Drainage basin weathering and major element transport of two large Chinese rivers (Huanghe and Changjiang)

Abstract

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...

Spatial and temporal analysis of water chemistry records (1958–2000) in the Huanghe (Yellow River) basin

“…Although their data have been widely cited, they only sampled at one station (Sanmenxia along the main channel) at a single sampling event. Zhang et al [1990] discussed to some detail the weathering process in the Huanghe basin, but the water chemistry data reported were for the estuary only. Zhang et al [1995] sampled 10 mainchannel stations along the Huanghe and analyzed for major elements, as well as stable oxygen isotopes.…”

Hydrogeochemical processes, mixing and isotope tracing in hard rock aquifers and surface waters from the Subarnarekha River Basin, (east Singhbhum District, Jharkhand State, India)

“…mainly the weathering of rocks and soils, atmospheric inputs and anthropogenic disturbances (Drever, 1988). Detailed studies focused on the exogenic cycle of the elements were carried out on large-to medium-size river systems, including the Amazon, the Congo, the Ganga-Brahmaputra, the Indus, the Huanghe… (Sarin et al, 1989;Négrel et al, 1993;Pande et al, 1994;Gaillardet et al, 1997;Zhang et al, 1990). For small catchments, the application of geochemical tools may provide constraints on runoff, on the natural and anthropogenic end-members and on their respective contributions (Ben Othmann et al, 1997;Négrel and Deschamps, 1996), 4…”

Environmental Integrity of the Tamiraparani River Basin, South India

“…Downstream variations of major ions have been reported for a number of other rivers (Subramanian 1983;Gupta and Subramanian 1994;Zhang 1995;Datta and Subramanian 1998). Though an abundance order of H 4 SO 4 > HCO 3 + Cl + SO 4 anions is reported for rivers that drain areas where intense silicate weathering is prevalent, (Zhang et al 1990), the Tamiraparani River do not show such a trend. On the other hand it has a characteristic feature of predominance in Ca 2+ and Mg 2+ cations and high (Ca + Mg): (Na + K) ratio, typical of river basins that drain regions where carbonate weathering prevail.…”