Correct option is B
The rise of the water level on the upstream side of a structure, such as a weir or barrage, after its construction is termed as afflux. This occurs due to the obstruction created by the structure, which causes the water level to increase upstream.
Important Key Points:
1. Afflux Definition:
· Afflux is the increase in water level on the upstream side of a structure like a weir or barrage due to the reduction in flow area caused by the obstruction.
2. Significance:
· It is an important parameter in hydraulic design to ensure the safety of structures and nearby areas.
· It helps in determining the backwater effect and flood levels.
3. Formula for Afflux: Afflux can be calculated as:
