Water On The Land Flashcards
What is headwaters
The beginning or source of a river
What is a river flow
The amount of water in the channel
What is a river channel
The path a river takes is called a channel it’s shape and size depends on the amount of water that has been flowing in it, how long it’s been flowing and the type of rocks and soil over which it flows
What is a floodplain
A flag low lying area along the river that gets covered with water when the river overflows
What is a river bank
The land immediately along the river
What is wetlands
A low lying area where wafer covers the soil for much of the year
What is a river mouth/ delta
The end of the river where it meets a lake or ocean
What is a river
A moving body of water which flows downhill from the place it begins, the source, to the point it enters the sea or lake,the mouth.
What is the point called when a tributary joins the main river
Confluence
What is the area of land which is drained by the river and its tributaries called
Drainage basin
What is the boundary of the drainage basin called and its characteristic
The watershed and is usually a ridge of high land
Why does the landscape change as it gets further down the river
A result of the processes of erosion, transportation and deposition. The extent it can change is a result of how much energy the river has and how resistant the land is
What is the hydrological cycle
The cycling of water through the sea land and atmosphere
What is precipitation
Water in any form which falls to the earth it includes rain sleet snow and hail
What is interception
Where vegetation catches precipitation
What is surface runoff
Water flowing over the land towards the channel as a result of very heavy rain or the soil being saturated
What is infiltration
The downward movement of water from the surface into the soil pores
What is throughflow
The movement of water sideways through the soil towards the river
What is groundwater
Water stored mainly within the pores of underlying rocks such as sandstone
What is groundwater flow
Water moves slowly through the bedrock towards the river. This flow can keep rivers flowing for many months without rain
What is a water table
The level below which the ground is saturated
What is evaporation
The process by which liquid water changes to water vapour when warmed
What is transpiration
The process by which plants give off water vapour via the pores in their leaves w
What is condensation
The process by which water vapour changes to liquid water when cooled
What is erosion
The wearing away of the river channel by water and its load (=material carried in river)
What is abrasion.
The river carries particles of sand and moves pebbles at times of high flow. This material rubs against the bed and banks of the river and wears them away
What is attrition
The load being carried by the river collides and rubs against itself breaking up into smaller pieces and become smoother
What is solution
Some rock minerals such as calcium carbonate dissolve in river water which is sometimes acidic
What is hydraulic action
The force of the water on the bed and banks of the river it is particularly powerful in times of flood. Once material is eroded it will be transported
What is traction
Large boulders roll along the river bed needing a lot of energy
What is saltation
Smaller pebbles are bounced along the river bed picked up and then Dropped as the flow of the river changes
What is suspension
The finer sand and silt sized particles are carried along in the flow giving the river a brown appearance
What is solution
Minerals such as limestone and chalk dissolve in the water and carried along in the flow and can’t be seen
What doesn’t the amount of load in a river depend on
The volume of water (can carry more) The velocity (move larger particles) Local rock types (some are easier to erode)
Why does a river deposit sediment
When it’s volume or speed decreases I.e its energy decreases
What is the fertile material deposited by a river called
Alluvium
What are four factors that encourage deposition
- a river carries a lot of sediment = more deposition
- a reduction in velocity on the inside of a meander
- an obstruction e.g a bridge in the way
- a fall in volume of a river e.g times of low flow or drought
What are the three stages of a rivers journey
Upper, middle and lower
Characteristics of the upper course of the river
- steep v-shaped valley
- narrow/ shallow channel
- high bed load
Characteristics of the middle course of the valley
- open/ gentle sloping valley with floodplain
- wider/ deeper channel
- more suspended sediment
Characteristics of the lower course of a river
- open/ gentle sloping valley with floodplain
- flat and wide flood plain
- wide open valley
- very wide and deep channel