关键词: 城市下垫面, 热环境, 地表温度, 季节变化, 时空变化

Abstract:

Surface temperature characteristics of six typical underlying surfaces, namely, asphalt pavement, cement pavement, grass, marble pavement, pavement bricks and grass-planting bricks, were observed with thermal infrared imaging technology. The diurnal and seasonal variations of surface temperature of different underlying surfaces were systematically analyzed. By means of the standard deviation (SD), the temporal and spatial microclimatic dynamic characteristics of different underlying surface temperature were revealed. The results are as following. 1) Diurnal variation of surface temperature of different underlying surfaces present unimodal pattern, diurnal variation of grass surface temperature changes greatly from season to season. Asphalt surface temperature is highest among the whole year, having a great effect on thermal environment while temperatures of grass-planting bricks and marble pavement are the lowest, having a relief effect on thermal environment, especially in summer. 2) The daily average temperature of different underlying surfaces are higher than air temperature, showing that underlying surface keeps heating the air throughout the year. 3) The underlying surface temperature is strongly affected by air temperature, relative humidity and solar radiation. Air temperature and solar radiation are positively related with surface temperature, showing that air temperature and solar radiation play a role in warming the land surface. On the contrary, relative humidity is negatively correlated with surface temperature, turning out that relative humidity plays a role in cooling the land surface. 4) Grass-planting bricks have a more stable thermal environment than grass and marble bricks. Temperature changing characteristic of asphalt pavement best represents the spatial and temporal variation characteristics regarding the temperature of underlying surface. The results have certain reference significance for knowing thermal environment of different urban underlying surfaces, while providing scientific evidence for alleviating urban thermal environment.

Key words: urban underlying surfaces, thermal environment, surface temperature, seasonal variation, spatial and temporal variation