Green facade is an important strategy to improve the urban eco-environment and reduce the negative effects of human activities in central districts of cities which are land-scarce and lack green spaces. We first summarized the limiting factors for the construction of green facades locally and internationally. Then, we used the Xinjiekou District of Nanjing City in China as a case study area, and selected the wind environment, solar environment, and physical build environment that might impact the potential development of green facades as key factors to quantitatively analyze singlely by geographic information systems (GIS) and computational fluid dynamics (CFD). Finally, the potential area to develop green facades was assessed through a multi-factor overlay analysis. The results showed that 17726 m2 of wall spaces in the Xinjiekou District had a high potential for facade greening, accounting for 30.8% of all exterior wall space under a height of 12 m and 17.3% of the entire study area. Sunlight was a key limiting factor in determining whether a green facade should be developed. Irrigation was identified as another important factor that might strongly affect the growth of vertical vegetation in urban environment. The spatial distribution of walls suitable for facade greening was uneven, with an "inner-high and south-high" spatial pattern. Our results would help to guide the design and development of green facades in Xinjiekou, and also provide a reference for planning and utilizing green wall space projects in other built and dense urban areas.
垂直绿化已成为建设用地紧张、绿化空间缺乏的城市中心区提升生态效能、缓解人为活动负面影响的重要策略.本文在总结国内外垂直绿化建设影响因素的基础上,以南京市新街口地区为例,选择风环境、光照环境、建筑及周围环境作为影响研究区垂直绿化发展潜力的主要因子,基于地理信息系统(GIS)和计算流体动力学(CFD)对其进行单因子定量分析,并通过多因子加权叠置方法对研究区垂直绿化发展潜力进行综合评价.结果表明: 研究区12 m以下建筑立面中,较为适宜进行垂直绿化建设的面积为17726 m2,占比为30.8%,为研究区总面积的17.3%;光照对垂直绿化适建性影响程度较大,而建筑及周围环境中的“灌溉”因子是影响垂直绿化建设的重要限制性因子;适于垂直绿化建设的建筑立面在空间上分布很不均衡,多集中于研究区内部和建筑南侧.研究结果可为研究区垂直绿化的规划和建设提供重要参考,也为其他城市高密度地区实现建筑立面的科学规划与有效利用提供了重要的方法借鉴.
Keywords: Nanjing City; computational fluid dynamics (CFD); green facade; potential assessment; urban center.