What are river potholes?

What are river potholes?

In Earth science, a pothole is a smooth, bowl-shaped or cylindrical hollow, generally deeper than wide, found carved into the rocky bed of a watercourse. Other names used for riverine potholes are pot, (stream) kettle, giant’s kettle, evorsion, hollow, rock mill, churn hole, eddy mill, and kolk.

Which of the following is an example of potholes in river beds?

Solution(By Examveda Team) Formation of potholes in river beds is an example of corrosion. Corrosion is the deterioration of a metal as a result of chemical reactions between it and the surrounding environment.

Why do potholes form on the bottom of a stream?

Formed by water action A river pothole is a cylindrical, bowl-shaped, or irregular hollow that is usually deeper than wide. It is formed in the rocky bed of a stream by either the grinding action of sediment whirled around by stream eddies or the force of fast flowing water.

What is in the upper course of a river?

Upper course river features include steep-sided V-shaped valleys, interlocking spurs, rapids, waterfalls and gorges. Middle course river features include wider, shallower valleys, meanders, and oxbow lakes. Lower course river features include wide flat-bottomed valleys, floodplains and deltas.

What do you mean by potholes?

1a : a circular hole formed in the rocky bed of a river by the grinding action of stones or gravel whirled round by the water. b : a sizable rounded often water-filled depression in land. 2 : a pot-shaped hole in a road surface.

How do humans use the upper course of a river?

Upper course Here are the main land uses along with some of the reasons for their suitability. Tourism – sightseeing, gorge walking. Waterfalls and ravines can be spectacular. Angling – good source of income for landowners, especially in salmon rivers.

What kind of sediments are deposited in a stream bed?

At 100 cm/s, for example, silt, sand, and medium gravel will be eroded from the stream bed and transported in suspension, coarse gravel will be held in suspension, pebbles will be both transported and deposited, and cobbles and boulders will remain stationary on the stream bed.

What happens to streams during the mature stage?

Following tectonic uplift, streams erode quickly, developing deep V-shaped valleys that tend to follow relatively straight paths. Gradients are high, and profiles are ungraded. Rapids and waterfalls are common. During the mature stage, streams erode wider valleys and start to deposit thick sediment layers.

Why do particles stay on the bottom of a stream?

Smaller particles may rest on the bottom some of the time, where they can be moved by saltation and traction, but they can also be held in suspension in the flowing water, especially at higher velocities.

When does a stream reach its greatest velocity?

A stream typically reaches its greatest velocity when it is close to flooding over its banks. This is known as the bank-full stage, as shown in Figure 13.17. As soon as the flooding stream overtops its banks and occupies the wide area of its flood plain, the water has a much larger area to flow through and the velocity drops significantly.