Question

how the delta is formed

Answer 1

When river reaches a lake or the sea the water slows down and loses the power to carry sediment. Some rivers drop so much sediment that waves and tides can’t carry it all away. It builds up in layers forming a delta

Answer 2

Answer:

As the river approaches the sea, the speed of the flowing water decreases and the river begins to break up into a number of streams called distributaries. The river becomes so slow that it begins to deposit its load. Each distributary forms its own mouth. The collection of sediments from all the mouths forms a delta.