Floodplain
Explanation
Running water acts as a primary exogenic agent in shaping landforms. In the mature and old stages of a river's course, the slope creates conditions where deposition dominates over erosion. When a river overflows its banks, it deposits sediments on the surrounding land, creating specific depositional landforms.
Analysis of Options:
- Delta: Incorrect. A delta is a triangular depositional feature formed at the mouth of a river where it enters a standing body of water (such as a sea or lake), resulting in the stratification of sediments.
- Levee: Incorrect. Natural levees are raised banks or ridges found parallel to the river channel. They are formed by the deposition of coarser sediments immediately adjacent to the channel when the river overflows.
- Floodplain: Correct. A floodplain is a flat area of land next to a river, stretching from the banks of the river channel to the base of the enclosing valley walls. During floods, the river overflows its banks, and as the water spreads out, its velocity decreases. This leads to the deposition of fine soil and other sediments (alluvium), creating a flat and highly fertile landform.
- Meander: Incorrect. A meander is a loop-like bend or curve in the course of a river, formed by lateral erosion on the outer bank and deposition on the inner bank. It describes the path of the river, not the deposited land area.
Key Takeaway:
Floodplains are extensive flat areas of fertile soil formed by the deposition of fine sediments (silt) during river inundation, whereas Natural Levees are the raised ridges immediately bordering the river channel.