Sustainability-Oriented Spatiotemporal Evolution and Optimization of Socio-Economic-Ecological Systems: Evidence from Inner Mongolia, China

Scientifically evaluating the sustainable coordination between socio-economic development and the ecological environment in Inner Mongolia is essential for reinforcing the northern ecological security barrier and promoting long-term regional sustainability. Using panel data from Inner Mongolia and its nine prefecture-level cities from 2006 to 2022, this study constructs a comprehensive evaluation index system within the Pressure-State-Response (PSR) framework. The entropy-weighted TOPSIS method, the coupling coordination degree model, and the obstacle degree model are jointly applied to examine the spatiotemporal evolution of socio-economic-ecological coordination and to identify key constraints on sustainability. Furthermore, a multi-objective optimization framework based on the NSGA-II algorithm is developed to explore sustainability-oriented regulation pathways. The results indicate that the coupling coordination degree increased from 0.530 to 0.838, representing a growth of 57.9% and reflecting a substantial enhancement in sustainable system interactions. Spatially, a pattern of "core clustering with gradient diffusion" is observed, with the Hohhot-Baotou-Ordos urban agglomeration serving as the primary high-coordination core. Urbanization processes, industrial structure, and pollution emissions are identified as the main obstacles constraining the sustainability of socio-economic development and the ecological environment. The proposed optimization model further provides differentiated regulation strategies to simultaneously promote overall sustainability improvement and balanced regional development.