A comprehensive assessment of urban greenspace accessibility and supply-demand characteristics in Beijing

Urban green spaces serve as critical providers of ecosystem services and play an essential role in promoting residents' physical and psychological well-being. Rapid urbanization, however, has exacerbated inequities in green space distribution. This study develops an urban greenspace accessibility model for Beijing by integrating multidimensional factors (population density, topographic constraints, and vegetation quality), quantifying Greenspace Usage Intensity (GUI), and analyzing supply-demand dynamics. Key findings reveal that: (1) Of Beijing's total greenspace (1,075,485 ha), only 538,346.3 ha (50%) are accessible, with ecological redlines reducing accessibility by 33.9%; (2) Spatial equilibrium in greenspace distribution does not ensure functional equity in service provision; (3) Disparities in vegetation quality (measured by NDVI) amplify supply inequities, as evidenced by a GUQI (Greenspace Usage and Quality Index) Gini coefficient of 0.81; (4) Peri-urban zones emerge as priority areas requiring enhanced greenspace provision due to elevated resident demand. The proposed model advances methodological frameworks for assessing urban greenspace allocation, while the findings contribute to theoretical understandings of environmental justice and optimal resource distribution in metropolitan regions.