[Spatio-temporal Evolution and Driving Factors of Ecological Quality in the "Hohhot-Baotou-Ordos" Urban...

The study of the spatio-temporal changes in ecological environment quality and its driving factors in the "Hohhot-Baotou-Ordos" urban agglomeration is significant for regional ecological environment protection and promoting sustainable development. Based on Google Earth Engine (GEE), the remote sensing ecological index (RSEI) for the "Hohhot-Baotou-Ordos" urban agglomeration from 2003 to 2022 is calculated. Trend analysis, spatial autocorrelation analysis, and semivariance analysis are employed to explore the spatiotemporal evolution of RSEI, while appropriate spatial scales are selected to examine spatial heterogeneity. The human activity intensity (HAI) is calculated, and geographic detectors and correlation analysis are used to reveal the driving factors of the spatial differentiation of RSEI. The results showed that: ① Over the 20-year period, the ecological environment quality of the study area has generally degraded, with a distribution pattern of higher quality in the central region and lower quality in the western and northern regions. The RSEI mean value decreased from 0.34 to 0.31, with degraded areas accounting for approximately 53.65%. ② A grid size of 900 m×900 m can effectively study the weakening scale effect in the study area. Over the 20 years, Moran's I index decreased from 0.88 to 0.68, the ratio of cobalt C_O/(C+C_O) increased to 0.34, and the spatial heterogeneity of RSEI distribution significantly increased. ③ HAI, land surface temperature (Lst), and precipitation (Pre) were the main driving factors of spatial differentiation. Interactions between these factors showed significant bi-factor enhancement and nonlinear enhancement, with the interaction between HAI and other factors explaining the most variation. ④ The impact of human activities was concentrated in urban agglomeration areas, with 17.33% of regions showing a significant positive correlation between HAI and RSEI and 10.46% showing a significant negative correlation. The findings provide scientific support for sustainable development and human activity regulation in the "Hohhot-Baotou-Ordos" urban agglomeration.