What causes point bars and cut banks to form? What will be an ...

[xroflmao]

What causes point bars and cut banks to form? What will be an ideal response?

Question 2

How do oxbow lakes form? What will be an ideal response?

[rleezy04]

Answer to Question 1

There is a general tendency for rivers and streams to form curved rather than straight channels. Once
channels become curved, the water current moving through them shifts from one side of the river to
the other in a regular and predictable way. For example, a passenger riding in a car following a curving
road will be alternately swayed from one side of the car toward the other and back again by inertia.
Similarly, water in a curving river channel will be shifted from one side of the channel to the other by
inertia, as the river changes direction. The net result of this is that the outboard sides of river bends
receive the lion's share of the energy as the river water gets shifted to that side. A consequence of this
is accelerated erosion in the form of a cut bank. On the inboard side, current energy is predictably
decreased. A consequence of this is deposition of sediment in the form of point bars

Answer to Question 2

Low-gradient river systems are commonly dominated by meandering channel patterns characterized by
tight looping bends shaped like curves in a winding mountain road. These channels migrate through
time. In some instances, the curvature of the channels becomes so pronounced that two channels will
actually intersect each other and form what is called a cut off. The term cutoff is applied because one
bend of the river gets essentially amputated and isolated from the rest of the river. As water continues
to flow through the cutoff, the water left in the abandoned channel becomes a stagnant lake. This lake
is called an oxbow lake.