EFFECT OF TREE CANOPY SHAPE AND SIZE ON AVERAGE SURFACE TEMPERATURE IN THE TROPICAL ENVIRONMENT

Abstract

Trees are essential to our lives, and this is especially so in the tropical environment context where countries are facing the already immense heat. This problem is more evident in urban areas as compared to suburban areas due to the urban heat effect as researched by Howard Luke. The difference of temperatures between urban and suburban areas can exceed 10 degrees Celsius. The main root of this difference is because of the heat absorption by building, asphalt roads, concrete surfaces and in other words, Urbanization. Vegetation is one of the leading solutions for mitigating the urban heat island effect. It has the ability to remove the some of the urban heat with transpiration and shade provision. With proper planning and optimising the benefits of the trees, urban designers can reduce urban heat from releasing to the urban environment more effectively. There are many types of trees in the world. One of the ways to look at it is to catergorise these trees into canopy shapes. This study proposes that different types of canopy shape trees result in different temperature reduction and shade provision. The solar transmittance of the tree, tree heights and tree diameter are some of the variables that affect the difference in shade area and surface temperature as well. Simulations were carried out to analyse the effects individually. Qualitative and quantitative results of the simulations pointed out that the conical-shaped tree produces the highest temperature reduction out of all shapes and followed by the weeping-shaped tree. The research outcome also implies that a shorter tree height and a bigger tree width will result in lower surface temperature. All these functional attributes do affect the effect of the trees and the shade provision. With this useful information, urban designers would be able to quickly identify the kind of tree shape and tree opacity that they want to apply to produce the desired environment for their users while mitigating the UHI effect.