【摘要】 城市热环境与人们生活息息相关,研究城市热环境的分布及影响因素可以为热环境的改善和城市景观的规划提供理论支撑。为定量分析绿化设施对室外近地面温度的影响,文章在利用无人机航测数据的基础上,运用ENVI-met对研究区域建立实际和无植被2种方案并进行热环境模拟对比分析。结果表明:无人机倾斜摄影能快速获取研究区正射影像和高精度三维信息,用ENVI-met建模更加灵活,且成本更低;结果与实测的相关系数>0.9且均方根误差(RMSE)达0.6℃,模拟结果能够较好地反应研究区温度的分布情况;植被和草坪具有明显的降温效应,无植被情况研究区高温区(>36℃)面积增加34%,表征人体热反应(冷热感)的评价指标PMV>4.5的面积增加17%;在垂直方向上,植被对近地面的降温效应可伸展至15 m。更多还原

【Abstract】 The urban thermal environment is closely related to people’s life. Studying the distribution of urban thermal environment and its influencing factors can provide theoretical support for the improvement of people’s thermal environment and the planning of urban landscape. In order to quantitatively analyze the influence of vegetation and afforestation on the outdoor near-surface temperature,the ENVI-met was used to simulate and compare the thermal environment between the real and the non-vegetation scenarios in the study area on the basis of unmanned aerial vehicle( UAV) data. The research results show that UAV tilt photography can quickly and cost-effectively acquire orthophotos and high-precision 3 D information in the study area,which is more flexible for ENVI-met modeling. The correlation coefficient between the simulation result of ENVI-met and the observed result reach above 0. 9 and the RMSE reaches 0. 6 ℃. The model can reflect the temperature distribution of the study area. Vegetation and lawn have significant cooling effect. In the nonvegetated area,the high temperature area( greater than 36℃) in the study area increases by 34%,and the area of PMV > 4. 5 increases by 17%. In the vertical layer,the cooling effect of vegetation on the near ground can be extended to 15 meters.更多还原