Delta
Explanation
River deposition occurs when the velocity of a river decreases as it enters a standing body of water, such as a sea or a lake. This loss of kinetic energy forces the river to drop its sediment load. As the main channel becomes obstructed by deposits, it bifurcates into smaller channels known as distributaries.
Option Analysis
- Levee (Incorrect): Natural levees are linear, parallel ridges of coarse deposits found along the banks of a river. They are formed during flooding when the river overflows its banks, rather than at the mouth of the river where it meets the sea.
- Delta (Correct): A delta is a depositional feature formed at the mouth of a river. The collection of sediments deposited by the network of distributaries accumulates to form this landform, which often resembles the Greek letter delta (Δ).
- Beach (Incorrect): A beach is a coastal landform consisting of loose particles like sand, gravel, or pebbles. It is primarily formed by the depositional action of sea waves and currents, not by river distributaries.
- Cliff (Incorrect): A cliff is a steep rock face along a coast. It is an erosional landform created by the abrasive action of marine waves, distinct from depositional features like deltas.
Key Takeaway: A delta is the triangular depositional landform created at a river's mouth due to the accumulation of sediments discharged by its distributaries as the river's velocity dissipates.