Which of the following factors leads/lead to the formation of meanders? 1. High gradient of river channel 2. Coriolis force 3. Irregularities on the river banks Select the correct answer using the code given below:

Meander is not a landform, but is only a type of channel pattern. This is because of:

(i) propensity of water flowing over very gentle gradients to work laterally on the banks;

(ii) unconsolidated nature of alluvial deposits making up the banks with many irregularities, which can be used by water exerting pressure laterally;

(iii) coriolis force acting on the fluid water deflecting it like it deflects the wind. When the gradient of the channel becomes extremely low, water flows leisurely and starts working laterally.

Slight irregularities along the banks slowly get transformed into a small curvature in the banks. The curvature deepens due to deposition on the inside of the curve and erosion along the bank on the outside.

If there is no deposition and no erosion or undercutting, the tendency to meander is reduced. Normally, in meanders of large rivers, there is active deposition along the concave bank and undercutting along the convex bank.

The concave bank is known as the cut-off bank, which shows up as a steep scarp and the convex bank presents a long, gentle profile.

As meanders grow into deep loops, the same may get cut-off due to erosion at the inflection points and are left as ox-bow lakes.