基于光纤测温技术的城市地表温度精细化分析

城市景观空间构型与热岛效应关联性较强，研究高时空分辨率的城市不同下垫面地表温度变化，可以更加精细地掌握城市热环境的时空特征。光纤温度传感系统具有实时在线、测温精度高和不受电磁干扰等优点，具备实时、在线、连续开展城市地表温度在线监测的能力。在北京市通州某园区内，选择有太阳辐射的4个时段，对多种类型下垫面的地表温度进行了时间间隔为1 min、空间间隔为1 m的连续4 h、总长度为100 m的实时在线监测。通过对监测时间段内不同类型下垫面地表温度的变化分析，发现这种分布式光纤测温系统能够有效辨识小尺度下地表温度的时间变化性和空间变化性，能有效区分透水和不透水地面，并监测和评估沥青马路地表温度的升温速率以及遮荫效果对地表温度的降温作用。同时，这种监测模式获取的数据能够对地表温度空间序列开展自相关分析，进一步验证了地表温度空间序列在较小尺度上仍然具有自相关性，且距离越近，相关性越大。研究同时表明，光纤测温技术能直接地获取城市热环境的现场真实数据，可以有效应用于小尺度城市热环境的观测与研究。

Refined analysis of urban surface temperature based on optical fiber temperature measurement technology

The spatial configuration of the urban landscape is highly correlated with the heat island effect. By studying the land surface temperature (LST) of different underlying surfaces with high spatial and temporal resolution, we can grasp the temporal and spatial characteristics of the urban thermal environment more accurately. The optical fiber temperature sensing system has the advantages of real-time and high measurement accuracy and immunity to electromagnetic interference, and can monitor the LST in real time and continuously. In a park in Tongzhou, Beijing, four periods with solar radiation were selected, and the LST of various types of underlying surfaces was recorded in four consecutive hours with 1-minute time interval and 1-meter space interval, and the total length was 100 m. By analyzing the changes of LST of different underlying surface, it''s proved that this distributed optical fiber temperature measurement system can effectively identify temporal and spatial variability of LST on a small scale, distinguish between permeable and impervious grounds, monitor the heating rate of the surface temperature of asphalt road, and evaluate the cooling effect of shading on LST. At the same time, data obtained by this monitoring mode enables autocorrelation analysis of LST spatial sequence. The results verified that the LST spatial sequence still has autocorrelation on a small scale, and the closer the distance, the higher the correlation level. Simultaneously, it is confirmed by this practice that the optical fiber temperature measurement technology can be effectively applied to the observation and research of small-scale urban thermal environment.