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level: River Landscapes

Questions and Answers List

level questions: River Landscapes

QuestionAnswer
What are the three courses of a river?The upper, middle and lower course.
What is erosion?The natural breakdown of material.
What is depostion?The adding and transportation of material that is then dropped off.
What is discharge?The volume of water.
What is the load?The rivers carrying capacity of sediments.
What is the cross-profile?Something that shows the shape and gradient of a valley or river's channel.
What are some features of the upper course?The source is in hills/ mountains. The river is at its highest altitude. The river is at its narrowest. The river mostly erodes and transports.
What are some features of the middle course?The river is wider. The river is getting closer to sea level. The river is at its fastest. Erosion is on the outside of meanders, and deposition is on the inside.
What are some features of the lower course?The river travels through its floodplains. The river reaches sea level. The river is at its widest. The river is at its slowest. The river deposits its sediments.
What is the Bradshaw model?A model that shows the correlation of upstream and downstream. IT shows which features are most present in certain areas.
What is lateral erosion?Erosion on the banks of a river.
Where lateral erosion more common?In the middle and lower course.
What is vertical erosion?Erosion on the riverbed.
Where is vertical erosion more common and what type of erosion causes it?Hydraulic action in the upper course causes it. The energy overcoming after deepens the channel.
What is transportation?The movement of eroded material down the river.
What are the 4 types of transportation?Traction, saltation, suspension and solution.
What is traction?Big, heavy boulders rolling along the river bed.
What is saltation?Small pebbles bounced along the river bed and surface.
What is suspension?Fine, light, eroded material moved through river waters.
What is solution?Minerals that have been dissolved in water.
How are V shaped valleys formed?In the upper course there is more vertical erosion. It deepens the river, and then weathering on the sides collapse on themselves and there's mass movement. The material builds up on the river bed which is then transported.
What are interlocking spurs?Projections of highland that alternate from the sides of V shaped valleys.
How are interlocking spurs formed?The river cuts down into the valley in the upper course, and in areas where there is hard rock that is more resistant, the river bends around it to find the easiest route.
How are waterfalls formed?The water from the source erodes the soft rock which is less resistant than the hard rock. Hydraulic action and abrasion break down the soft rock, creating a heavy hard rock overhang, and an under-cutting. The overhang then collapses on itself, and falls into the plunge pool, deepening it. The waterfall retreats and continues to erode backward, and the process repeats.
What is a gorge?A vertical, narrow, steep-sided valley that is found immediately downstream of a waterfall.
How are gorges formed?The gradual retreat of waterfalls over hundreds of years form gorges.
Explain why a waterfall is only a temporary feature on a rivers course. (4 marks)Due to hydraulic action and abrasion, the soft rock is worn away, causing an overhang of heavy hard rock which will collapse on itself and fall into a deepening plunge pool. Waterfalls will continue to erode and flatten out until the river is completely smoothed out, and the hard resistant rock is removed, which is why it's temporary.
What is a meander?A bend in the rivers course.
What erosional landform retreats upwards?Waterfalls.
Where would you find interlocking spurs?Upper course and source.
Why is there deposition on the inside of a meander?Since it's sallower where there's more friction, the river slows down and sediment is deposited.
What is an oxbow lake?A curved lake formed from a meander being cut off from the mainstream.
How are oxbow lakes formed?Erosion on the neck of the meander makes it more narrow since the river is trying to take the shortest route. Eventually the river breaks through to create a straighter route.
What is a floodplain?Flat areas of land on either side of a channel that will flood when a river bursts its banks.
How are floodplains formed?When erosion flattens out the land and gets rid of interlocking spurs.
What is an esturary?Where the river meets the sea.
What are levees?Elongated, naturally-made walls of a river. It regulates water levels and separates the river and the floodplain.
How are levees made?When heavy sediment from flooding is deposited and built up on the river banks, adding height and river discharge.
Complete the sentences using the words below. In the upper course, near the ___, the river valley is ___ and ___. This is due to ___. Landforms in the upper course include ___, ___, ___, and ___. In the lower course, near the ___, the river valley is ___ and ___. This is due to ___. Landforms found in the lower course include ___, ___, and ___. WATERFALLS; LATERAL EROSION; DEEP; INTERLOCKING SPURS; NARROW; FLOODPLAINS; LEVEES; SOURCE; MOUTH; SHALLOW; VERTICAL EROSION; ESTUARIES; WIDER; V-SHAPED VALLEYS; GORGES.In the upper course, near the SOURCE, the river valley is NARROW and SHALLOW. This is due to VERTICAL EROSION. Landforms in the upper course include V-SHAPED VALLEYS, INTERLOCKING SPURS, WATERFALLS, and GORGES. In the lower course, near the MOUTH, the river valley is WIDER and DEEP. This is due to LATERAL EROSION. Landforms found in the lower course include FLOODPLAINS, LEVEES, and ESTUARIES.
What is a hydrograph?A record of river discharge over a period of time.
What is a storm hydrograph?A graph that shows how a river changes after a storm to predict future floods.
What is the rising limb?The amount of water added to a river. If the line is steep, water is being added quickly, meaning there's a high risk.
What is the peak discharge/ flow?The maximum amount of discharge/ water.
What is the falling/ recession limb?The water levels beginning to return to normal.
What is the (basin) lag time?The amount of time it takes for the river to reach its peak discharge/ flow.
What does a short (basin) lag time mean?A great risk of flooding.
What does a long (basin) lag time mean?A reduced risk of flooding.
What is the base flow?The normal discharge of the river.
What is the bankful river discharge?The maximum amount of water the river can hold before flooding.
What is a drainage basin?The area of land drained by a major river and its tributaries.
What is infiltration?The absorption of water through soil.
What is prolocation?The absorption of water through rock.
What is a surface storage?A fully saturated area of the earth, like a pond or puddle.
Where is Sheffield?It's located in the northern central part of England, and is inland with Leeds to the north, and Stockport to the east.
What are 3 causes to floods in Sheffield?A very fast flowing river. Impermeable surfaces, causing a greater surface run-off. Rivers bursting its banks and overflowing its channels.
When was the Sheffield flooding, and what caused it?In June 2007. This may have been because the trees were removed and the soil were replaced with impermeable material, shifting it from a rural to an urban location.
What are antercedent streams?Streams that maintain their original course, despite changes in underlying rock topography.
What were 5 social impacts of the Sheffield flooding?Two people drowned. Over 1,200 houses flooded. 13,000 people were without power for 2 days. 1,000 businesses were affected. The shopping centre was closed for a week.
What were 2 environmental impacts of the Sheffield flooding?Trees were uprooted. Roads and railing links were flooded.
What were 4 economic impacts of the Sheffield flooding?1,000 businesses were affected. Hillbororugh football stadium went 8 metres under water - lots of money for repairs. Clarkson Osborn had £15M worth of damages. The shopping centre was closed for a week.
What are dams and reservoirs?Dams are concrete structures that regulate river flow and reduces the risk of flooding. It's stored in a reservoir so it doesn't flood downstream.
What is channel straightening?When rivers are straightened by cutting through meanders, speeding up the flow.
What are embankments?Raised riverbanks/ levees.
What are flood-relief channels?Man-made river channels, made to divert rivers from urban areas.
What are 2 advantages of dams and reservoirs?They're very effective at regulating river discharge. Most reservoirs can be used for irrigation, water supplies and hydro-electricity.
What is an advantage of channel straightening?They speed up the flow of water, preventing it from building it and flooding.
What are 2 advantages of embankments?They increase the total discharge, reducing the risk of flooding. It can look natural if soil, mud, stone and vegetation is used.
What are 2 advantages of flood relief channels?It's effective at regulating river discharge. During high-flowing water times, gates can be opened to allow excess water to flow, reducing the risk of flooding.
What are 2 disadvantages of dams and reservoirs?They're very expensive. People and animals have to relocate, since reservoirs flood huge areas of land.
What are 3 disadvantages of channel straightening?It's expensive. It can cause flooding downstream. It can destroy habitat and the environment.
What are 2 disadvantages of embankments?It's expensive. In urban areas, concrete is used to increase effectiveness, making it unnatural and unattractive.
What are wetlands?Land near a river that's allowed to flood.
What are 4 advantages of wetlands?They store water, so less join the channel, preventing flooding. It creates habitats. It makes areas for farming. It's cheap management.
What is the disadvantage of wetlands?The area is flooded.