DOI: 10.15986/j.1006-7930.2020.01.015
下垫面是形成微气候的关键因素,为了研究其对夏季城市局地微气候的影响机制,选择4种具有代表性的城市下垫面(沥青路面、混凝土路面、铺面砖地面、草地)作为研究对象,对下垫面热环境参数进行测量.分析了不同下垫面微气候特征和地表温度变化特征,以及下垫面地表温度和气象参数、物理性质的影响关系,对比研究了不同下垫面的微热环境影响,结果如下:不同下垫面地表上方空气温度、太阳辐射、相对湿度和风速共同构成的下垫面微气候环境存在差异,不同下垫面地表温度的日变化一般呈先上升后下降的单峰形态,沥青地表温度在全天均高于其他下垫面; 气温、太阳辐射以及空气相对湿度与下垫面地表温度的关联性显著; 材料热物理性质会影响下垫面地表温度表现,但影响程度不同,由高至低依次为热扩散率、比热容和反射率; 四种下垫面热环境舒适度从高到低依次是草地、混凝土、铺面砖、沥青.本研究可为优化城市热环境设计提供科学依据.
The underlying surface is a key factor in the formation of microclimates. In order to study its effect on the microclimate in summer, four representative urban underlying surfaces(asphalt pavement, concrete pavement, pavement brick floor and grassland)were selected as objects for observation. The thermal environment parameters of the underlying surface were measured by measuring instruments. On this basis, the microclimate characteristics surface temperature variation characteristics of different underlying surfaces are analyzed; so are the relationship between surface temperature and meteorological parameters, physical properties of underlying surfaces. The micro-thermal environmental impacts of different underlying surfaces are compared and studied. Results are as follows:There are differences in the microclimatic environment of the underlying surface composed of air temperature, solar radiation, relative humidity and wind speed above the surface of different underlying surfaces. The diurnal variation of surface temperature of different underlying surfaces generally presents a single peak pattern, which rises first and then decreases. The surface temperature of asphalt is higher than that of other underlying surfaces in the whole day.Temperature, solar radiation and air relative humidity have significant effects on the temperature of underlying surface. The thermal physical properties of materials can affect the surface temperature performance of underlying surface, but the degree of influence is different. From high to low, the order is thermal diffusivity, specific heat capacity and reflectivity; The thermal environment comfort degree of the four kinds of underlying surfaces from high to low is grassland, concrete, paving brick and asphalt in turn. Research results have certain reference significance for understanding the thermal environment of different urban underlying surfaces, and can provide scientific basis for alleviating the urban thermal environment.
