Mapping the urban microclimatic spatial distribution in a sub-tropical high-density urban environment

Abstract

Understanding the urban microclimatic spatial distribution and its impact on thermal comfort is important for integrating climatic consideration into urban design process. This article presents a case study in Tsim Sha Tsui and Tai Po of Hong Kong densely built-up areas to investigate the spatial distribution of microclimatic condition. Air temperature (Ta), wind speed (v), relative humidity (RH) and globe temperature (Tg) of 87 locations in two selected sites were measured on a summer day and a winter day respectively. Physiological Equivalent Temperature was calculated to analyse the thermal comfort condition in two sites. Both numerical simulation and geographical mapping approach were used for the estimation of the microclimatic spatial distribution. Results show that the influence of urban morphology on the microclimatic spatial distribution can be well investigated by using numerical simulation while geographical mapping based on measured data shows higher estimation accuracy due to the consideration of anthropogenic heat and other factors associated with human activities. In summary, this article presents a pragmatic approach of mapping the urban microclimatic spatial distribution that can be referenced by architects and urban designers to raise climatic considerations for designing better cities.