基于CFD对沈阳不同绿地景观格局大气环境效应分析

Atmospheric Environment Effect of Different Green Space Pattern in Shenyang based on Computational Fluid Dynamics

目的数值模拟综合分析城市绿地规划方案与风速、污染物质量浓度和地表温度的三维时空变化关系以及相互影响,提出最优的城市绿地空间结构优化方案.方法结合遥感与地理信息系统空间分析技术,运用计算流体力学(CFD)模型对不同绿地预案影响下的沈阳市夏季城市大气环境效应进行数值模拟对比分析.结果在增加相同公园绿地面积的前提下,城市绿地的空间位置对城市风速、SO_2以及地表温度的空间扩散具有明显的影响;植被类型为针阔乔灌混交林,植被覆盖率为60%的绿地预案三中,城市高风速区域的风速覆盖率达到了42.94%;质量浓度低于0.051 69mg/m^3的SO_2覆盖率达到了79.83%;城市高温区域的地表温度覆盖率相对最低.该预案中的绿地布局能较好地将外围较低的冷空气引入城中,有效地缓解了城市大气环境问题.结论城市绿地的植被类型、植被覆盖率以及空间布局与城市大气环境问题的改善关系密切.利用CFD动态模拟大气环境运行状况,优化绿地空间布局,是城市绿地系统量化规划的新思路.

The aim of this paper is to analyze the relationship and influence between urban green space planning and three-dimensional space-time change of speed,pollutant mass concentration andland surface temperature by numeric simulation so as to propose optimal planning strategies of green space landscape pattern. Urban atmospheric environment with different green space scenarios in summer was simulated by Remote Sensing（RS） and the spatial analysis technology in Geographic Information System（GIS）,combined with Computational Fluid Dynamics（CFD）model in Shenyang. The simulation results showed that：in the premise of increasing the same park area,different locations of urban green spaces had a manifest influence on wind speed,SO_2 mass concentration and the spatial diffusion of land surface temperature. in the third scenario which wegetation types for needle shrubbery,mixed forests and vegetation coverage rate of 60%,the coverage area of high wind speed is 42. 94%; the coverage area of SO_2 concentration with lower than0. 051 69 mg /m-3 is 79. 83%;The coverage area of high surface temperature is minimum comparison with wind speed and SO_2. In this layout of urban green space cold air will be brought into the city to alleviate urban atmospheric environment problems. In this article,the vegetation types of urban green space,vegetation coverage and space layout are closely related to the improvement of the urban atmospheric environment problem. It is a new idea for urban green space system quantitative planning and optimizing green space layout through dynamic simulating atmospheric environment running status by CFD.