方法的创新和高品质人居环境的建立提供新的视角。

首先，以夏热冬冷地区高密度城市住区为研究对象，根据空间布局、建筑高度、道路交通、景观绿化等环境特征，确定12个样点进行实测并评估空气质量。结果表明：①PM2.5和空气负离子浓度均随季节变化较为明显，前者冬季最高，过渡季次之，夏季最低；后者反之。PM2.5和空气负离子浓度日变化均呈现双峰双谷趋势，且阴雨天和晴天差异较大，最大增幅达200%。空气负离子浓度与温湿度呈正相关，偏相关系数分别为0.212和0.279，受相对湿度影响大于受温度影响。②运用Envi-met模拟PM2.5和建筑环境因子分布，结合GIS对住区空间形态特征进行可视化分析。得出混合围合式PM2.5浓度最低，全高层围合式PM2.5浓度最高；南北布局路网更有助于PM2.5浓度的空间扩散，且距离污染源道路越近，空间布局形态对PM2.5浓度影响越大；乔灌草复层绿化PM2.5浓度最低，草地单层绿化PM2.5浓度最高。③根据实测数据和模拟结果，得出住区空间形态与热环境影响较大，进一步应用GIS与3D集成的天空开阔度测算系统，分析住区空间形态指标与天空开阔度的相关性，得出布局形式、容积率和建筑密度等指标关联性较大。. 其次，筛选了40个容积率2.5以上的高密度住区，归纳出8种典型模块，运用实测和模拟分析典型模块的PM2.5浓度分布特征。结果表明：住区内部PM2.5浓度整体随高度增加而逐渐降低；点式行列式布局最利于PM2.5扩散，围合式中间公共区域PM2.5较低，宅间PM2.5较高；上风口方向布局封闭式住宅单体；增加横向宅间距可以有效减少PM2.5堆积。. 最后，以容积率2.66的行列高层全包围式为高密度住区典型模块，分析容积率、建筑密度、建筑间错落度、布局形式、建筑单体位置与天空开阔度的相关性。通过显著性检验判断确定建筑密度对天空开阔度影响最大，其次为容积率、建筑间错落度。为改善微气候和降低热岛效应，住区容积率应小于2.72，建筑密度应小于19.46%，建筑间错落度应大于7m。并建议应优先选用行列式或斜列式平面布局，较高建筑应临住区边界布置，可采用中间低两侧高式或高层两侧包围式，以获得更高的天空开阔度，从而营造健康的人居环境。