Karteikarten
Rivers
Karten in diesem Stapel (41)
- 1What is dischargeThe rate at which a river carries water along its course
- 2Identify four factors that influence the velocity of a river?Gradient
Discharge
Shape of channel
Roughness of river channel - 3What are the processes of erosion?Hydraulic Action - cavitation
Abrasion
Attrition
Solution - 4What is the name for the material transported in a river?Load
- 5What is the name for soil deposited by a river?Alluvium
- 6Identify four ways a river transports load?Solution
Suspension
Saltation
Traction - 7How do fluvial processes deposit load?Deposition is stratified/graded/sorted by size and weight
- 8When is deposition likely to happen along the course of the river?When speed is reduced
When discharge is reduced
When load is increased
When a river flows into a lake, or sea - 9What is a drainage basin?The area of land drained by a river
- 10What is a watershed?An imaginary line around the upper part of the drainage basin that shows the upper point from which water flows into the river
- 11Explain the words: Source, Course, MouthSource; The place where the river begins
Course: the route taken by the river from source to mouth
Mouth: The place where the river enters a sea or lake - 12Explain Tributary and confluence?a stream or river that joins a larger river
A place where two or more rivers meet - 13What is an Estuary?The part of a river's course that is tidal
- 14Identify three stages of the riverUpper/Youthful
Middle/Mature
Lower/Old age - 15Identify the contour pattern at each stage?Upper: tucked in
Middle: fewer lines broad curve
Lower: Absence of lines, flat floodplain - 16How does the direction of flow change along the course?Upper, straight line
Middle: some meanders
Lower: wandering meanders - 17How is a narrow V shaped valley formedVertical erosion deepens the channel
The steep sides collapse due to weathering and mass movement
The river washes away the load
The process repeats - 18How do Interlocking Spurs form?Youthful rivers wind around hard rock
Vertical erosion deepens the valley
Eventually spurs of land slope down across the valley - 19What are potholes?small landforms in the uneven bed of the youthful river
Swirling water turns in an eddying action dragging stones and creating holes by abrasion - 20The Waterfall. Landform of ErosionExample: Torc Waterfall, Co. Kerry//
- 21Where are Waterfalls found?A waterfall is a feature of erosion usually found in the upper course of a river valley where the gradient is steep and the youthful river is full of energy.
- 22How does differential erosion lead to the formation of waterfalls?The river passes over alternating layers of soft and hard rock eroding the hard rock slowly but eroding the soft rock down river of the hard rock more efficiently in a process called differential erosion.
- 23Rapids are found upstream of a waterfall. What are rapids?The river passing over the hard rock is carrying little load, the bed of the river is uneven and the flow of water is turbulent and rapid, in this way rapids occur.
- 24What is a knickpoint?When the river comes into contact with a soft rock layer it uses saved energy to erode the soft rock and a drop called a knickpoint is formed.
- 25What is the main process of erosion active in the formation of a knickpoint?The main process at this stage is hydraulic action which is the sheer force of running water as it rushes into any joints or weakness in the rock forcing out any loose material and washing it away.
- 26What other process(es) are active at this time?Solution can also be effective at this stage as rocks such as limestone react chemically with water, which is a mild acid. In this way a drop is formed.
- 27How does gravity aid hydraulic action?As the water cascades over the drop it gains force due to gravity. Again hydraulic action helps to deepen and widen the hollow beneath the drop.
- 28How does abrasion aid the process of erosion?The load in the river falls into the hollow. The rocks in the load strike off the bed of the hollow deepening and widening it further. This process is called abrasion
- 29How does the process called solution aid the formation of a waterfall?As the water falls, a fine spray splashes onto the back wall of the drop and solution is active again in breaking down the back wall in a process referred to as rot.
- 30How does the Coriolis Effect influence the formation of a waterfall?The water in the hollow turns in a circular movement called an eddying action, due to the Coriolis Effect. In this way further abrasion occurs.
- 31How does attrition aid the formation of a waterfall?The load rubs off itself being broken down in a process called attrition. In this way the load is made smaller and moved down river, which enables the river to erode more rock.
- 32What is a plunge pool?The deep and wide hollow beneath a waterfall is called a plunge pool.
- 33What is headward erosion, in the formation of a waterfall?The back wall of the waterfall is undercut making the lip of the fall overhang in an unstable way. Overtime the wall will collapse into the plunge pool due to gravity and hydraulic action/abrasion will be used to break it down and wash it down river.
- 34Explain how headward erosion creates a gorge?In this way a waterfall retreats up river in a process called headward erosion. Headward erosion causes the river to deepen its valley towards its source creating a gorge in front of the waterfall
- 35How is a waterfall a temporary landform?A waterfall is a temporary feature that through the processes of erosion explained above removes itself from the landscape.
- 36Explain how Isostasy, changes in land level relative to sea level can form waterfalls?Waterfalls can occur when isostatic changes occur. When the land is uplifted the process of deposition in the old stage of the river may change to processes of erosion. Such a river is said to be rejuvenated. Waterfalls may form at these new knickpoints
- 37Examine how glaciation process may result in the formation of waterfalls?When a glacier moves down a valley it removes the lower sections of tributary valleys by plucking and abrasion creating truncated spurs and hanging valleys. The rivers in these side valleys now cascade over the truncated front of the valley.
- 38Identify one landform associated with the middle stage of a river?A meander - up to an Oxbow Lake
An alluvial Fan in the channel
Braiding in the channel - 39Identify the landforms of deposition in the lower stage of the river?Floodplains
Levees
[Oxbow Lakes]
Deltas - 40Identify four drainage patterns found in rivers?Dendritic drainage pattern
Trellis drainage pattern
Radial drainage pattern
Deranged drainage pattern - 41How do people interact with river processes?Flood control systems
Navigational aids
Hydroelectric Power - Dams
Irrigation and Agriculture
Informationen
- Beschreibung
- Junior Certificate Geography Karteikarten am Rivers, erstellt von Patrick O Sullivan am 09/03/2017.
- Erstellt von
- Patrick O Sullivan
- Aufrufe
- 6
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