Drone-based optimization of numerical simulations of urban heat islands (DROHNIS)

The research project investigates the local climatic effects of urban development, which are becoming increasingly important under the term “heat islands” as a result of climate change. Buildings influence the urban climate in a variety of ways, for example through the storage mass and radiation behavior of surfaces. The aim of the project is to develop high-resolution simulation models for urban structures. These models should be able to simulate precise urban planning decisions and evaluate them in a scientifically sound manner. This will enable cities to specifically evaluate the effects of concrete adaptation measures and proactively contribute to mitigating the consequences of climate change.

As part of the research project, the buildings are recorded using drones equipped with LiDAR sensors, hyperspectral sensors and thermographic cameras. This data will be processed in a numerical simulation program to create a 3D microclimatic model that predicts the behavior of urban heat islands. A central research question deals with the integration of the data into the model through point cloud interpretation and spectral analyses. The aim is not only to map the urban space in three dimensions, but also to capture the materiality of the surfaces.

GIS and CityGML are central tools for considerations on an urban planning scale. CityJSON is examined as a common alternative to CityGML. A major advantage over data from satellite remote sensing is the higher geometric and material resolution of the generated surface model, which focuses on specific areas of the urban space. Inaccuracies due to atmospheric corrections in the spectral analysis are eliminated. The high temporal resolution of the drone flights, which enable a daily mapping of the thermal behavior through multiple overflights in one day, represents a new approach in the evaluation.