SOLWEIG - IMPACTS OF VEGETATION ON MEAN RADIANT TEMPERATURE IN SINGAPORE

Abstract

The Urban Heat Island effect is especially dominant in an urban cityscape like Singapore and much research work has been done to formulate planning strategies to mitigate the UHI effect. In seeking to understand the impacts of the built environment on UHI, current software models have found it difficult to simulate large areas to a reasonable accuracy. This paper will first look at testing the validity of the SOLWEIG model in a tropical Asian country, Singapore, to determine the practicality in employing its use. The model will then be used to test the significance of vegetation use on Tmrt in the city. This includes individual tree attributes, and on a more macro scale, the arrangement of a cluster or row of trees. It was found that in individual trees, varying the trunk height, tree diameter and transmissivity all have significant impacts on the Tmrt but this is not so for the total tree height. Having different orientations relative to the sun path and having different spacing between rows of trees can also affect the Tmrt significantly. This study also concluded that having a cluster of small trees is more effective than having only a row of big trees, and average sized bushes in Singapore actually have no significant impact on the Tmrt for a standing person. Further rigorous research can test the validity of the model on larger urban scales in different cityscapes, and different weather conditions, especially since the model is a simplified scale-down of actual environmental condition