[Driving Factors and Coordinated Zoning of the Carbon Budget Pattern in the Bohai Rim Urban Agglomeration]

As a pivotal economic development zone in northern China， the Bohai Rim urban agglomeration holds significant strategic importance for regional low-carbon synergistic development through clarifying the evolution of its carbon budget. Utilizing EDGAR datasets and net ecosystem productivity （NEP） data， this study reveals the carbon budget patterns at the municipal scale within the Bohai Rim region from 2000 to 2023. It calculates the economic contribution coefficient of carbon emissions （ECC） and ecological support capacity coefficient of carbon （ESC） for the years 2001， 2012， and 2023 to assess energy utilization efficiency and carbon sink capacity. Furthermore， the optimal parameters-based Geodetector （OPGD） is employed to identify key driving factors behind spatial differentiation in carbon balance. Finally， integrated with major function-oriented zones in territorial spatial planning， the study proposes optimized carbon balance zoning at the municipal scale across the Bohai Rim urban agglomeration. The results show that： ① From 2000 to 2023， the carbon emissions of the Bohai Rim Urban Agglomeration presented a distribution pattern of being higher in the middle and lower in the surrounding areas， while the carbon absorption showed a spatial distribution feature of being higher in the north and lower in the south. The OPGD results indicated that per capita GDP （X₅） and population density （X₆） had significant single-factor explanatory power for the carbon balance， and the interaction factors had a significantly stronger influence on the carbon balance compared to that of individual factors. ② ECC exhibited a trend of rising first and then falling and presented a spatial distribution pattern of scattered high-value areas and concentrated low-value areas， while ESC showed a spatial distribution feature of being higher in the north and lower in the south. ③ The carbon balance zoning based on ECC， ESC， and the main functional zoning showed that the economic development area-key development area covered a wide area， while the carbon sink development area-optimized development area was concentrated in cities such as Beijing and Tianjin， and the comprehensive optimization area-key development area had an increasing number of city regions. The research results provide theoretical support and decision-making basis for the formulation of low-carbon policies in the Bohai Rim Urban Agglomeration.