The main process in the lower course is deposition. Water from other tributaries contributes to the main river therefore increasing discharge, but the river's energy is usually overpowered by the increased sediments. This section is also where the river meets with the lake, sea or ocean.
Braids are formed when a river splits into several distinct channels separated by islands called eyots or bars. When the load overpowers the river's energy to be carried any further, the river has few options but to drop some of the load. Braiding usually occurs when a river carry a lot of sediments
On fairly steep land
Alternating river discharge.
Erodible banks.
Sediments accumulate behind vegetation. Sometimes braids can be mixed up with meandering rivers
As the name suggest, these deltas resemble the foot of a bird. Bird's foot deltas extend and deposit their load further into the sea because the river's energy is more powerful than the sea tides and waves (rare). A good example is the Mississippi Birds Foot Delta in USA.
These form when ocean or sea waves hit head on with the river redistributing sediments evenly, Ebro in Spain is a good example.
Arcuate deltas are the most commonest types of deltas and mostly controlled by tides. They contain extensive distributaries that form a fan appearance. Niger Delta in Nigeria and Ganges in India and Bangladesh are good examples.
Delta's are advantageous as they provide very fertile lands for agriculture. The Ganges Delta is mostly used for farming purposes. However, land mismanagement often pose a threat to deltas. Infrastructure such as dams and HEP and tempering with river flows often prevents the formation of deltas. Dams collects sediments behind them and reduce sediment supply for delta formation.
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