PLANNING FOR RIVER TRAINING MEASURES
The training measures are planned with due regard to the limitations imposed by the type of river. The various steps involved are as follows:
1. Alignment. Alignment of training work is generally based on the layout and number of training structures involved. A better way to arrive at radius of curve is to study to photographs of alignment of a stable stretch of river on a similar grade and soil conditions in the vicinity of the erosion site and from this stable section measure the radius of curves. An attempt is the made to develop an alignment with curves of similar radius to those measured. Once the proposed alignment is decided, the methods of control to stabiles the channel to its alignment are considered.
2. Cross section. The cross section is that built by the river itself, i.e., when the channel is uniform and does not show signs of accretion of retrogression. The proposed section is either by river contraction or by river diversion and is compared with the normal cross section with regard to gauge and discharge relation, velocity of flow, and total sediment runoff. The section is modified by successive analysis to bring it in line with the normal corss section as far as possible.