Spatial-Temporal Evolution Patterns and Obstacle Factors of Urban–Rural “Economy–Society–Ecology” Coordination in the Yangtze River Delta

Background: In the context of sustainable development, urban–rural integration is not solely focused on high economic growth but has been expanded to a wider range of social and ecological fields. Objectives: To analyze the spatial and temporal evolution of the coupling coordination level of urban–rural economic, social and ecological integration subsystems in the Yangtze River Delta and to explore its main obstacles, in order to provide countermeasures to promote the sustainable development of urban and rural areas. Methods: Panel data of 16 cities in the core area of the Yangtze River Delta from 2005 to 2020 were selected, and the entropy method was used to calculate the comprehensive development level of each subsystem, based on which the coupling coordination degree was measured by the coupling coordination model, and the obstacle degree of each indicator was obtained by the obstacle degree model. Outcomes: The urban–rural integration level kept a steady rise, and the “economy–society–ecology” coordination level transformed from borderline imbalances to moderate coordination. The high-value areas presented an initial “Π” shape distribution that later turned into a “>” shape, while the backward areas were primarily located at both ends of the north and south. The key obstacle factors included per capita GDP, population urbanization rate, urban and rural basic pension insurance coverage, faculty–student ratio in urban and rural primary and middle schools, per capita park green land, road network density and fertilizer application per unit area of sown. Recommendations: The systematic coordination of urban–rural integration should be promoted according to local conditions, with emphasis on broadening urban–rural communication channels, promoting the equalization of urban–rural public services and establishing the urban–rural collaborative mechanism for environmental maintenance.