为探究易贡湖流域地表水水化学特征及其控制因素，以藏东南易贡湖流域为研究对象，采集了26组地表水样，绘制了水样点主要离子线性变化趋势图、Gibbs图及Piper三线图等，运用相关分析、线性趋势分析、数理统计和离子比等方法。分析了研究区地表水主要离子特征及其控制因素，揭示了研究区地表水水中的主要物质来源。结果显示：易贡湖流域地表水阳离子主要为Ca²⁺、Mg²⁺，K⁺和Na⁺含量较低，4种阳离子的含量关系为：Ca²⁺>Mg²⁺>Na⁺>K⁺，阴离子主要为 \mathrm{H} \mathrm{C} {\mathrm{O}}_3^{-}、 \mathrm{S} {\mathrm{O}}_4^{2-}和Cl^-， \mathrm{N} {\mathrm{O}}_3^{-}和F^-含量较低，阴离子含量关系为： \mathrm{H} \mathrm{C} {\mathrm{O}}_3^{-}> \mathrm{S} {\mathrm{O}}_4^{2-}>Cl^-> \mathrm{N} {\mathrm{O}}_3^{-}>F^-，H₂SiO₃浓度值变化平稳，围绕6.9 mg·L^-1上下波动变化，pH值沿程变化平稳，在7.84~8.37之间，水体属于弱碱性。Ca²⁺、Mg²⁺和 \mathrm{H} \mathrm{C} {\mathrm{O}}_3^{-}是构成易贡湖流域地表水中的3种主要离子，水化学类型以HCO₃-Ca·Mg或HCO₃-Ca型为主。岩石溶滤作用是主要控制因素，阳离子交替吸附作用和蒸发浓缩作用均相当微弱，人为活动影响十分有限。

This study examines the hydrochemical characteristics and controlling factors of surface water in the Yigong Lake Basin, southeast Tibet, through the collection of 26 groups of surface water samples. Linear trend diagrams, Gibbs diagrams, and Piper diagrams of the main ions in the water sample points were drawn. Moreover, correlation analysis, linear trend analysis, mathematical statistics, and ion ratio were used to analyze the surface water’s main ion characteristics and controlling factors in the study area, unveiling its material sources. The results show that the predominant cations in the Yigong Lake Basin surface area were Ca²⁺ and Mg²⁺, while K⁺ and Na⁺ levels were relatively low. The hierarchy of cation content was Ca²⁺ > Mg²⁺ > Na⁺ > K⁺. Among anions, \mathrm{H} \mathrm{C} {\mathrm{O}}_3^{-} , \mathrm{S} {\mathrm{O}}_4^{2-} ,and Cl^- dominated, with relatively low levels of \mathrm{N} {\mathrm{O}}_3^{-} and F^-. The hierarchy of anion content was \mathrm{H} \mathrm{C} {\mathrm{O}}_3^{-}> \mathrm{S} {\mathrm{O}}_4^{2-}>Cl^- > \mathrm{N} {\mathrm{O}}_3^{-}>F^-, and the concentration value of H₂SiO₃ maintained a steady fluctuation around 6.9 mg·L^-1. The pH value consistently ranged between 7.84 and 8.37, indicating weak alkalinity. The three main ions in the surface water of the Yigong Lake Basin were Ca²⁺, Mg²⁺, and \mathrm{H} \mathrm{C} {\mathrm{O}}_3^{-}, and the hydrochemical types were mainly HCO₃-Ca·Mg or HCO₃-Ca. Rock leaching was the primary controlling factor, with minimal influence from cation-alternating adsorption, evaporation, or human activities on water concentration.