Evaluating Sustainable Development in the Middle and Lower Reaches of the Yellow River Basin Using Multiple Data Sources

The Yellow River Basin is an important area in China’s overall development, especially the middle and lower reaches of this river which are vital for the development of the entire basin. Therefore, it is critical to scientifically evaluate the sustainable development of the ecological environment and the social economy in these reaches of the Yellow River Basin. In this study, the level of the coordinated and sustainable development of the ecology and social economy was quantitatively analyzed based on the improved remote sensing ecological index (IRSEI) and development space social and economic curve (DSSEC). The analysis process is as follows. First, Landsat 8 data were used to invert the surface wetness index (WET), normalized difference building and soil index (NDBSI), land surface temperature index (LST), and kernel normalized difference vegetation index (kNDVI). Then, the IRSEI was constructed. Combining principal component analysis (PCA) and particle swarm optimization (PSO) random forest algorithm, an ecological quality evaluation model was established to evaluate the ecological environment in the middle and lower reaches of the Yellow River Basin. The dynamic temporal and spatial evolutions of the ecological environment quality and ecological sustainability were determined. Second, the relationship between the development space and two key social economy processes was quantitatively determined using the DSSEC index, in which the coefficients reflect the basic intensity and concentration of socioeconomic activities, enabling the analysis of the region’s socioeconomic sustainability. Third, the level of coordinated and sustainable ecological and socioeconomic development and its influencing factors were studied using a coupling coordination degree model and a geographical detector. The results showed that the IRSEI in the study area gradually increased from 0.392 in 2014 to 0.612 in 2020, and the ecological quality level in most areas was moderate to good. The social and economic development in the middle and lower reaches of the Yellow River Basin had regional urban centers as the core, indicating the need to emphasize the sustainable development of the central area in planning and development strategies to promote coordinated and balanced development. From 2014 to 2020, we identified an overall trend of linear growth, and the degree of coordination gradually transitioned from moderate imbalance to moderate coordination, showing a trend of increasing sustainable development. The degree of water resource development, industrial structure, and level of urbanization are the main factors driving the coordinated and sustainable development of the ecology and social economy in the middle and lower reaches of the Yellow River Basin.