Changing Landscapes Of The Uk - Rivers

Question 1

Mass movement

Answer 1

The movement of rocks and soil downslope due to gravity

Question 2

Soil creep

Answer 2

Individual particles of soil move slowly down a slope

Question 3

Sliding

Answer 3

Material moving rapidly down a slope in one go e.g landslide

Question 4

Flows

Answer 4

Masses of rocks moving downslope as they mix with water and flow like a liquid

Question 5

Deposition

Answer 5

When a river no longer has enough energy to carry its load (material) so drops the material the process of material being dropped by the river

Question 6

Transportation

Answer 6

A river picks up and carries material as it flows downstream

Question 7

Hydraulic action

Answer 7

Air is forced into cracks in rocks in the river,forcing rocks apart

Question 8

Attrition

Answer 8

Rocks and pebbles in the river crash into each other, causing the rocks to become smoother and smaller

Question 9

Abrasion

Answer 9

Rocks in the river crash into river banks and are dragged along the river bed causing erosion like sand paper

Question 10

Solution

Answer 10

Acidity in the river dissolves soft rock

Question 11

Weathering

Answer 11

The breakdown of rocks at or near the surface by natural processes (usually on the river valley sides)

Question 12

Biological weathering

Answer 12

Living things, such as the roots of trees,breaking soil and rocks apart

Question 13

Chemical weathering

Answer 13

Rainfall is slightly acidic therefore it dissolves softer rocks

Question 14

Mechanical weathering (Freeze-thaw)

Answer 14

Water that’s has seeped into the cracks of rocks as it freezes it expands in volume by 9% in volume cracking and forcing the rock apart it is repeated until the rock splits in two

Question 15

Saltation

Answer 15

Small rocks are bounced along the river bed

Question 16

Suspension

Answer 16

Small sediments are carried in the river (held up) downstream

Question 17

Solution (transportation)

Answer 17

Small grains of sediment are dissolved and carried down the river downstream

Question 18

Traction

Answer 18

Large boulders being rolled along the river bed downstream

Question 19

point bars

Answer 19

Point bars are made up of the deposited material that accumulates on the inside bend of a river meander.
They are crescent-shaped, are very gently sloping and found below the slip-off slope.
They are made of alluvium.

Question 20

levees

Answer 20

Levees are piles of sediment that form at the side of river channels after repeated flooding.

Question 21

mouth

Answer 21

the end point of a river where it meets the sea or ocean

Question 22

levee

Answer 22

a raised bank of sediment along the side of a river

Question 23

waterfall

Answer 23

a flow of water falling from a height into a plunge pool

Question 24

source

Answer 24

the starting point of a river

Question 25

confluence

Answer 25

the point where two rivers meet

Question 26

gorge

Answer 26

a steep narrow valley with rocky sides

Question 27

meander

Answer 27

a bend in a river caused by erosion and depostition

Question 28

tributary

Answer 28

a small stream or river that joins a larger one

Question 29

drainage basin

Answer 29

A drainage basin is the area of land around the river that is drained by the river and its tributaries.

Question 30

oxbow lake

Answer 30

A horse-shoe shaped lake left after the necks of meanders meet

Question 31

floodplain

Answer 31

the flat fertile land in a valley next to a river that often floods

Question 32

watershed

Answer 32

the boundary between the drainage basins

Question 33

interlocking spurs

Answer 33

Pieces of land that over lap , they are hills that a river meander around in a V shaped valley. When viewed from downstream these spurs appear to be locked together

Question 34

How are meander formed and oxbow lakes

Answer 34

Outside of a river flows at high velocity, causing lateral erosion, inside slower so material deposits forming a point par. Literalersonion eveuntially becomes curved process continues creating a meander

Oxbow lake

During flooding the river takes a straight past From neck of mender this eroded material eventually. Creating a slight line . This forms an oxbow lake

Question 35

How are waterfalls formed?

Answer 35

Band of Gand rock positioned above exposed soft rock, less resistant rock is eroded creating and over a hand. After more erosion over hang falls forming a plunge pool
A steep suedes gauge is formed at side and a waterfall where it originally was

Question 36

River dee and its long profile

Answer 36

Located in snow Donna wales flows east into England its mouth is located in Chester

Upper - steepest - waterfalls etc

Middle - widens, menders

Lower- flood plains , levee

How is the river Dee important
Import t water source for newly 3 million people

Provides habitats for. Range of animals

Flows through areas f natural bath

Physical changes to river Dee-
Drought
Climate through the yer is variable in UK, and rainfall influences river flows. During drought, river flows are low, however , when rainfall is high , river flows r high. This causes erosion to church

Question 37

Causes and effects of flooding

Answer 37

Flooding first of all is when a river bank bursts and overflows onto the nearby land

What causes flooding
Heavy rainfall
Narrow shallow rivers
Blocked drain
Building houses on Floodplains

Roads impeable water rushes Ito river

Physical Causes
Duration of rainfall

Intense rainfall
Rocks- imprarmable
Relief- water reaches river channel much faster where stopes are steeper as water travels faster

Snow melt- in high altitude areas, snow falls during inter. When temp rise in summer, this snow melts and causes rivers to flood

Human
Deforestation- trees and plant intercept water
Urbanisation- more concrete Tamra

Climate change- extreme weather more common. So more storms and rainfall

Impacts- Cumbria flood in Workington

Social
1 death- PC Bill Barker
50 people had to be rescued from their homes
25 bridges destroyed or loses due to damage
1300 homes flooded in Cocker-mouth and Workington

Economic-
Cockermouth high street was completely flooded, forcing businesses to close
3057 businesses were affected in some way

Total cost was over £270 million

Environmental- river derwents course was changed by erosion

Question 38

Flood Defences

Answer 38

Soft Enineering

Washlands- areas on flood plain that are allowed to flood

Pros
Give safe place fo floodwater to go
Improves rivers natural sedimentation processes

Cons
Allowing land to flood limits usage of the land

River restoration
Restoring the rivers original course
Pros
Slows river down

Natural rivers are more attractive

Cons
Some flood banks are often still needed

Floodplain zoning
Locating more areas of land to different uses, according to their level of old risk

Pros
Flood risk management aims to recent homes and businesses and high risk zone.
Such as open space for leisure
Cons
May not be best places of activities in terms of public access Italy

Flood plains are attractive places to build on

Hard engineering

Embankments(levees)- high banks built on river banks

Pros
St pater from spreading into areas where it could cause problems- such as housing

They can be earth and gras banks which blend in with the environment

Cons
Flood may still go over to- water can be trapped behind them

Can burst under pressure, possibly causing even greater damage

River Channelisation
Deepening or strengthening the river

Pros
This allows more water to floe

Cons -
Water taken ownstream may put ther places at risk
Does not look natural

Flood relief channels- extra channels built next to the river-
Can accommodate high flow of water

Cons
May not be needed often
May be unsightly

Dams and reservoirs
Long lasting ad can also be used to produce hep

Cons expensive and can cause displacement of people

Question 39

What is river discharge

Answer 39

the volume of water flowing through a river channel; measured at any given point in cubic metres per second.