Dr. Pradeep Kumar Srivastava
Suresh Gyan Vihar University, Jaipur, Rajasthan.
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Subject: Water Resources Engineering
Lecture No: 21
Keywords: stream bed., suspended load , wash load, downstream fining, , selective transport, rounding. sediment transportation, hydraulic geometry, mass flow rate, erosion

Description:
The various objectives of river training are (i) To guide the axis of flow at ordinary and low stages and safe passage of floods without overtopping the banks. (ii) To protect the banks from erosion and generally improve their alignment by stabilizing the river channel, (iii) To train the river flow along a safe course, thereby avoiding damage by flooding or erosion of valuable lands, habitation, crops, factories, etc., (iv) To prevent outflanking of a bridge, barrage or weir by directing the flow in a defined stretch of the river, (v) To prevent river from changing its course, (vi) To confine a river channel which has become too wide by swinging from side to side and to reclaim the land from river bed, (vii) To check certain devastations like that of flash torrents, (viii) To trap bed load in areas of superfluous width, (ix) To transport efficiently bed load and suspended sediment load, (x) To provide sufficient depth of flow for safe navigation, (xi) To establish channel boundaries where braiding has created too wide a section divided into small channels separated by island, and (xiii) To correct disorderly banks or flow conditions. River training is an age-old practice resulting in incessant development and application of human ingenuity to correct vagaries of the rivers. It requires deep and precise study of river mechanism and behavior discussed heretofore. River training has assumed considerable significance in India due to huge annual recurring damage caused by the floods; 80 per cent of which accounts for loss of crops. River training, in its broad aspects, covers all engineering works constructed on a river to guide and confine the flow to the river channel, and to control and regulate the river bed configuration for effective and safe movement of floods and river sediments. In essence, river training envisages training and stabilizing a river within a suitable waterway and along a certain alignment for a variety of purposes. River training works involve large outlays and it is essential to select the type of the training work and materials of construction so as to make optimum utilization of funds, and effective and economical utilization of the available construction materials.

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