Answer:
A river delta is a landform that is formed at the mouth of a river from the deposition of sediment carried by the river as the water flows.
Step-by-step explanation:
A land type generated by sediment deposition which is loaded by a river as the flow leaves its mouth and joins slower-moving or stagnating water, this is called as "a river delta". Its occurrence is possible in an entrance of ocean, reservoir, sea, lake, estuary etc.
The size and shape of a delta is controlled by balancing sediment-supplying watershed processes and receiving basin processes that sequester, redistribute and export that sediment. It also plays an important role in delta evolution. And have huge importance in human civilization, being the agricultural production centers and population centers.