山地城市绿地和水体对热环境的影响

The influence of green space and water on thermal environment in mountainous cities

以典型山地城市——重庆为研究对象,以山地城市特殊用地类型(水体、绿地)对热岛效应的缓解作用为研究内容,通过各时刻温度场图定量分析其影响周边热环境的特性,得出其冷岛效应特征:水体对周围热环境影响较小,研究范围内冷岛效应最高只可达到3℃,且受下垫面类型以及遮阴情况影响很大;绿地对周围热环境影响较大,研究范围内冷岛效应可高达7.5℃。引入形状指数、绿化率、绿地面积、海拔高度建立公园绿地5个时刻冷岛强度统计模型,分别与冷岛强度进行多元线性回归,发现绿地面积与冷岛强度的相关性最高,形状指数与冷岛强度全天都呈现出显著的负相关。统计模型R2值大,模型解释程度较高,研究成果可以为山地城市的规划设计提供有益的参考。

Chongqing,a typical mountainous city,is taken as the research object,and the mitigation effect of special land types(water and green space)on the heat island effect in mountainous cities is taken as the research content.The characteristics of its influence on the surrounding thermal environment were quantitatively analyzed by the temperature field diagram at each time,and the characteristics of its cold island effect were obtained as follows.Water has little influence on the surrounding thermal environment,and the maximum cold island effect can only reach 3℃,in the study cope,which is greatly influenced by the type of underlying surface and shade condition.The green space has a greater influence on the surrounding thermal environment,and the cold island effect can be as high as 7.5℃in the study area.The statistical model of cold island intensity was established by introducing shape index,greening rate,green area and elevation for five moments of park green areas,and multiple linear regressions were conducted with cold island intensity respectively,and it was found that the correlation between green area and cold island intensity was the highest,and shape index and cold island intensity showed a significant negative correlation throughout the day.The statistical model has a large R~2 value and a high degree of model interpretation,and the research results can provide useful references for the planning and design of mountainous cities.