Model Question and Answers for APSC | There is no formation of deltas by rivers of the Western Ghat. Why?

Ans: Deltas are wetlands that form as rivers empty their water and sediment into another body of water, such as an ocean, lake, or another river. Although very uncommon, deltas can also empty into the land. A river moves more slowly as it nears its mouth or end. This causes sediment, solid material carried downstream by currents, to fall to the river bottom.

The slowing velocity of the river and the build-up of sediment allows the river to break from its single channel as it nears its mouth. Under the right conditions, a river forms a deltaic lobe. A mature deltaic lobe includes a distributary network—a series of smaller, shallower channels, called distributaries, that branch off from the mainstream of the river.

Not all rivers form deltas. For a delta to form, the flow of a river must be slow and steady enough for silt to be deposited and built up.

No formation of deltas by rivers of the Western Ghat:

1. The slope of the Western Ghats is steep and that is the reason that these rivers have a rapid flow. They don’t have to travel much distance to drain into the sea. As a result, they don’t carry a lots of sediments required to form deltas.
2. At the same time, the Narmada and Tapti rivers flow in the rift valleys. So the eroded material carried by them gets deposited in the fractures of the fault zones.
3. The western coast is submerging one having higher depth where it would be difficult for sediments to accumulate
4. A river will also not form a delta if exposed to powerful waves.
5. Tides also limit where deltas can form. The Amazon, the largest river in the world, is without a delta. The tides of the Atlantic Ocean are too strong to allow silt to create a delta on the Amazon.