Thermal measurement campaign in three streets of Strasbourg to study interactions between trees and facades

The TIR4sTREEt project studies the urban climatology in Strasbourg, focusing on the behaviour of trees in the city and their role in improving urban thermal comfort during periods of extreme heat. To collect the necessary data for this analysis, a significant number of microclimatic and eco-physiological sensors have been installed for both climatic and tree data acquisitions, respectively. Among others, infrared thermography is used to study the surface temperatures of urban elements and to highlight the interaction between trees and nearby buildings. On the one hand, thermal infrared (TIR) cameras were installed on fixed masts in the study area to continuously monitor and record the temperature of the tree crowns over several weeks, in order to assess, for example, the impact of the tree shading on facades. Additional TIR acquisitions were made at ground level, during specific times of the day using a specifically designed mobile system. On the other hand, miniature temperature data loggers, known as thermo buttons, were placed on the facades at specific locations. Thermal measurements from these thermo buttons will be compared with temperatures extracted from thermal images. In future works, this comparison will allow the measurements to be verified in order to study the interaction between trees and facades. Furthermore, the whole dataset of thermal data will be used to validate the results generated by urban microclimatic modelling software.