Dissolved aluminum and silica in the Changjiang (Yangtze River): Impact of weathering in subcontinental scale

摘要: [1] Water samples were collected from the river mouth upstream over a distance of 3500–4000 km in Changjiang (Yangtze River) and its 15 tributaries April–May 1997, at Nantong close to 1996–1998. Dissolved Al Si determined compared with data water flow, total suspended matter, alkalinity. Data obtained show that dissolved illustrates rather uniform distribution toward mouth, broad increasing higher alkalinity ratio has been found. The plots Al:Si against specific runoff sediment yields reveal different weathering mechanisms involved tributaries. At Nantong, concentration is considerably stable relative important seasonal variations discharge load. Acidification bulk riverine releases an amount can be one order magnitude than natural concentrations, indicating potential remobilization by acid deposition and/or waste drainage. Compared other world rivers, low similar those primitive systems.