Urban green space optimization based on a climate health risk appraisal – A case study of Beijing city, China.

• A health risk appraisal (HRA) system for urban heat island (UHI) was proposed. • Thermal environment changes in Beijing and health risks were identified. • A genetic algorithm simulated green space to suggest planning improvement measures. • Beijing UHI impacts respiratory diseases, cardiovascular diseases, and mental health. • Several suggestions were made to improve the thermal environment in Beijing. Urban heat islands (UHI) and global climate change pose serious threats to human health, making health risk appraisal of urban space as well as the planning and improvement of green space important research projrcts. Meteorological sites, satellite images, electronic maps, questionnaire survey data, statistical yearbooks, ArcGIS spatial analysis technology, MATLAB matrix analysis technology, remote sensing inversion, and ground-object extraction technology were used in this study to evaluate how changes in Beijing's urban thermal environment influence the health of residents. A genetic algorithm was used to optimize the simulation of green space, based on which, different measures were proposed to improve planning. The results show that areas of greater UHI impact on respiratory diseases, cardiovascular diseases and emotional health are mainly concentrated south of the North Second Ring Road in central Beijing. Furthermore, low-level influence areas are highly connected and clustered, while the high-level influence areas are distributed in clusters. The intelligent optimization and simulation of green space show that it exhibits a spatial distribution potentially with building green wedges and cooling corridors. Based on apprasial on health risk impact, analysis on health and climate zone, as well as optimization and simulation of green space, measures such as cooling nodes, urban blue axes, green rings, pergolas, and ventilation corridors are proposed to improve the comfort of urban living environments as well as reduce risks associated with health and environment. [ABSTRACT FROM AUTHOR]