杭州市临安区局地气候区的下垫面组成与空间结构对冬季气温的影响

适宜的城市规划和景观设计可以有效缓解热岛效应等城市气候因素对人居环境带来的负面影响。揭示城市户外热环境的时空变化特征及其主要影响因子，是调节和改善城市气候环境的理论基础。针对具有特定气候条件和城市形态的杭州市临安区，调查冬季不同局地气候区空气温度时空变化特征，深入分析了景观下垫面组成和空间结构对气温的影响。结果表明，在冬季午后，不同测点温度差异较大，最大温差达3.2℃,且气温主要受测点周围环境影响；到了晚上，各局地气候区内部温差较小，均在0.7～0.9℃,而不同局地气候区之间差异明显，最大温差达2.6℃。通过回归分析发现，冬季午后气温主要受到下垫面结构的影响，而夜晚气温主要受到测点周围100～200 m范围内下垫面组成的影响，此时气温随绿化覆盖率的增加而降低，随建筑覆盖率的增加而升高。研究表明，在城市规划与景观设计过程中，合理控制绿化和建筑的组成比率，优化景观下垫面的三维空间结构，有助于改善城市户外热环境。

Effects of Land Cover Composition and Structure on Air Temperature in Winter Based on the Local Climate Zone Scheme

Taking the Lin’an District of Hangzhou as an example,and based on the local climate zone classification system,this study compared the difference in air temperature in winter within and among different local climate zones.The land cover of these climate zones leading to the difference was further discussed.The results showed that in winter afternoon,the temperature varied greatly from different measurement points,with a maximum temperature difference of 3.2 ℃,and the temperature was mainly influenced by the environment around the measurement point.At night,the temperature difference within each local climate zone was small,with a temperature difference between 0.7-0.9 ℃,while the difference between different local climate zones was obvious,with a maximum temperature difference of 2.6 ℃.Regression analysis indicated that air temperature was mainly affected by structure of land cover in the afternoon and by composition of land cover within 100~200 m radius around the measuring sites in the evening.Air temperature rose as plant coverage increased and dropped as building coverage increased.The results show that in the process of urban planning and design,reasonable control of greening and building composition ratio will help to improve the urban outdoor thermal environment.