geo 4 fluvial

fluvial processes and landforma

what does fluvial mean

the process of rivers and streams and landforms created by them

what does long profile of a river display

it shows how the river loses height with increasing distance towards the sea

what are the typical characteristics of upper coast rivers

the upper course is typified by v shaped valleys.

what created v shaped valleys

vertical erosion

what is the process of making upper course river

mostly vertical erosion, hydraulic and attrition

what are the typical characteristics of the middle course

valley getting wider,

why does the middle course get wider

increase in lateral erosion

what does the lower course of a river tend to carry

large amount of sediment

what is watershed

an area or ridge of land that separates waters flowing to different rivers, __basins__, or __seas__.

what are tributaries

smaller rivers that connect to the large rivers

what is a river basin

A river basin is the portion of land drained by a river and its tributaries

what are 3 different patterns of river systems

dendtiritc, trellis, and radial

what does dendritic pattern look like

looks like tree branches

where is dendritic drainage most common

the carribean region

how does trellis look like

appearance for a rectangular grid

what are the main processes of fluvial erosion

abrasion, attrition, corrosion, hydraulic action

what is abrasion

the erosion of the river bottom and the river bank by material being carried out by the river itself

what is attrition

the rocks and pebbles being carried by the river, crash against each other, wearing them down to become smaller rounded pebbled

what is corrosion

the chemical erosion of rocks on the river banks by the slightly acidic water. this occurs in streams running through rocks such as limestone

what is hydraulic action

the water forces air to be trapped and pressured into cracks in the rocks on the banks of the river. this constant pressure eventually causes the rocks to crack and break apart

what happens to the material in the river after its eroded

the material in the river is transported down the river.

what are the 4 main processes of fluvial transportation that transport the eroded material

traction, saltation, suspension, solution

what is traction

the largest rocks in the river are slowly rolled along the bottom of the river by the force of water.

what is saltation

smaller rocks are bounced along the river bed,

what is suspension

the water carries smaller particles of the matter.

what is solution

material dissolved within the water and carried along by it.

when does fluvial deposition occur

when the river loses energy and can not continue to carry the material it is transporting

what are the main erosional landforms

potholes, gorges, waterfalls, rapids,

what are potholes

cylindrical holes drilled into the bedholes of a river that varyin depth and diameter.

how are potholes formed

the fast flowing water with heavy load erodes and weakens the rock and create a depression in the rock

what do pebbles do to potholes

the pebbled drill into the depressions making them more circular, wider and deep.

what makes potholes deeper

pebblesq

what are valleys the result of

erosion by river and weathering

what is a gorge

a narrow valley between 2 rocky walls that are usually mountain or hills

what flows down a gorge

river or some stream of water

what makes gorges, valleys and canyons different

they way they were created

difference between gorge and canyons

gorges are usually more narrow and steeper then canyons. canyons do not always have a stream of water moving across the bottom of the ravine as gorges usually do

how is a gorge formed

gorges are the result of erosion and geological uplift after long periods of time

what wears down a rock and what will happen to it

when streams and rivers flow down mountains they break away and wear down the rock until it becomes steep and narrow.

what is defined as the vertical uplift of the earths surface

geological uplift

when do waterfalls develop

when a change in rock type takes place along the river source resulting in erosion

what is a rapid

rapids are sections in a river where the gradient of the river bed is relatively steep resulting in an increase in the river turbulence and velocity

where do rapids form

where the gradient of the river is steep and the bed is composed of mainly hardrocks

what is deposition

the process where material being transported by a river is deposited

where does deposition occur

when a river loses energy

what is a meander

a bend in the river channel

where do meander form

when water in the river erodes the outside of a channel

what are rifles and pools

rifle is the shallow section and the pool is the deep section

what causes river channels to bend

the flow in the river is uneven due to the rifles and pools so the maximum flow is concentrated on one side of the river. this increases erosion on one side of the river and deposition on the other, causing the rivers channel to bend

what is an oxbow lake

it is a lake or pool that forms when a meander river is cut of

what is oxbow lake an evolution of

meander

where does erosion and deposition take place in an oxbow lake

strong erosion takes place on the outside bend and deposition takes place on the inside bend

what is a braided channel

braided channels consist of small network of river channels separated by small islands called eyots

what is a flood plane

large expanses of land that form on either side of the river

what is a leeve

A levee is a natural wall that blocks water from going where we don't want it to go.

what is a leeve made out of

earth

what are deltas

wetlands that form as a river, empty their water and sediment into another body of water like ocean lake or another river

what does precipitation fall in

the drainage basin

what is the drainage basin a part of

the hydrological cycle

what is the first process that happens in the river

erosion

what is erosion

the wearing away of land

what is water cycle

water constantly circulating between earths surface and the atmosphere above

what is the importance of a river

it is full of living creatures. rivers supply water to many towns and cities. rivers help travel across the earth especially before modern roads were constructed.

how do waves form coastal landforms

by the constant action of waves, tides, and currents.

what is a swash

water is washed up on the beach

what is backwash

when water runs down the beach

when is swash stronger

constructive wave

when is backwash stronger

destructive wave

why does a wave slow down when it aproaches the beach

friction between the water and the beach

what causes waves to break

friction between the water and the beach

relation between the wing and the strength of the wave

stronger the wing stronger the wave

what are the 2 types of waves

constructive and destructive waves

constructive waves

help build beaches. each wave is low.

when are constructive waves common

the summer

when are destructive waves common

the winter

destructive waves

destroy beaches, waves are high and frequent.

how are shorelines made

waves, tides, and currents help create shorelines. when eaves crash on the shore they wear away the eland

how long do coastal changes take

100 years

what does the way coasts are formed depend on

what material is in the land or water, the harder the land the harder to erode

types of erosional landforms

sea clif, wave cut platforms, sea caves, sea arches, sea stack, stump, headlands

why are sea cliffs steep

because of the wave induced erosion near sea level

how are wave cut platforms fored

when the sea waves strike against a cliff, the cliff gets eroded and gradually retreats. with constant pounding by the waves, as the cliff recedes, an eroded bases is left behind to create a flat surface.

how are sea cave formed

prolonged attack of waves against the base of the cliff that gets smashed against the cliff creates holes in the regions of weakness. these holes get further widened and deepened to form sea caves.

how are stumps formed

stacks gradually erode and all that is left is a stump.

how are sea arches formed

when 2 caves approach each other from either side and unite to form a bridge like structure known as a arch

how are sea stacks formed

continous erosion under the attack of a wave can result in the total collapse of an arch. it is an isolated pillar of rock that is not permanent and will disapear

where are headlands formed

hards ricks that are resistant to erosion

what is a headland

an area of resistant rock that extends from the coastline to the city. it stick out into the sea and i surrounded by water on 3 side

soft engineering flood prevention

reforestation, flood plain zoning, mitigation

hard engineering flood prevention

dams, flood releif channels, embankments

what are the 3 processes in a river

1. erosion
2. transportation
3. deposition

what is reforestation

replanting forests or planting new forests protect the ecosystem.

what is the disadvantage of reforestation

it is difficult to plant forests in urban areas.

advantages of flood warning

people are prepared like having insurance

disadvantages of flood warning

not all people have access to methods of warning and it does not stop the flood

advantages of a dam

the amount of water flowing downstream is controlled. it provides hydroelectric powder.

disadvantage of a dam

it is very expensive

advantages of flood relief channels

it reduces the risk of flooding

disadvantages of flood relief channels

it is expensive and hard to build in urban areas

what is a flood relief channel

some of the water is directed away from the river and released back further upstream or into the river or lake.