基于雅鲁藏布江流域枯水期干支流地表径流、泉水、地下水以及降水样品, 对主要离子、pH 、TDS 和 CO2 消耗 进行分析, 研究枯水期水化学特征及成因, 并分析流域化学风化速率及 CO2 消耗通量。结果表明: 流域水体总体呈 现弱碱性, 地表径流 T DS 均值约为世界河流的 21 3 倍, 和长江流域相似, 但远低于黄河流域。岩石风化是地表径流 离子来源的主要影响因素。碳酸盐风化、硅酸盐风化和蒸发盐风化分别占离子来源的 461 3% 、281 6% 和 211 3% , 碳 酸盐风化速率和硅酸盐风化速率分别为 11 43 t/ ( km2 # a) 和 11 11 t/ ( km2 # a) , 对应的 CO2 消耗速率为 01 80 @ 105 mo l/ ( km2 # a) 和 01 55@ 105 mo l/ ( km2 # a) , 枯水期化学风化速率和 CO2 消耗速率较小。

Based o n t he surface runoff, spring w ater, g r oundwater, and pr ecipitatio n samples obtained in the dry seaso n from the main t ributaries o f Yarlung Zangbo River basin, the main ions, pH , TDS and CO2 co nsumpt ion wer e analyzed. The hy dr ochemi2 cal char act eristics and causes w ere studied. T he chemical w eathering r ate and CO2 co nsumption flux in the basin w ere also ana2 lyzed. The results indicated that t he basin water w as mild alkaline as a who le. The mean T DS of surface runoff was appro x i2 mately 21 3 times compared t o the wo rldcs rivers. It w as similar to the Yang tze River Basin but far below the Yellow River Ba2 sin. Rock weathering was the main facto r affecting the ion sour ce of surface runoff. Carbonate weathering , silicate w eathering and evapor at e w eathering acco unted for 461 3% , 281 6% , and 211 3% o f the io n so ur ces, respect ively. The carbonate w eathering rate and silicate rat es w ere 11 43 t/ ( km2. a) , and 11 11 t/ ( km2 . a) , the correspo nding CO2 co nsumpt ion r ates wer e 01 80 @ 105 mol/ ( km2 . a) and 01 55 @ 105 mol/ ( km2 . a) , w hile the chemical w eathering and CO2 consumptio n r ates w ere found lower in dry season.

国家自然科学基金( 41807161; 51679089)