An analysis framework for the ecological security of urban agglomeration: A case study of the Beijing-Tianjin-Hebei urban agglomeration

Abstract The ecological security (ES) of urban agglomeration (UA) is an important guarantee and necessary condition for the sustainable development of the region and the country. Based on ecological system theory, this study established a new ES analysis framework for UA; a DPSIR-DEA model was built to evaluate ES from the perspective of system coordination, and Geodetector was used to explore the internal mechanism of the ES system. Taking the Beijing-Tianjin-Hebei urban agglomeration (BTH) as the empirical study area, the results showed that the ES of the BTH was generally insecure during 2005-2018, and it experienced a process in which it first improved, then declined, and finally recovered gradually. The spatial differentiation in the north-south, where the counties in the north have a better ES status than the southern counties, was further aggravated. The spatial autocorrelation analysis indicated that the spatial distribution of ES in BTH has a certain degree of aggregation, and the homogeneity of aggregation is enhanced. The main dominant factors affecting the ES in 2018 included the population density, proportion of construction land, ESV, PM2.5, fertilizer pollution and irrigation area ratio, and the interaction between factors was strengthened. Moreover, the results proved that human production and life play a leading role in the ES maintenance. The study also constructed the driving mechanism of ES and offered suggestions for the ES improvement of the BTH.