oxbow lake

Thân thiện

A river's meander has been cut off, forming a distinct oxbow lake.

Definition

Noun: A U-shaped or crescent-shaped body of water that was formerly a meander (a bend) in a river. It forms when a river changes its course, cutting off the meander and leaving the isolated, curved water body behind. These lakes are often temporary and may eventually fill with sediment and vegetation.

Usage

This term is used specifically in physical geography and geology to describe a distinct landform feature created by fluvial (river) processes. * It is a countable noun (e.g., an oxbow lake, several oxbow lakes). * It is typically modified by adjectives related to location, size, or state (e.g., a large oxbow lake, the ancient oxbow lake, a silted-up oxbow lake).

Examples

• From the air, you can clearly see the oxbow lake that marks the river's old path.
• The floodplain is dotted with oxbow lakes, evidence of the river's shifting course over centuries.
• Ecologists studied the plant life in the stagnant waters of the oxbow lake.

Advanced Usage

• Formation Process: The term is intrinsically linked to the geomorphological process of meander cutoff. An oxbow lake is the result of this process.
• Ecological Context: Oxbow lakes are often discussed as important wetland habitats, serving as nurseries for fish or habitats for birds, distinct from the flowing river channel.

Variants and Related Words

• Oxbow (noun): Can refer to the U-shaped bend itself or, by extension, the lake formed from it. In this specific geographical sense, "oxbow" is often synonymous with "oxbow lake."
• Meander (noun): A winding curve or bend in a river, which is the precursor to an oxbow lake.
• Cutoff (noun): The event where the river breaks through the narrow neck of a meander, abandoning its old loop.

Synonyms

• Billabong (Australian English): A stagnant pool or lagoon that was originally part of a river channel; often synonymous with oxbow lake in Australian usage.
• Mortlake (archaic/rare): An old term for a lake formed from a river's abandoned channel.

Related Phrases/Concepts

• Fluvial landform: Oxbow lakes are a type of fluvial landform.
• Abandoned channel: This is a descriptive phrase for what an oxbow lake represents.
• Point bar: A depositional feature on the inside of a river bend, often found opposite the eventual cutoff point that creates an oxbow lake.

Học thuật

Noun

1. a crescent-shaped lake (often temporary) that is formed when a meander of a river is cut off from the main channel