Deltas:
They are formed by the process deposition and is a land form that is created at the mouth of a river where the river flows into the ocean, sea, lake, flat arid area or another river. The river has to flow along alternative channels called distributaries when sediments build up and block the flow of the river to the sea. A delta will only form when the river carries a large amount of sediment and the waves along the coast are not too strong until they remove the sediments faster than the river can deposit them.

-Kimberly-