Exam 10: Streams and Floods

Point bars are sandbars deposited in the middle of river channels.

A(n) ___ is a step-like landform found above a stream and its floodplain. It is a remnant of an older flood plain or river-eroded flat surface.

Stream-dominated river deltas, like the Mississippi, display the characteristic triangular shape of a delta.

A stream can lengthen its valley by headward erosion.

A bar in a river channel is a ridge of sediment, usually sand and gravel, deposited in the middle or along the banks of a stream.

The movement and interchange of water between the sea, air and land can be visualized by the ____.

The gravel bed load of a stream moves by _____.

A(n) ___ stream flows in a network of rivulets (subchannels) around numerous sandbars.

Saltation of sand grains begins when they are dissolved.

The ______ load is sediment light enough to remain lifted indefinitely above the bottom by water turbulence.

___ influences the velocity of a river along with gradient.

The process of deepening a valley by erosion of the streambed is called downcutting.

The limit to downcutting of a stream is called the ___ level.

Drainage basins are bowl-shaped depressions with a lake in the middle, and all streams in the basin discharge their water and sediment into that lake.

Rivers may develop pronounced sinuous (wiggly) curves called a ___ pattern.

Stream erosion and deposition are controlled primarily by a river's velocity.

The ______ is the total area drained by a river and its tributaries.

The discharge of a stream is the volume of water that passes a given point in unit of time (for example, 50 cubic meters per second).

The interrelationship of the hydrosphere, geosphere, biosphere, and atmosphere is visualized through the hydrogeologic cycle.

A(n) ___ drainage pattern of a river resembles a tree.