What does erosion mean in river terminology?

In river terminology, erosion refers to the process by which soil and rock are removed from the surface and transported by the river. This involves the wearing away of the earth's surface due to the action of flowing water, which not only breaks down the materials but also carries them downstream. Erosion is a key component of the river's cycle, playing a critical role in shaping landscapes and forming features like valleys and gorges.

The process of erosion contributes to the dynamic nature of river systems, impacting both the environment and ecosystems along riverbanks. As the river flows, it picks up sediments and materials from the bed and banks, leading to continual changes in its course and sediment load. This movement of materials is essential for nutrient distribution and can affect water quality, habitat diversity, and the overall geomorphology of the area.

Other options focus on different aspects of river processes, such as deposition, which is the accumulation of materials rather than their removal, and the creation of new channels, which involves alterations to the river's pathway rather than the process of erosion itself. Understanding erosion is crucial for grasping how rivers function and change over time.