Urban micro-climate change evaluation and mitigation solutions-a case from Xi'an, China

The effects of urban climate change have drawn attention to monitoring and evaluating outdoor environment in cities worldwide. Especially in China, rapid, large-scale urban development alongside rapid economic growth has resulted in considerable urban climate change since the 1990s, creating urban environmental problems such as haze. Currently, most of the studies on this matter that are being conducted in China focus on the impact of urban development on urban climate change. Few studies have focused on developing solutions for microscale urban climate change. In this study, four micro-scaled districts in Xi'an were selected to represent the typical building styles that developed in different historical periods. These are a traditional residential district (1950s), a low-rise district (1980s), a mixed-rise district (1970s-2000s), and a highrise district (2010s). The urban climate was here evaluated using the urban environmental simulation system scSTREAM, and the mitigation solutions of urban typology optimizing are proposed in the discussion. The change in the urban micro-climate along with the change in urban typology were indicated, and the proposed solutions indicate in detail the impact of various solutions on different urban conditions. This may which could provide hints for urban climate change mitigation and sustainable urban planning in the future.