Curves in Channels
Usually, it is tried to align a canal along a straight line but in many cases curves can't be avoided and it becomes necessary to provide curves in a channel. Whenever a curve is provided in an unlined canal, it is assured that the provided curve is as gentle as possible. Curves cause disturbance in the flow causing scoring on the outside (Concave side of the curve) and silting on the inside (Convex side of the curve).
Pitching is therefore recommended on the concave side of the curve to avoid scouring. The radius of the curve depends on the rate of discharge in a channel, the higher the discharge higher will be the radius of the curve. The recommended radius of the curve for different discharge values is tabulated below.
Discharge Capacity of Channels (in cumecs) |
Minimum recommended Curve Radius (in meters) |
| Over 100 | 1500 |
| 30-100 | 900 |
| 15-30 | 600 |
| 3-15 | 300 |
| 0.5-3 | 150 |
| Less than 0.5 | 100 |
