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Meander

A looplike bend in the course of a river

Fast moving:

A lot of sediments of various sizes

What is meant by watershed (drainage basin)?

all of the land where rainfall drains into the main river or one of it's tributaries

Exfoliation

as underlying rock layers are exposed, there is less pressure on them and they expand which causes the rigid layers to crack and sections to slide off

how it is transported: boulders

bedload

how it is transported: pebbles

bedload

how it is transported: sand

bedload

shape of valley old age

broad u shaped

Frost wedging

cracking of rock mass by the expansion of water as it freezes in crevices and cracks

nature of meanders maturity

curves

youth type of erosion

downcutting

Amount of uplands in old age

flat

amount of discharge maturity

greater than youthful river

Amount of uplands in maturity

hills

how it is transported: calcium

in solution

How do streams transport sediments?

in solution, in suspension, bedload

maturity type of erosion

lateral

old age type of erosion

lateral

size of sediments maturity

medium-small sediments

maturity slope or gradient

moderate

Amount of uplands in youth

mountains

abraision

moving sediments or rock sections can break off pieces from a rock surface they strike

amount of discharge old age

quite large

bedload

sediment are bouncing along the bottom of the river

old age slope or gradient

shallow

size of sediments old age

small sized

size of sediments youth

smalle - large

how it is transported: magnesium

solution

youth slope or gradient

steep

nature of meanders youth

straight

how it is transported: clay

suspension

how it is transported: fine sand

suspension

how it is transported: silt

suspension

Steam channel

the course the water in a stream follows.

nature of meanders old age

the most curves

Erosion

the transportation of weathered material from location a to location b

Discharge

the volume of water flowing past certain point in a given unit of time

amount of discharge youth

very low

Mechanical Weathering

when physical forces break rock into smaller and smaller pieces without changing the rock's mineral composition Physical weathering

Chemical weathering

when rocks and minerals undergo changes in their composition because chemical bonds between atoms are broken, rearranged etc

headwaters of a river?

where a river starts

mouth of the river

where the reverends

Gradient

A slope

What is the relationship between a stream and a drainage basin?

A stream discharges into a drainage basin. A drainage basin is a tract of land drained by a river and its tributaries.

Talus

An accumulation of rock debris at the base of a cliff.

What factor most influences the power of a stream to erode and transport material?

Gradient

What is velocity?

How fast a river is moving

How does chemical weathering affect the compounds in a rock?

It changes them

What happens to a rock's mineral composition during mechanical weathering?

It stays the same

What is unloading? How does it contribute to weathering?

Large masses of igneous rock may be exposed through uplift and erosion of overlying rocks. When that happens, the pressure exerted on the igneous rock is reduced. This increases the surface area of the rock. The increase in surface area allows for an increase in chemical weathering.

Slow moving:

Less sediments that tend to be smaller

How might lowering base level affect stream erosion?

Lowering base level increases the vertical distance between the source and destination increasing energy.

Base level

Lowest elevation to which the stream can erode downward, for many streams, the water surface level of the body of water into which they flow

More discharge means

More sediments that can be carried

deposition

Process in which sediment is laid down in new locations.

Name two rock characteristics and two climatic factors that affect the rate of weathering

Rock chemistry, and size. Temperature and wind.

In solution

Sediments are dissolved

In suspension

Sediments are floating the entire time

What affects the speed of weathering?

Surface exposure: the more of a rock that is shown to the environment, the quicker the rock is weathered composition: Sedimentary rocks usually weather quicker than igneous and metamorphic climate: amount of water present and temperature differences

How do gradient and discharge change between a steam's headwaters and its mouth?

The gradient gets less steep. The discharge get bigger.

What is a divide?

The high land that seperates one watershed from another

shape of valley maturity

U shaped

shape of valley youth

V shaped

What are the factors that determine the amount and size of sediments?

Velocity, gradient, discharge

HIgh gradient

Water moves faster, and there are more sediments

Low gradient

Water moves slower, and there are less sediments

Tributary

a stream that runs into a bigger stream or river

How do streams erode their channels?

abrasion, grinding, and by dissolving soluble material.