Examining component-based city health by implementing a fuzzy evaluation approach

Cities have become the most important habitats for mankind in most regions of the world. Many researchers and organizations have attempted to evaluate the states of cities from the perspective of their functionalities. However, the comprising components of a city, which provide these functions, have not been evaluated explicitly and systematically. These components include people, infrastructure and environment, all of which are the foundations of city health and sustainability. In this study, we used the analogy of a healthy human and defined a healthy city as a state of complete demographic, infrastructural and environmental well-being, which means that all components are present with integrity and sufficiency and also function effectively, harmoniously and sustainably. Based on this concept, a component-based city health examination framework was constructed and tested in three major cities in China (Beijing, Shanghai and Shenzhen) in both 2010 and 2015. A total of 27 indicators (seven for People, ten for Infrastructure and ten for Environment), each with a health reference value, were chosen and calculated. The fuzzy logic method was selected to perform the evaluation task due to its effectiveness in assessing uncertain and relatively subjective objects. Results showed that all three case study cities failed to meet the healthy condition in both years. Shenzhen was, relatively, the healthiest city among the three in 2015 and had the highest health score in Infrastructure and Environment. Shanghai possessed the highest score in People in both years. Additionally, five indicators with the largest potential for improvement were also identified for each city. This component-based city health evaluation model can be applied to better inform urban planning policies and potentially improve the quality of life in cities in the future.