<P> The hydrology of the Brahmaputra River is characterized by its significant rates of sediment discharge, the large and variable flows, along with its rapid channel aggradations and accelerated rates of basin denudation . Over time, the deepening of the Bengal Basin caused by erosion will results in the increase in hydraulic radius, and hence allowing for the huge accumulation of sediments fed from the Himalayan erosion by efficient sediment transportation . The thickness of the sediment accumulated above the Precambrian basement has increased over the years from a few hundred meters to over 18 km in the Bengal fore - deep to the south . The ongoing subsidence of the Bengal Basin and the high rate of Himalayan uplift continues to contribute to the large water and sediment discharges of fine sand and silt, with 1% clay, in the Brahmaputra River . </P> <P> Climatic change plays a crucial role in affecting the basin hydrology . Throughout the year, there is a significant rise in hydrograph, with a broad peak between July and September . The Brahmaputra River experiences two high - water seasons, one in early summer caused by snow melt in the mountains, and one in late summer caused by runoff from monsoon rains . The river flow is strongly influenced by snow and ice melting of the glaciers, which are located mainly on the eastern Himalaya regions in the upstream parts of the basin . The snow and glacier melt contribution to the total annual runoff is about 27%, while the annual rainfall contributes to about 1.9 m and 19,830 m3 / s of discharge . The highest recorded daily discharge in the Brahmaputra at Pandu was 72,726 m3 / s August 1962 while the lowest was 1,757 m3 / s in February 1968 . The increased rates of snow and glacial melt are likely to increase summer flows in some river systems for a few decades, followed by a reduction in flow as the glaciers disappear and snowfall diminishes . This is particularly true for the dry season when water availability is crucial for the irrigation systems . </P> <P> The course of the Brahmaputra River has changed drastically in the past two and a half centuries, moving its river course westwards for a distance of about 80 km (50 mi), leaving its old river course, appropriately named the old Brahmaputra river, behind . In the past, the floodplain of the old river course had soils which were more properly formed compared to graded sediments on the operating Jamuna river . This change of river course resulted in modifications to the soil - forming process, which include acidification, breakdown of clays and buildup of organic matter, with the soils showing an increasing amount of biotic homogenization, mottling, coating arounds Peds and maturing soil arrangement, shape and pattern . In the future, the consequences of local ground subsidence coupled with flood prevention propositions, for instance localised breakwaters, that increase flood - plain water depths outside the water breakers, may alter the water levels of the floodplains . Throughout the years, bars, scroll bars and sand dunes are formed at the edge of the flood plain by deposition . The height difference of the channel topography is often not more than 1m - 2m . Furthermore, flooding over history of the river has caused the formation of river levees due to deposition from overbank flow . The height difference between the levee top and the surrounding floodplains is typically 1m along small channels and 2 - 3m along major channels . Crevasse splay, a sedimentary fluvial deposit which forms when a stream breaks its natural or artificial levees and deposits sediment on a floodplain, are often formed due to a breach in levee, forming a lobe of sediments which progrades onto the adjacent floodplain . Lastly, flood basins are often formed between the levees of adjacent rivers . </P> <P> During the monsoon season (June--October), floods are a very common occurrence . Deforestation in the Brahmaputra watershed has resulted in increased siltation levels, flash floods, and soil erosion in critical downstream habitat, such as the Kaziranga National Park in middle Assam . Occasionally, massive flooding causes huge losses to crops, life, and property . Periodic flooding is a natural phenomenon which is ecologically important because it helps maintain the lowland grasslands and associated wildlife . Periodic floods also deposit fresh alluvium, replenishing the fertile soil of the Brahmaputra River Valley . Thus flooding, agriculture, and agricultural practices are closely connected . </P>

What is brahmaputra called in tibet and bangladesh