Differences in microclimate of paved and green areas

Rising temperatures in the urban environment due to climate change are leading to an increased interest in building materials and green infrastructure and their impact on the urban microclimate. When considering green infrastructure often the soil moisture is neglected. This publication explores this issue by measuring the microclimate over a sealed surface and a lawn under different moisture conditions. The measurements are compared with simulations using the ENVI-met software.

The results of the measurements show that during dry periods the temperature difference between the lawn and the paving becomes smaller and can even lead to higher temperatures over the lawn. During humid periods the temperature difference becomes greater, with higher temperatures over the paving. In terms of PET, the differences between the two surfaces are between 0.6 and 1.7 K.

The comparison between measurements and simulations were used to explore the reliability of the two available radiation models in the software in comparison to the measurement results. Concerning DBT, the deviations are very small. Deviations on a larger scale are found for MRT using both radiation models. Both findings are in line with the literature. The comparison of both radiation models shows that for the paving the “solar radiation model” performs better. Regarding the lawn both models perform almost equally.