The raised banks along a river in a floodplain are known as:

Correct Option

The correct option is

Levees

Explanation

Levees are significant depositional landforms associated with the mature and old stages of a river's course. They are natural embankments formed parallel to the river channel through the accumulation of sediments during periodic flooding.

Option Analysis

• Deltas: Incorrect. Deltas are depositional features formed at the mouth of a river where it enters a standing body of water (like a sea or lake), resulting in the triangular deposition of sediments. They are not raised banks along the river's course.
• Levees: Correct. Natural levees are low, linear, and parallel ridges of coarse deposits found along the banks of rivers. During flooding, water spills over the river banks, and the velocity decreases rapidly. This causes the coarser load to be deposited immediately adjacent to the channel, building up raised banks known as levees.
• Moraines: Incorrect. Moraines are accumulations of dirt and rocks (glacial till) that have fallen onto the glacier surface or have been pushed along by the glacier as it moves. They are glacial landforms, not fluvial (river) landforms.
• Dunes: Incorrect. Dunes are mounds or ridges of sand formed by the wind (aeolian processes), typically found in deserts or along coastlines. They are not associated with river floodplains.

Key Takeaway

Natural Levees are raised embankments formed along river banks due to the deposition of coarse sediments during floods, serving to contain the river within its channel during normal flow.