Floodplains
Explanation
Fluvial (river) landforms are categorized into erosional and depositional forms based on the dominant geomorphic process. Deposition occurs primarily in the middle and lower courses of a river when the water velocity decreases, reducing the river's capacity to transport its sediment load.- Waterfalls is Incorrect: Waterfalls are erosional landforms typically found in the upper course (youth stage) of a river. They result from vertical erosion and the downcutting of the riverbed, particularly where resistant rock bands exist.
- Meanders (initially) is Incorrect: Meanders are loop-like channel patterns formed by a combination of lateral erosion (on the concave bank) and deposition (on the convex bank). While deposition is involved, meanders are primarily channel features, whereas floodplains are extensive landforms resulting specifically from sediment accumulation.
- Floodplains is Correct: Floodplains are characteristic depositional landforms. They are formed when a river overflows its banks, causing the velocity of the water to drop and leading to the deposition of fine sediments (alluvium) over the adjacent land.
- Gorges is Incorrect: Gorges are deep valleys with very steep to straight sides formed by intense vertical erosion (downcutting) in the upper course of a river.
Key Takeaway: The primary depositional landforms of a river include floodplains, natural levees, and deltas. In contrast, gorges, canyons, and waterfalls are primary erosional features.