Spatiotemporal pattern analysis of PM2.5 and the driving factors in the middle Yellow River urban agglomerations

During the development of the Middle Yellow River Urban Agglomerations (Central Plains Urban Agglomeration (CPUA), Guanzhong Plains Urban Agglomeration (GPUA), Jinzhong Urban Agglomeration (JZUA)), “urban disease” was prominent, and the concentrations of PM2.5 in many cities in the region were ultra-high, resulting in serious air pollution. Taking into account the hysteresis of PM2.5 pollution, from the point of view of socioeconomic, this paper uses the geographically and temporally weighted regression (GTWR) model and the latest available data of PM2.5 concentration and socio-economic factors of the urban agglomeration in the Middle Yellow River from 2015 to 2018 to explore the spatiotemporal heterogeneity of PM2.5 concentrations and the driving factors. The results indicate that: (1) The spatiotemporal distribution profiles of PM2.5 concentrations in urban agglomerations in the middle Yellow River have certain regularities. It reveals a U-shaped pattern in each year, and the seasonal changes show the spring and winter are high and summer and autumn are low. (2) PM2.5 in the Middle Yellow River Urban Agglomerations has obvious spatial agglomeration characteristics. (3) There are obvious spatiotemporal heterogeneity in the change of the intensity and direction of each driving factor. Based on the above analysis, three suggestions were put forward: (1) Increase the proportion of new energy in heating. (2) Establish regional joint prevention and control and long-term incentive mechanisms. (3) Different urban agglomerations should formulate differentiated PM2.5 emission reduction strategies.