A Complex Network Method in Criticality Evaluation of Air Quality Standards

In recent years, poor air quality has brought serious threats to public health and sustainable development. The air quality standard is an effective prerequisite to ensure the quality of the air. The citation relationships between air quality standards at a certain time point, which reflect technological development and knowledge transition, form a complex network. In this study, an integrated multi-criteria decision making method is proposed to measure the criticality of standards based on a dynamic citation network model. In particular, the Entropy Weight (EW) method is used to set the weights of each node measurement to avoid subjectiveness, while the TOPSIS method is employed to measure the criticality for each air quality standard. A case study based on the data of 444 of China’s national air quality standards reveals that the complex network method facilitates the identification of critical standards effectively. In addition, we found that there exist some structural problems in China’s air quality standard system: the connectivity between standards is insufficient; critical standards are lacking; and the critical standards change over time following the issue of national policies. Finally, policy suggestions are recommended on strengthening inter-standard citation, attaching importance to the revision of critical standards, and the dynamics of critical standards.