[Spatial-temporal Changes and Prediction Analysis of Long-term Ecological Environment Quality in the Urban...

Objectively assessing the spatiotemporal evolution and future trends of the ecological environmental quality （EEQ） of the urban agglomeration around Poyang Lake is crucial for achieving a balance between economic development and ecological preservation in the region. Utilizing the Google Earth Engine （GEE） cloud platform， this study filtered MODIS remote sensing images from 2000 to 2020 to extract ecological indicators. The remote sensing ecological index （RSEI） model was constructed via principal component analysis （PCA） to characterize EEQ. The spatiotemporal changes in EEQ within the urban agglomeration around Poyang Lake were analyzed using Theil-Sen slope estimation， coefficient of variation （CV）， and Mann-Kendall tests. Furthermore， the Hurst exponent was introduced to analyze future trends in EEQ. Finally， the CA-Markov model was applied to simulate and predict the EEQ for the year 2030. The results indicate that： The EEQ in the urban agglomeration around Poyang Lake exhibited a fluctuating upward trend from 2000 to 2014， followed by a slight decline thereafter. Over the 21-year period， the overall EEQ remained at a moderate to high level， showing an overall improvement trend. Areas classified as "excellent" were primarily concentrated in the northeastern and western regions， while the central and southern areas were predominantly characterized by "poor" and "fair" grades. The dominant trend of EEQ change was non-significant improvement， covering the largest areal proportion. The centers of gravity for all EEQ grades were located within Nanchang City and its surrounding areas. Over the past five years， these centers exhibited a minor shift predominantly towards the southeast. EEQ demonstrated overall stability， characterized mainly by low and relatively low fluctuations. Future changes are projected to consist primarily of persistent improvement and anti-persistent improvement. By 2030， the EEQ of the urban agglomeration around Poyang Lake is predicted to show some improvement； however， areas classified as "Poor" and "Fair" are expected to remain concentrated in the central， southwestern， and southeastern parts of the study area. This study provides a methodological foundation for rapidly and accurately evaluating regional EEQ， investigating its long-term dynamics， and forecasting its future trajectory. It is essential for reconciling regional development with the natural environment.