Coupling Coordination of Urbanization and Eco-Environmental Quality in Five Chinese Urban Agglomerations Based on Pericoupling and Distance-Decay Spatial Interaction Framework

Rapid urbanization in China has intensified pressure on regional ecological systems, necessitating quantitative assessment of urbanization–eco-environment interactions. This study investigates the coupling coordination between urbanization and eco-environmental quality (EQ) in five major Chinese urban agglomerations from 2001 to 2024 using multi-source remote sensing data. An improved eco-environmental index (AMEI) and an urbanization index (MCNLI) were constructed, and a dual peri-telecoupling-inspired coordination model (DPTCM) was developed to capture both local interactions and distance-decayed cross-regional spillover effects. Results show that, across the five urban agglomerations, the average urbanization level increased from 0.24 to 0.33 (38.9%), while EQ declined from 0.44 to 0.39 (11.3%). The Pearl River Delta exhibited an opposite trend, with EQ increasing by 18.7%. Despite this ecological decline, the overall coupling coordination degree increased from 0.55 to 0.65 (19.3%). Spatially, higher coordination levels are concentrated in the Pearl River Delta and Yangtze River Delta, whereas the Central Yangtze River and Chengdu–Chongqing regions exhibit relatively lower coordination. Although ecological conditions have generally declined, the coordination between urbanization and the eco-environment has improved across regions, with significant spatial heterogeneity. This study provides a comprehensive quantitative framework for assessing urban-ecological interactions and offers insights for guiding sustainable urban development in densely populated regions.