In the context of climate change, more frequent and intensive exposure to heat stress is observed in many cities worldwide. A significant increase in the number of hot summer days with daily maximum temperatures over 30 °C has also been determined for Cologne in recent decades. Since such hot days pose extensive health risks and consequences for the human organism, and considerably limit the performance of the affected population, a strategic adaptation of cities to climate change is urgently required. In order to reduce the exposure to heat in cities and to improve the urban microclimate, various adaptation measures are developed and implemented. Such mitigation strategies to increase thermal outdoor comfort include for example the cooling effects of green infrastructures such as parks or urban forests, water bodies, shading by trees, green facades, green roofs, light surfaces and much more.

The aim of this research project is to measure and model the microclimate of a 15 hectare study area in the southern city of Cologne in order to analyze the microclimatological effects of these adaptation measures. An ENVI-met model is parameterized to simulate the urban microclimate. With this model for calculating the urban microclimate down to the square meter, various adaptation and planning scenarios are implemented. On the basis of appropriate modeling and future projections, specific forecasts are made of how the urban climate in Cologne's Südstadt can be improved by strategic urban planning and the application of such adaptation measures. In addition, various climate change projections until 2099 are developed assuming the HadCM3 future emission scenarios.

For the parameterization of the ENVI-met model, urban, ecological and meteorological input data are used, which are enriched by remote sensing, cadastral databases and site inspections. A model calibration and validation is implemented based on in-situ measurements in the study area. For this purpose, a dense network of small NETATMO weather sensors with ultrasonic anemometers is set up to measure air temperature, relative humidity, wind speed and wind direction in Cologne's Südstadt. These sensors are calibrated against built up research grade meteorological stations in the study area. The use of inexpensive NETATMO weather sensors also provides opportunities to activate citizens and local actors to participate in microclimate research and thus foster adaptation to the consequences of climate change.

The research project is embedded into the INGENIoS context and also represents interactions with the CUbiK project on the other side of the Rhine in Cologne.