The Potential of Green Spaces in Mitigating the Urban Heat Island Effect : A Case Study of Chulalongkorn University Centenary Park

Sutharee Yangpaiboon and Ponthep Meunpong



Densely populated urban areas are usually affected by urban heat islands (UHI) and green spaces can have a cooling effect and help to mitigate UHI problem. This research aimed to compare the effect of different tree crown covers on the ambient air temperature and relative humidity through a model developed using the ENVI-met program. Such analysis can be used to efficiently manage urban green spaces. The study consisted of verifying the reliability and accuracy of the weather parameter forecast model in the ENVI-met program. The goodness of fit of the air temperature and relative humidity, obtained from simulation models and the actual data measured by the meteorological department, was determined by using statistical parameters like coefficient of determination (R2) and Root Mean Square Error (RMSE). Three tree crown cover scenarios were tested, which included 1) park with an absence of perennial trees, 2) actual current park conditions, and 3) park conditions using a 10 year forecasted tree growth. The results showed that scenario 3, with the largest crown cover contributed to a reduction in air temperature of approximately 5.18 ?C due to increased air ventilation. Thus, tree planting can effectively mitigate the ill-effects of UHI. In addition to vegetation composition, other park elements and quality of urban green spaces, as well as climate characteristics, can significantly affect the green areas. Therefore, future studies, focusing on different elements, should be conducted and applied in the spatial design of green spaces for effective reduction and mitigation of UHI.