In fluvial geomorphology, what is the broad, low embankment built up along the banks of a river channel during floods commonly called?

Introduction / Context:
This question is about basic physical geography, specifically landforms created by rivers. During floods, rivers can deposit sediments along their banks, creating natural embankments. Understanding the correct terminology for these features helps students accurately describe river processes and interpret diagrams in geography textbooks. The term commonly used for such a broad, low embankment is an important concept for examinations that include geomorphology and environmental studies.

Given Data / Assumptions:

• The landform is a broad, low embankment.
• It is formed along the banks of a river channel.
• It develops during flood events when the river overflows.
• Options are delta, levee, flood plain and dune.

Concept / Approach:
When a river overflows during floods, water spills over the banks and loses velocity. As velocity drops, the heavier sediments are deposited close to the channel edges, gradually building up ridges. These natural embankments along the river are called levees. Deltas form at river mouths where they enter a standing body of water. Flood plains refer to the wider low lying area that may be inundated during floods. Dunes are wind formed sand features, usually in deserts or coastal regions. Therefore, the correct term for the embankment along the river banks is levee.

Step-by-Step Solution:
Step 1: Focus on the key description: a broad, low embankment along the river banks built up during floods. Step 2: Recall from river geomorphology that natural ridges formed by sediment deposition on river banks are called levees. Step 3: Compare this description with the meaning of delta, which forms at the river mouth where it meets seas or lakes, not along the banks. Step 4: Recognise that flood plain refers to a larger flat area adjacent to the river, not the embankment itself. Step 5: Note that dunes are wind shaped sandy hills, not river created embankments. Step 6: Conclude that the only option matching the described landform is levee.

Verification / Alternative check:
An alternative check is to remember that many flood control structures built by humans to mimic or reinforce natural embankments are also called levees. News reports often mention levees breaking during major floods. This word association reinforces that levee is the term for an embankment adjacent to the river channel. Visual diagrams in school geography books typically label the natural ridge next to the river as a levee, while marking a much wider area as the flood plain. Keeping this picture in mind confirms that levee is the correct term here.

Why Other Options Are Wrong:
Delta: A delta is a depositional landform at the mouth of a river where it meets an ocean, sea or lake, not an embankment along the banks.
Flood plain: A flood plain is the entire low lying area around a river that may be submerged during floods, not just the raised embankment beside the channel.
Dune: A dune is a wind formed hill or ridge of sand found mainly in deserts and coastal areas and is not associated with river bank sediment deposition.

Common Pitfalls:
Students sometimes confuse levees, flood plains and deltas because all involve deposition. A typical mistake is to choose flood plain because it is closely connected with floods. Another error is to select delta due to its popularity in exam questions. To avoid confusion, remember that levee is narrow and raised next to the river, flood plain is broader and flat, and delta is at the mouth of the river. Visualising cross sections of a river valley can help keep these terms distinct during exams.

Final Answer:
The broad, low embankment built up along the banks of a river channel during floods is called a levee.