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Question 1

Source

Answer 1

The start if the river

Question 2

Meander

Answer 2

A winding curve or bend of a river

Question 3

Floodplain

Answer 3

An area that us flat and vulnerable to flooding, often occurs in lower section

Question 4

Confluence

Answer 4

Is the meeting point (or junction) of where two ricers meet

Question 5

Tributary

Answer 5

Is a smaller part that eventually joins to a main river

Question 6

Drainage basin

Answer 6

An area of land where precipitation collects and drains off into a river through surface runoff

Question 7

Watershed

Answer 7

Is the boundary line between two drainage basins

Question 8

Mouth

Answer 8

When the river joins the end and flows out to a sea

Question 9

Upper course

Answer 9

Gradient is very steep, bed load sise is big, very shallow and has a high velocity (speed)

Question 10

Middle course

Answer 10

Gradient us less steep, bedload size is less big, getting deeper, less velocity.

Question 11

Lower course

Answer 11

Flat, small bedload size (fine particles), very deep, little velocity.

Question 12

Upstream

Answer 12

Gradient- steep
Bedload size- big
Channel depth- shallow
Channel width- narrow
Human activity- less

Question 13

Downstream

Answer 13

Gradient- flat
Bedload size- small
Channel depth- deep
Channel width- wide
Human activity- more

Question 14

Describe how the shape and characteristics of river channels change from source to mouth

Answer 14

Near the source of the river (upper course), the river channel will be narrow and shallow, having a big bed load size. Here the gardient is very steep which can result in the river having a high velocity. The middle course of the river the sides are often still quiet steep, the bed load size is not as big and the depth of the river increases. the gradient becomes less steep, resulting in the velocity of the river being less fast. Near the mouth of the river (lower course), the river is wider, floodplain is flat with very gentle sides, the depth of the river increases dramatically. The gradient is gentle, flat causing the velocity of the river to be slow.

Question 15

Erosion

Answer 15

means the wearing away of the landscape.

      - Abrasion: where the sand and pebbles erode the river bank and beds.
      - Attrition: where rocks ans stones wear away as they collide into each other.   - Solution: where rocks are dissolved.
      - Hydraulic action: where fast flowing water erodes the river banks.

Question 16

Transportation

Answer 16

Transportaion: is the movement of sediment by a river.

     - Suspension: very small bits of soil and rock are carriedn in the river. 
     - Traction: large rocks dragged and rolled along the river bed.
     - Saltation: smaller stones and pebbles bounce along the river bed.

Question 17

Deposition

Answer 17

Deposition: is where sediment from a river is dropped as the energy from the river is not suffiecient to carry the sediment any further.

Question 18

Causes of flooding

Answer 18

Heavy rainfall: increase in precipitation in a short period of time causes a river to over flow.

• Impermeable rock: when it does rain all the water has no where to be absored therfore it will build up resulting into flooding.
• Hard baked soil: this acts like an impermeable rock, causing a major decrease in infiltration but increase in chances of flooding.
• Steep slopes: as the slopes are very steep the water running down it has no time to infiltrate, as there is an increase in surfae run off, the watr will built up at the bottom that could result into flooding.
• Deforestation: there are not trees/plants to intercept (decrease) causing an increase in overland flow.
• Building on floodplains (urbanisation): due to the impermeable rock, water is unable to infiltrate, this increases surface fun off; the water will flow done to the river causing the levels of the river to increase which will result into flooding.

Question 19

Flood hydrographs

Answer 19

Flood hydrographs: they show the relationship between rainfall (precipitation) and how much water is in a river (discharge)

Peak discharge: the highest level of the river

Lag time: the difference between peak discharge ad peak rainfall

Peak rainfall: highest level of rainfall

Question 20

explain how human actions have increased flood risk.

Answer 20

Clearing vegetation has increased the rate of surface run off as less rainfall is being absorbed by the plants and trees as they have been cut down, this results to a shorter lag time. There would further be a decrease in interception as thos plants and trees that have been cut down are not able to interceot and absorb the rainfall. Building on a floodplain has also decreased the amount of rainfall beign infiltrated into the ground. This is beacause the water from the rainfall is unable to be infiltrated within the impermeable rock. This causes river levels to increase resulting in flooding, as it has resulted into a shorter lag time.

Question 21

Impacts of flooding

Answer 21

Impacts:

• Lose of jobs
• Damage of possessions
• Lose of stock, pets, business’
• Re-building of houses
• Decrease in tourism
• Damage of cars
• Insurance premiums went up
• Escape was hard
• People lifted to safety
• Flooded houses, ruined furniture

Question 22

Floodplain formation

Answer 22

In the lower course of the river the main process is lateral erosion and deposition. The river is carrying a very large amount of sediment. At a meander Bend the river of Rosie out the bend and the river widens. Usually it moves downstream and outwards. After time, the meander roads into the hills and creates a very fertile and flat area next to the river. This is called the river floodplain. When the river floods the water suddenly spreads out over the floodplain.Suddenly the river flows slower because friction increases.

Question 23

Levee formation

Answer 23

Floodplains and levies are formed by deposition in times of river flood. Rivers load is composed of different sized material. When a river floods it suddenly spreads out and the water slows down because affection, it deposit is the heaviest of these particles first. The larger particles, often shingle, will form the levy which is a natural material. The Sands, silts and clays are similarly sorted With the sons been deposited next, then the silhouettes and finally the smallest please. Every time the river floods deposition builds up the floodplain which is the flat land either side of the river.

Question 24

Delta formation

Answer 24

When a river reaches another body of water such as the sea or an ocean, it loses velocity and deposits sediment.If the river deposits sediment faster than coastal processes erodes it, Sediment builds up in layers in a fan-shaped Delta. The river splits into many distributaries channels called deltas and creates large areas of wet land.

Question 25

Meander formation

Answer 25

Erosion through hydraulic action and abrasion causes the outside bends to get closer together, Until there is only a small bit of land left between the bends (Called the neck)

The river breakthrough this land, usually during a flood, and the river flows along the shortest course.

Deposition eventually cut off the meander forming an ox bow lake.

Question 26

V-Shaped valley formation

Answer 26

The riverbed gets eroded much faster than the rest of the river. It is more prone to erosion.
The river has been eroded downwards due to abrasion and solution and hydraulic action. As it erodes downwards the sides of it become more unstable due to weathering and undercutting by the river. The sides want to slide into the river channel and create even more erosion.
The sides have collapsed, and the river valley has taken shape of the V shape