Meandering, characterized by the sinuous curves found in rivers, predominantly occurs in the middle and lower sections.

The formation of meanders involves a series of processes:

• As the river’s gradient becomes gradually gentler, the water flows leisurely and starts moving laterally.
• This lateral pressure erodes the unconsolidated alluvial deposits that form the banks.
• Additionally, the coriolis force acting on the fluid water causes deflection and changes in direction, intensifying erosion and deposition along the banks.
• Small irregularities along the banks gradually transform into bends, which deepen due to deposition on the inner curve (convex bank) and erosion along the outer bank (concave bank).
• When there is no significant deposition, erosion, or undercutting, the inclination towards meandering diminishes.

In some cases, meanders can cut deep and wide through hard rock formations, forming entrenched or incised meanders. However, these meanders typically develop during land upliftment when the river is in its youth. Over time, they widen and deepen, eventually transforming into deep gorges or canyons.

The movement of a river laterally and the deposition that occurs during periodic flooding contribute to the formation of floodplains. Erosion on one bank is counterbalanced by deposition on the opposite side, resulting in the development of distinct landforms, including:

• Natural levees: These low, linear ridges of coarse deposits are commonly found along the banks of large rivers. They often take the form of individual mounds and play a crucial role in preventing the overflow of water onto the floodplain.
• Point bars: Also referred to as meander bars, point bars consist of sediments deposited linearly along the concave side of meanders in large rivers. They possess a uniform profile and width, containing a mixture of sediment sizes.
• Cut-off/slip-off banks: In meanders of large rivers, active deposition occurs along the concave bank, while undercutting takes place along the convex bank. The concave bank is known as a cut-off bank, featuring a steep scarp, while the convex bank presents a long, gentle profile.
• Ox-bow lakes: Over time, as meanders gradually elongate into deep loops, erosion at the inflection points can cause the formation of cut-offs, resulting in the creation of ox-bow lakes.

Conclusion: Thus, the dynamic flow of rivers gives rise to a myriad of landforms on floodplains or delta plains, contributing to the ever-changing landscape.

Legacy Editor Changed status to publish January 5, 2024