湿热地区大学校园室外步行环境微气候评价研究——以华南理工大学为例

Microclimate Evaluation of the Outdoor Walking Environment of University Campuses in Humid Tropical Regions:A Case Study of South China University of Technology

以华南理工大学五山校区为例,对湿热地区大学校园步行环境的热环境和风环境进行评价研究,探究周边水体、树木遮阴和建筑遮阴三个主要因素对步行环境微气候的影响,研究不同因素的组合与风环境指标差值以及热环境指标差值的相关性。选取夏季和春季具有代表性的不同因素组合测点的单日测量数据,研究华南理工大学步行环境春夏两季的日间风环境指标和热环境指标变化特征,评价不同因素组合在步行环境设计和优化过程中的作用和区别,以此得出多种步行环境微气候舒适的局部模型,以期为湿热地区大学校园的室外步行环境微气候改善提供参考借鉴。

The thermal and wind characteristics of the university campus walking environment in humid and hot areas were evaluated in this study,taking the Wushan campus of the South China University of Technology as a case study.The influences of three main factors(surrounding water bodies,tree shade,and building shade)on the microclimate of the walking environment were investigated.The combination of different factors and the corresponding differences in wind environment indexes and thermal environment indexes were studied.The study focused on the core part of the campus,combined with the road infrastructure survey,and divided the measurement points into 7 categories according to combinations of influencing factors.The observation points were then measured at six typical periods between classes according to the travel activity patterns of students.The wind speed,air temperature,relative humidity,and heat index of each measurement point were recorded by walking at fixed points.Representative single-day measurement data in summer and spring were selected for analysis to study variations in the daytime wind environment index and thermal environment index.In addition,the roles of different combinations of factors in the design and optimization of the walking environment were judged.Some conclusions could be drawn:(1)The wind environment index of the walking environment is less affected by seasonal changes,while the thermal environment index is more affected by seasonal changes.The heat index,temperature,and relative humidity are much higher in summer than in spring.Hence,the key to improving the microclimate of walking environment is improvement of the thermal environment.(2)Among the different combinations of factors,a combination of three factors is better than a combination of two factors for improving the microclimate of the walking environment,because the combination of three factors can improve both the wind environment and thermal environment.(3)The wind and thermal environment indexes of the walking environment were the worst in the control group without the influence of three factors.The wind and thermal environment indexes of the other groups were better than those of the control group,indicating that single factors had an effect on the microclimate of the walking environment.(4)The surrounding water bodies mainly improved the microclimate of the walking environment by influencing the wind environment,and the tree shade and building shade mainly improved the microclimate by influencing the thermal environment.Therefore,water bodies are less effective in improving the microclimate of the walking environment than buildings or tree shade when the walking environment is a single factor.(5)There was no significant difference between heat index and temperature in spring,while the heat index was much higher than the temperature in summer.The relative humidity in summer was higher than the relative temperature in spring.The relative humidity and temperature influence the heat index together.In summer,the temperature that people can feel in the walking environment is far higher than the actual temperature.(6)In practical projects,we should not simply consider a single factor to improve the microclimate of the walking environment.The primary goal is to improve the thermal environment in hot and humid areas and create a shaded environment by combining both building and tree shade.Given limitations in planning layouts and architectural design conditions,it is suggested that thermal environments be improved by creating tree shadows as much as is possible from the perspective of landscape design.Meanwhile,water bodies should be designed in combination with the walking environment to provide open spaces to improve the wind environment.Based on the data analysis,four local models of microclimate comfort in the walking environment were provided,aiming to provide a reference for the improvement of outdoor walking environment microclimates in university campuses in hot and humid regions.However,this study still has some limitations.It focuses on objective microclimate environmental indexes;analyzes thermal environment by measuring heat index,temperature,and relative humidity;and analyzes wind environment by measuring wind speed.In addition,the outdoor thermal comfort of the human body can be further analyzed by measuring physiological equivalent temperature.