Nature of Sediment Load in the Ganges-Brahmaputra River Systems in India

Abstract

No generalizations can be made from the existing data about the sediment load transported by the Ganges-Brahmaputra River systems due to wide diurnal, seasonal and annual variations in the sediment-carrying capacity of these rivers. Estimates of the sediment load are highly variable, ranging from 402 to 710 {\texttimes} 106 tonnes/year for the Brahmaputra River and from 403 to 660 {\texttimes} 106 tonnes/year for the Ganges River. Both these rivers carry predominantly coarse silt to sand-size particles. Human impact on the natural processes of sediment erosion and deposition are evident in both river systems although at different levels. Detrital sands and illitic clays dominate the mineral composition of the river loads. In comparison to the global averages, the denudation rates in the Himalayan river system are four-fold higher.