This paper investigates the impact of land use/cover type changes in the Haideigou open-pit coal mine on the evolution of the landscape patterns and ecological and environmental quality in the mine area, based on medium- and high-resolution remote sensing images in 2006, 2011, 2016, and 2021 using ArcGIS 10.5, Fragstats 4.2, and the Google Earth Engine platform. The results show that: (1) From 2006 to 2021, the area of cropland and waste dumps in the Heidaigou mining area changed significantly, the land use shifted in a single direction, and the overall land use change was unbalanced. (2) Through the analysis of landscape indicators, it was shown that the diversity of the landscape patches in the study area increased, connectivity decreased, and the patches became more fragmented. (3) Based on the changes in the mean value of the RSEI over the past 15 years, the ecological environment quality of the mining area deteriorated first and then improved. The quality of the ecological environment in the mining area was significantly affected by human activities. This study provides an important basis for achieving the sustainability and stability of ecological environmental development in mining areas.

In Tibet, water resource has been less studied due to remote and harsh conditions. In this study, hydrochemistry and stable isotopes (δ²H, δ¹⁸O and ⁸⁷Sr/⁸⁶Sr) were employed to investigate the major factors affecting the hydrochemical process of groundwater and surface water in the lower reaches of the Yarlung-Zangbo River, southern Tibet. Groundwater and surface water were weakly alkaline and very soft to moderately hard water. The hydrochemical type of surface water is mainly Ca-HCO₃ (mainstream) and Ca-SO₄-HCO₃ (tributary), while the hydrochemical type of groundwater was mainly Ca-SO₄-HCO₃. Multivariate statistical analysis and Gibbs analysis proposed hydrochemical components were dominated by water-rock interaction. Ion ratio, saturation index, and Sr isotope revealed calcite dissolution and silicate weathering with local sulfide oxidation were involved in water–rock interaction. D-O isotopes indicated the recharge source was mainly derived from atmosphere precipitation. The entropy-weighted water quality index indicated surface water and groundwater reach the standard of drinking purpose in the lower reaches of the Yarlung-Zangbo River. The hydrochemical type varied regularly along the Yarlung-Zangbo River. The dissolution of carbonate rocks and local silicate weather and evaporate dissolution are the primary hydrochemical process along the Yarlung-Zangbo River. This study would provide a preliminary insight for hydrochemical process in the Yarlung-Zangbo River.