Study on the Optimization Approach of Regional Air Quality Monitoring Network
|School||South China University of Technology|
|Keywords||Regional air quality monitoring network Multi-object Synthetic evaluation concentrations Cluster analysis Air quality model Maximum approximately degree Fuzzy expert assessment|
In recent years, China’s key city clusters like Yangtze River Delta, Pearl River Delta and Beijing-Tianjin-Hebei are facing serious regional air pollutions with the characteristics of coal combustion-based primary pollution and photochemical pollution coexistence. The current air quality monitoring network mainly considering urban scale and conventional pollutants can not meet the needs for monitoring and studying the complex regional air pollution..Establishing a regional air quality monitoring network (RAQMN) is a urgently issue needed to be addressed for regional air pollution control and air quality management in China. Based upon the unique regional complex pollution characteristics and the needs for managing regional air quality in China, this study established a methodological framework for optimization of site locating for the RAQMN in China. This framework was applied to the regional monitoring network site optimization in the Pearl River Delta region for assessing its feasibility and operability. Main research work are as follows:First of all, on the basis of analying domestic and foreign work regarding air quality monitoring network site location optimization, and considering the current air monitoring network status and regional air pollution characteristics, the feasibility of different optimization methods used in China was discussed, and, the basic principles of RAQMN site locating were proposed. A methodological framework for regional air quality monitoring network site optimization with the use of maximum approximately degree including multi-objective optimization approach, cluster analysis, and fuzzy expert assessment method was established. The idea is to, first, use multi-objective optimization or cluster analysis methods, to obtain a preliminary site location layout, and then use fuzzy expert assessment method to adjust monitoring site locations.Second, the methodological framework proposed in this thesis was applied to the optimization of the PRD. PRD regional air monitoring network site location as a case study to discuss the impact of different optimization methods, objective functions, combination of different target pollutants on the site locations, and the feasiblitity of the framework applied in China was discussed, and suggestions for future work were made.The results show that: (1) The optimizal site locations of RAQMN are closely related to the objectives of the monitoring network, determing the objectives of the RAQMN is the basis of establishing the objective functions and constraints, and selecting the target pollutants for site optimization. (2) For the target pollutants selection of the RAQMN design, only considering the primary pollutants or regional characteristics pollutants is limited, both regional characteristics pollutants and primary pollutants are needed for regional air monitoring network design. (3) In the multi-objective optimization, using high concentration maximum as the optimization objective is not reasonable due to its potential weakness assembling monitoring sites into the grid cell with high target pollutant concentrations, leading to, poor spatial representation and coverages. (4) Further researches are needed for using weighted synthetic evaluation concentrations since the optimal site location results are largely influenced by the weight of different pollutant concentrations. (5) whether using mathematical approach such as multi-objective optimization or statistical methods such as cluster analysis, have some limitations, additional work for adjusting site locations with the help of fuzzy expert evaluation method is necessary.