基于无人机热红外遥感的城市地物表面温度特征分析

Analysis on Surface Temperature Characteristics of Urban Ground Objects Using UAV Thermal Infrared Remote Sensing

揭示城市下垫面复杂地物表面温度的时空异质性对更加精细的城市热环境管控具有重要意义。本研究在夏季高温天气下利用无人机搭载热红外成像仪对路面、屋面、绿色空间3类下垫面表面温度日间变化特征进行连续监测,并定量分析各下垫面地物材质及其组分配置对表面温度的作用规律。结果表明:1)3类下垫面日间表面温度均在12:00—14:00时达到峰值,但屋面、路面、绿色空间的日间变化幅度存在较大差异,分别为26.78℃、22.53℃、13.74℃;2)同种下垫面类型不同材质地物的表面温度存在显著差异,其中浅色沥青卷材、瓷砖、绿色屋顶3类材质屋面比屋面平均表面温度低5~7℃,混凝土、荷兰砖2类材质路面比路面平均表面温度低约3℃;3)不同类型下垫面的表面温度相互影响不明显,绿色空间对临近下垫面温度的影响仅限于植物遮阴范围;4)基于下垫面组分配比构建了1套适用于城市地块控规管理和详细设计的地表温度预测模型。研究结果较好地弥补了卫星遥感数据因时空分辨率局限造成的对复杂地物表面温度变化机制揭示的不足,同时为凉爽城市下垫面的冷却材料选择与配置提供科学参考。

Diurnal surface temperatures variations of pavement,roof and green space in a high temperature summer day were monitored continuously by an unmanned aerial vehicle(UAV)equipped with a high-resolution thermal infrared imager.Complex influences of underlying surface ground object materials and their compositions on surface temperatures were then investigated.The results show that:1)Surface temperatures of ground objects all reached the peak from 12:00-14:00,while surface temperature gradients varied among different ground objects,with roofs for 26.78℃,roads for 22.53℃,and green spaces for 13.74℃.2)Surface temperatures of the same ground object types varied significantly due to the impact of their material properties.Specifically,average surface temperature of the roof made of light-colored asphalt coil,ceramic tile or vegetation was 5~7℃ lower than that of the overall roofs,while the average surface temperature of concrete and Dutch brick pavement was about 3℃ lower than that of the overall pavements.3)Thermal interactions between different underlying surface types were not significant,and the effect of green space on the ambient underlying surface was dominated by the trees shading.4)A prediction model of land surface temperatures suitable for the control and detailed design of urban blocks was proposed according to the proportions of ground object compositions.