[amp_mcq option1=”groynes” option2=”construction of dykes or leavees” option3=”both (A) and (B)” option4=”groynes and bandalling” correct=”option3″]
The correct answer is C. Both (A) and (B).
Groynes are structures built perpendicular to the shoreline to trap sediment and prevent it from being washed away by the current. They are typically made of wood, stone, or concrete, and can be either permanent or temporary.
Dykes or levees are embankments built along the banks of a river to prevent flooding. They are typically made of earth or stone, and can be either natural or artificial.
Both groynes and dykes or levees can be used to train a river for depth. Groynes help to keep the river channel clear of sediment, while dykes or levees help to prevent the river from overflowing its banks. This can help to maintain a consistent depth of water in the river, which is important for navigation and other activities.
Bandalling is a technique that is sometimes used to train a river for depth. It involves placing large rocks or boulders in the riverbed to create a barrier that prevents the river from eroding the banks. Bandalling can be effective in preventing flooding, but it can also have a negative impact on the river’s ecosystem.
In conclusion, the correct answer to the question “River training for depth is achieved by” is C. Both (A) and (B). Groynes and dykes or levees are both effective methods of training a river for depth.