Brahmaputra River System
The Brahmaputra (/ˌbrɑːməˈpʊtrə/), also known as the Yarlung Tsangpo in Tibet, the Siang/Dihang River in Arunachal Pradesh, and Luit in Assamese, is a trans-boundary river which flows through Tibet, India, and Bangladesh. It is the 9th largest river in the world by discharge, and the 15th longest.
From Sanskrit ब्रह्मपुत्र (brahmaputra, “son of Brahma”)
1. Sustainable solutions for mitigation of flood and riverbank erosion in the Brahmaputra River require a holistic approach involving integrated river management planning and design.
2. All issues and challenges pertinent to braided behavior, channel migration, horizontal instability, and high sediment load carried by high water discharge are to be addressed through mathematical hydrodynamic, river bed and bank erosion, and sediment transport model studies and satellite imagery data based approaches.
3. Geomorphic assessment, hydrological data, hydraulic data, geotechnical investigation and GPS survey (topography, cross-section etc,) are to be integrated using Geographical Information System (GIS). The selection of appropriate technology will depend on the collected data for the sites. In addition, watershed or catchment area management impact in the Brahmaputra is to be integrated in the study.
4. Based on all available information, it appears that there are at least four major geological channel control points along the Brahmaputra in Assam: (1) Bessamora in Majuli, (2) Tezpur, (3) Pandu near Guwahati, and (4) Jogighopa near Goalpara. These points are holding the river around the present alignment. As such, the sustainable solutions will includues
Channelization of the river starting from the four identified geological control points.
Determination of other control points or establishment of two channel formations north of Dibrugarh.
Revisit all flood prone areas along the Brahmaputra and generate flood prone maps with priorities.
Alternative measures such as new embankment, raising, repairing and/or stabilizing existing embankments, and use of new materials such geo-tubes should be investigated and considered.
5. Design of flood control embankment should consider:
Efforts (using satellite imagery and mathematical modelling) to predict future behaviour with respect to shifting and erosion,
Provision of erosion protection to deflect or forestall river attack and associated embankment failure,
River channel improvement if possible by its cross-sectional area, re-grading its banks slopes, and covering those with vegetation or revetments
Pumping: There will be some area where pumping offers the only possibility for timely disposal of flood water