Vegetation cover and plant-trait effects on outdoor thermal comfort in a tropical city

An increase in urban vegetation is an often proposed mitigation strategy to reduce heat and improve outdoor thermal comfort (OTC). Vegetation can alter microclimate through changes air temperature, mean radiant humidity, wind speed. In this study, we model how street tree ground cover their structural, optical, interception, physiological traits control the diurnal cycle of OTC different densities a tropical city (Singapore). For purpose, perform variance based sensitivity analysis ecohydrological UT&C. Model performance evaluated comparison with local measurements assessed Universal Thermal Climate Index (UTCI). We find pronounced daily effects on UTCI. Tree fraction more efficient decreasing UTCI during daytime, while higher vegetated provides cooling night. Generally, increasing fractions do not deter OTC, except certain some periods day. average reduction compared change (0.9 – 2.9 °C vs. 0.7 1.1 midday, 10 month average). The humidity related plant transpiration prevents further However, choice enhancing decrease hot periods. These results inform planners selection amount achieve feasible improvements cities.