[Dynamic Evaluation Map and Driving Force Analysis of Ecological Environment Quality on the Southern Slope of Qilian Mountains Based on GEE].

Climate change and anthropogenic activities pose a formidable challenge to regional ecological systems， necessitating robust research frameworks to assess ecological environment quality. The dynamic， quantitative evaluation of such quality serves as a cornerstone for strategizing ecological protection measures and fostering ecological civilization. Leveraging MODIS data spanning from 2001 to 2020， this study harnesses the power of the Google Earth Engine （GEE） platform and the remote sensing ecological index （RSEI） as a pivotal evaluation tool to conduct a comprehensive appraisal of the ecological health of the southern slope of the Qilian Mountains. Employing Sen's trend analysis and the Mann-Kendall （M-K） test， we delineate the spatial evolution patterns of the RSEI， offering insights into its temporal dynamics. Furthermore， by integrating geological information mapping with Pearson correlation analysis， we delve into the intricate interplay between natural environmental factors and human activities that shape RSEI variations. Our findings revealed several salient points： Firstly， the ecological quality of the southern slope of the Qilian Mountains exhibited pronounced spatial heterogeneity， with the vicinities of the Datong， Heihe， Beida， and Babao River basins boasting exceptional ecological quality， in contrast to the relatively degraded conditions in higher-elevation areas. Temporally， from 2001 to 2020， the RSEI index fluctuated within a range of 0.62 to 0.70， signifying an overall enhancement in ecological environment quality， a testament to the vigorous implementation of ecological restoration projects in recent years. The average annual RSEI value stood at 0.66， indicative of stability amidst modest fluctuations， though peripheral regions experienced notable RSEI volatility due to climatic shifts. Encouragingly， over 80% of the southern slope experienced ecological improvement， with a mere 11% experiencing slight degradation， suggesting a promising trajectory for future ecological enhancement. However， caution must be exercised against the risk of unsustainable improvement. Temperature， precipitation， and human interventions all contributed to RSEI variations， with temperature exerting a more pronounced influence than precipitation. Notably， human activities correlated positively with RSEI， underscoring the significance of human stewardship in ecological improvement. This research fills a critical gap in the long-term， dynamic monitoring of the ecological environment on the southern slope of the Qilian Mountains， providing a robust foundation for targeted ecological governance and fostering green development initiatives in this vital region.