finals- streams Flashcards
(21 cards)
what is the shape of a stream longitudinal profile?
A longitudinal profile is like a side view/cross section of a stream and shows how it goes downstream. It is NOT like a ushape
What is the headwaters?
The beginning of a stream and the steepest part of the longitudinal profile
What is the depositional zone?
Where things start to deposit in a stream. The end. It starts to level out.
What is the transfer zone?
The middle of the stream, between the headwaters and the depositional zone.
What is bed load?
Bed load is the largest type of sediment that a stream can carry. It is not suspended/floating, but instead rolls along the bottom of the channel. This includes coarse sands and small pebbles.
What is suspended load?
Suspended load is a type of sediment that can float in the stream’s current. Oftentimes this includes fine sand, silt, and clay particles.
What is dissolved load?
Dissolved load is particles so small that they have dissolved into the stream’s water as a solution. An example of this would be calcium or sulfate.
What is a drainage basin?
A drainage basin is an area of land where all water makes its way to a single part, like a stream or body of water.
What are divides?
Divides are elevated terrains that separate drainage basins. Water goes to one side or the other, sort of like a roof.
What is turbulence?
A chaotic flow where currents twist around themselves
How does turbulence affect deposition and erosion?
Turbulence carries sediment more effectively???
What is laminar flow?
Not turbulence! When currents are simple and just go straight
How does flow rate affect deposition and erosion?
Faster water holds onto stuff for longer and erodes more?
What are stream meanders?
The curves in a stream
What is the cut bank? Point bar?
cut is on the outside- it’s where things get CUT from/eroded. point is where things are getting deposited. on the INSIDE
How do stream meanders evolve throughout time?
Their curves get more and more aggressive until it can get fully cut off into an oxbow lake, which looks like a horseshoe. Eventually, it closes up because it doesnt have any new water getting delivered to it. It becomes a swampy area and then its gone.
What are braided streams? How do they form?
Braided streams have multiple channels and have a high sediment load. Oftentimes they come off of glaciers because when glaciers melt they have a lot of sediment come with that.
What are levees? How do they form?
Levees are a raised bank of a stream that holds the stream in its banks. They are made from water naturally pushing sediment to the side. Sometimes humans build them on purpose too.
What happens to sediment at base level?
The base level is where water stops flowing and sediment deposits.
What is a flood exceedance probability diagram?
What is a stream terrace??
