Improving habitability in open spaces through bioclimatic shading strategies in Seville (Spain)

Climate change and the global pandemic caused by COVID-19 highlight the need to create habitable outdoor urban spaces. Mitigation techniques that improve environmental conditions are essential in cities with high temperatures. For this reason, an innovative solar control technique based on a green structure was designed where trees are the centrepiece. The innovative structure is installed in a square in the city centre of Seville (Spain). The vegetation area was increased, where the expected shadow nearly reaches 100% of the covered square. However, the trees planted are in the young stage, and for that, an artificial covering is introduced to adapt its geometry to the growth of the trees and the climate seasons. The urban environment is characterized by on-site measurements. Different scenarios are studied as a function of tree growth. Computational Fluid Dynamics simulations in ENVI-met are used for this purpose. In addition, the thermal comfort analysis is carried out using the COMFA model. Three factors are examined: surface temperature, air temperature, and incident radiation. The vegetation reduces surface temperatures by up to 12 °C. Out-of-comfort hours are reduced by 21% using an artificial cover, and compared to 30% when the vegetation reaches the adult stage is a mitigation solution.