Spatiotemporal analysis of the coupling and coordination between industrial structure and ecological environment in the Yellow River basin

Based on panel data from 57 prefecture-level cities in the Yellow River basin from 2008 to 2021, this study constructs an evaluation index system to assess the coupling coordination between industrial structure and the ecological environment (hereafter referred to as the “two systems”)． A combined weighting method is used to measure the comprehensive development levels of the two systems, while kernel density estimation (KDE) and spatial Markov chain analysis are employed to examine the spatiotemporal evolution and spatial transition characteristics of the coupling coordination between the two systems． The results show that, firstly, the coupling coordination level exhibits pronounced spatial heterogeneity, with the highest level in the downstream region, followed by the midstream region, and the lowest level in the upstream region． The KDE curves gradually shift to the right over time, indicating an overall improvement in coupling coordination; secondly, the conventional Markov chain results show that the probabilities of cities remaining at their original coupling coordination levels range from 0.564 to 0.859, indicating significant path dependence, and club convergence; and lastly, the spatial Markov chain results reveal a clear spatial spillover effect． When neighboring cities are at a high coupling coordination level, the probability of a local city remaining at a high level reaches 0.956． In addition, cities surrounded by neighbors with higher coordination levels exhibit a greater probability of upward transition． These findings provide quantitative evidence for promoting ecological protection and high-quality development in the Yellow River basin．