Regional variation of sediment load of Asian rivers flowing into the ocean

Study of Asian major rivers discharge to the ocean reveals variations of their water discharges and sediment loads, and local characteristic of river sediment concentrations. On the basis of this, the Asian rivers can be divided into three regions: Eurasia Arctic, East Asia, Southeast and South Asia Region. The Eurasia Arctic Region is characteristic of the lowest sediment concentration and load, while the East Asia Region is of the highest sediment concentration and higher sediment load, and the Southeast and South Asia Region yields higher sediment concentration and highest sediment load. The sediment loads of these regions are mainly controlled by climate, geomorphology and tectonic activity. The Eurasia Arctic rivers have large basin areas and water discharge, drain low relief which consist of tundra sediment, thus causing the lowest sediment load. The East Asia rivers have small basin areas and lowest water discharges, drain extensive loess plateau, and transport most erodible loess material, which results in highest sediment concentration. The Southeast and South Asia rivers originating from the Tibetan Plateau have large basin areas and the largest water discharges because of the summer monsoon and high rainfall influence, causing the highest sediment load. In Asia, the tectonic motion of the Tibetan Plateau plays an important role. Those large rivers originating from the Tibetan Plateau transport about 50% of the world river sediment load to the ocean annually, forming large estuaries and deltas, consequently exerting a great influence on sedimentation in coastal zones and shelves.