7 - Future research for tropical UHI

Abstract

This study is a full synthesis of modern scientific and applied research on urban heat island (UHI) phenomena in tropical urban climate from its formation to mitigation. The study begins with an outline of constituents of urban thermal environment and their relation to surface energy balance (SEB). This develops a comprehensive concept of tropical UHI and related microthermal interaction in various building environments. It explains the physical principles governing the formation of distinct urban microclimates, and it then illustrates how this knowledge can be applied to mitigate the undesirable consequences of swift and haphazard urban development and help create more sustainable and resilient cities. With urban climate science, now a fully fledged growing field, this timely book fulfills the need to bring together the disparate parts of urban climate research in tropical cities into a coherent framework. This book discusses various measurement techniques that are employed for better understanding the UHI pehomena, e.g., in situ micrometeorological monitoring, thermal remote sensing for mapping, scaling urban thermal field, mesoscale urban model simulation of city-scale UHI through modeling approach, and forecast. This includes scaling of UHI on the basis of long-term seasonal thermal parameters by using probabilistic and high-level machine learning techniques and finally examines the commonly used UHI mitigation strategies in tropical context. The absence of mitigation strategies (i.e., considering energy demand, thermal comfort, air pollution, and urban building architecture) for tropical cities has shown a dilemma in implementing climate and water-sensitive urban design. The study identifies the effectiveness of different UHI mitigation strategies through microclimate simulations—cool pavement, cool roof, green roof, and cool city—for the three different urban morphologies like open low-rise, compact low-rise, and mid-rise residential areas in tropics. It analyzes the effectiveness of the mitigation strategies in improving thermal discomfort (indoor and outdoor) in different building environments and the role of vegetation in determining SEB in tropical cities. It is to help developing innovative applications and materials to reduce building energy use, reduce summer peak electricity demand, improve ambient air quality, and reduce global warming.