Evolution of ecological environment quality in China's inland river basin based on multi-source data and model analysis

The inland rivers under the geographical pattern of the mountain-basin system in the arid areas of China have special ecosystem types and landscape appearances. The inland river basin, represented by the Tarim River, has given birth to different ecosystem types and landscape appearances of river corridors-vegetation or farmland patches-desert matrix patterns. Through multi-source remote sensing(RS) data, geographic element monitoring data, ecological environment statistical survey data, model simulation and other multi-source data, the data verification and normalization are carried out, and the ecological environment quality(EEQ) characteristics are obtained through model operation and analysis.The results show that due to the constraints and influences of the mountain-basin system, precipitation shortage, strong evaporation, and severe drought lead to the widespread salinization of the basin. In addition, the sparse vegetation and the frequent occurrence of sandstorm disasters have led to drastic changes in the spatiotemporal dynamics of desertification. Under the multiple stresses of climate change and the development of man-made water resources and land resources, a series of changes have taken place in the EEQ. The analysis of panchromatic aerial RS images (1959), color aerial RS images (1992), JERS-1 OPS RS images (1995) and MODIS RS images (2023) shows that desert riparian forests show a discontinuous distribution on the north and south sides of the main stream corridor, and the vegetation tends to be degraded from the source area to the upper, middle and lower reaches of the main stream. Since 2000, the water resources allocation project in the basin has alleviated the vulnerability of water resources to spatiotemporal changes, slowed down the degradation trend of EEQ in the basin, and significantly improved the EEQ in some areas.Based on the systematic analysis of multi-source data such as hydrology, soil, climate, vegetation and landscape pattern changes in the basin, combined with the SSP climate scenario model, it is found that the future temperature and precipitation will show an upward trend under the SSP2-4.5 and SSP5-8.5 scenarios. Through the establishment of the ecological risk index (ERI) model, the quantitative evaluation showed that the ERI values of the Aksu River Basin in the headwaters were 0.08 and 0.06 in 1998 and 2023, respectively, indicating that the EEQ was in a stable and improving state in the past 25 years, and the EEQ continued to improve. It is estimated that by 2040, drought and flood disasters in the basin will be further aggravated, and the evolution of EEQ will be complex and uncertain.