Long-term records show high over the drainage basins is still not clear, concentrations of dissolved major elements in the especially for the rivers draining in areas with Changjiang (Yangtze River) and the Huanghe (Yellow River}. The Huanghe drainage basin is characterized by intense weathering and erosion of carbonates and evaporites, while weathering and erosion of carbonates and silicates over the drainage basin is the main source of major elements in the Changjiang. The rock/soil complex rock/soil compositions and/or different climate zones. The Changjiang (Yangtze River} and Huanghe (Yellow River} represent a drainage basin area of 1.8x106 km z and 0.75x106 km z, respectively (Figure 1}. After the Amazon, Zaire, and Orinoco, the Changjiang is the fourth largest source of fresh composition and tectonics of the drainage basin water to the ocean [Milliman and Meade, 1983; are more important than atmospheric precipitation Milliman et al., 1985]. Annual water and sediment in affecting major element composition of these discharges of the Changjiang average 928.2x109 m 3 two rivers. Compared with other large rivers of and 0.Sx10 lz kg, respectively. The averaged the world, the high suspended sediment and major monthly water discharge of the Changjiang ranges element loads of the Changjiang and Huanghe from 10.0x103 m•/s to 49.0x10 • m3/s at the Datong reveal intense physical and chemical erosion over Hydrographic Station (625 km inland from the the Chinese continent. river mouth), corresponding to a variation of suspended sediment concentration from 0.1 g/L to 1. Introduction 0.8 g/L in the river. Much higher water discharge values (60-70x10 • m•/s) are observed during the The elemental geochemistry in some of the flood period. The Huanghe, long known for its large Chinese river/estuary systems and the high suspended sediment concentration, transports coastal areas has been extensively studied in 43.2x109 m 3 of fresh water and 1.1x10 lz kg of recent years [Hu et al., 1982; Thomas and Martin, suspended sediment annually to the river mouth. 1982; Li et al., 1984; Milliman et al., 1984; The monthly mean water discharge ranges from Edmond et al., 1985; Elbaz-Poulichet et al., 0.5x10 • m3/s to 2.7x103 m3/s at the Lijin 1987; Zhang, et al., 1988], mainly owing to Hydrographic Station (150 km inland from the international cooperation and/or joint study river's mouth), but the water discharge may programs. This compensates partly for the lack of exceed 10.0x103 m3/s in flood periods. The elemental composition data of Chinese river/ocean suspended sediment concentration in the lower systems in the international literature. However, reaches of the Huanghe ranges from 2.8 g/L in most of the studies are restricted to behavior of lower water stage to 45.6 g/L during high water chemical elements in the estuarine and coastal stage, with a mean value of 25.6 g/L. Values of environments and especially to that of trace and 200-250 g/L have been observed during the flood nutrient elements; little attention is paid to periods; it is...
