The impact of block morphology on urban microclimates: A case study of three cities in cold regions of China

Abstract

There is an increasing concentration of population and more complex block morphology in the urban center of a large city, causing urban microclimate problems such as poor outdoor ventilation and low thermal comfort. The block morphology characteristics of urban centers affect the natural ventilation and solar radiation of block spaces, which are closely related to microclimate. In this article, the effects of block morphology in three typical plain large cities in cold regions of China, including Shijiazhuang, Zhengzhou, and Xi'an, on urban microclimate are studied. These three cold cities have serious high-temperature problems in their urban centers in the summer. To mitigate the block-scale microclimate problem in large cities, a systematic and scientific research approach was established by using typology, morphology, and numerical simulation. This study discovered a series of correlations, including positive correlation, negative correlation, and linear regression relationships, between the microclimate indices at the 1 km² block scale and the quantitative indices of block morphology in the central area of a plain city in a cold region. These relationships can be used to guide the designs and renovations for better block shapes to effectively improve the ventilation conditions, adjust the outdoor temperature, and mitigate microclimate problems.