[Spatio-temporal Monitoring and Driving Factor Analysis of Eco-environment Quality in the Loess Plateau of Northern...

Located in the core area， the Loess Plateau of Northern Shaanxi is characterized by a sensitive and fragile eco-environment facing a series of ecological challenges such as soil erosion， desertification， and salinization. Therefore， comprehensive and quantitative monitoring and analysis of the spatio-temporal changes and driving factors of eco-environment quality are critically important for regional eco-environment protection. Based on Google Earth Engine （GEE）， and taking the ecological characteristics into account， an adjusted remote sensing ecological index（RSEI_A）was constructed by introducing the composite salinity index （CSI） and desertification difference index （DDI） into the classical remote sensing ecological index （RSEI）. Dynamic monitoring of eco-environment quality in the Loess Plateau of Northern Shaanxi from 2000 to 2020 was carried out. Spatial distribution characteristics and driving factors of eco-environment quality were discussed using spatial autocorrelation analysis and a geo-detector model. The results show that： ① The contribution rate of the first principal component （PC1） of RSEI_A generally exceeded 91%， which can be used to comprehensively reflect the characteristics of each ecological factor and has wide application in regional eco-environment quality evaluation. ② Over the past two decades， the regional eco-environment quality has improved distinctly， showing an increasing trend first， followed by a decline and then an increasing pattern. From 2000 to 2020， the area proportion of very poor and poor quality decreased from 72.83% to 33.41%， respectively， and the proportion of good and excellent quality increased from 15.93% to 37.05%. ③ Improved areas were greater than those of deterioration， and significant improvements accounting for 31.37% were observed particularly from 2000 to 2005. From 2010 to 2015， the most severe degradation occurred with a proportion of 10.14%. Improved areas were concentrated in the central and northeastern parts， whereas degraded areas were located mainly in the west. ④ The spatial distribution of the regional eco-environment quality had a strong and close positive spatial correlation. NDVI outperformed other ecological factors and contributed the most to RSEI_A， while in other factors， precipitation was the most influential one. The results are expected to provide basic information and scientific foundation for the monitoring and protection of regional eco-environment quality.