Spatiotemporal Evolution of Coupling Coordination Between Technological Innovation and the Ecological Environment in the Yangtze River Economic Belt and Its Associated Factors: An XGBoost-SHAP Analysis

Against the backdrop of tightening ecological constraints and the accelerating transition toward high-quality development, the coordinated development of technological innovation and the ecological environment has become an important topic in regional sustainability research. Using 111 cities in the Yangtze River Economic Belt from 2013 to 2023 as the study sample, this study applied principal component analysis and a coupling coordination model to measure the coupling coordination degree between technological innovation and the ecological environment. It further employed the XGBoost-SHAP model to investigate the factors associated with their coordinated development. The results showed that: (1) During the study period, both the comprehensive development level of technological innovation and that of the ecological environment level increased, although a pronounced spatial mismatch existed between them. The former exhibited an east-to-west declining gradient, whereas the latter followed a spatial pattern of the middle reaches > upper reaches > lower reaches. (2) The overall coupling coordination level transitioned from the low coordination stage to the primary coordination stage. Significant regional disparities were observed, with the coupling coordination degree decreasing progressively from east to west. (3) The XGBoost-SHAP results indicated that the urbanization level and fiscal autonomy were important factors associated with the coordinated development of technological innovation and the ecological environment. Furthermore, the marginal contributions of the individual factors exhibited complex nonlinear patterns. These findings enhance the understanding of the coordinated development of technological innovation and the ecological environment and provide empirical evidence for differentiated governance and policy design across the Yangtze River Economic Belt.