Chapter 6 - Streams & Flooding Flashcards
What is the hydrosphere?
All the water at and near the surface of the earth.
What is a stream?
Any body of flowing water confined within a channel, regardless of size.
What is a drainage basin?
The region from which a stream draws water.
What is a divide?
It is what separates drainage basins.
What is discharge?
The volume of water flowing past a given point.
What is a traction load?
Heavy debris that is being rolled, dragged or pushed along the bottom of a stream bed.
What is saltation?
Material of intermediate size carried in short hops along a stream bed.
What is the suspended load?
It is material that is light enough to be moved along suspended in the stream.
What is a dissolved load?
Substances that are completely dissolved in the water of a stream.
What is the load?
The total quantity of material that a stream transports.
What is a stream capacity?
It is a measure of the total load of material a stream can move. (Closely related to discharge)
What is the gradient?
The steepness of a stream channel.
What is the base level?
The lowest elevation to which the stream can erode downward.
What is the longitudinal profile?
It is a sketch of the stream’s elevation from source to mouth.
What is a delta?
It is a large, fan-shaped pile of sediment.
What is an alluvial fan?
A similarly shaped feature to a delta, but is formed when a tributary stream flows into a more slowly flowing, larger stream.
What is a meander?
It is a kink in a stream formed by erosion.
What is a cut bank?
It is where a stream tends to flow faster.
What are point bars?
Sediment that is deposited on the inside of meanders.
What is a flood plain?
It is the area into which a stream spills over during floods.
What is known as infiltration?
When water from precipitation sinks into the ground.
What is known as percolation?
When water moves through soil and rock.
What is termed the stage of a stream?
The elevation of the water surface at any point.
When does a stream crest?
When it’s maximum stage has been reached.
What are upstream floods?
Floods that only affect small, localized areas.
What are downstream floods?
Floods that affect large stream systems and large drainage basins.
What are flash floods?
They are a variety of upstream flood characterized by a rapid rise of stream stage.
What are ephemeral streams?
They are streams that only flood occasionally.
What does the recurrence interval describe?
How frequently a flood of of a certain severity occurs (on average) for a certain stream.
What are retention ponds?
They are large basins that trap some of the surface runoff, keeping it from flowing immediately into a stream.
What does channelization mean?
Various modifications of the stream channel itself that are usually intended to increase the velocity of water flow
What are levees?
Raised banks along a stream channel.
