G3: Distinctive Landscapes Flashcards

Question

What are the characteristics of a river’s upper course?

Answer 1

``` ● Narrow ● Steep ● Shallow ● Slow-moving ● High friction ● low discharge ● Erodes Vertically ```

Answer 2

``` ● Wide ● Gentle ● Shallow ● Fast-moving ● Low friction ● High discharge ● Erodes laterally ```

Answer 3

● Water erodes rock vertically (due to gradient) ● Weathering weakens channel walls ● Mass movement forces material into the channel, which is transported away ● A V-shaped valley is left

Answer 4

● A layer of Hard rock lies over soft rock. ● The soft rock erodes away faster ● H.A. and abrasion undercut the back wall, forming an overhanging ledge of hard rock ● Falling upstream material drills downwards into the soft rock and forms a plunge pool ● The unsupported ledge falls & is eroded away, causing the waterfall to retreat ● Constant retreat leaves a gorge behind

Answer 5

● Is composed of the hard rock Whinstone (Or dolerite) and the soft rock Limestone ● Marks the rivers drop from 301+ metres of height range to the 61-300 metres of height range

Answer 6

``` ○ Inside ● Water flows slowly ● There is more friction ● Water loses its energy & deposits sediment ● A gentle slip-off slope forms ○ Outside ● Water flows quickly ● There is less friction ● More erosion (abrasion) occurs ● A steep river cliff forms ○ This means meanders migrate and expand in the direction of the river cliff over time. ```

Answer 7

● Because water flows in a Corkscrew fashion, the river bends ● Increased erosion on the outside of bends forms a meander ● The meander expands, and erosion at the neck of the meander slowly narrows it ● During flooding, the river will break through the meander’s neck, forming a straight channel ● Deposition will occur at the meander bends, eventually sealing the meander off and forming an Ox-Bow lake

Answer 8

● Meanders in the lower course erode laterally at the river cliff, causing them to migrate. ● This migration widens the river valley ● When the valley floods, sediment in the river is deposited at its banks as the river loses energy due to friction ● As the area repeatedly floods, piles of debris and material with steep side form on the edge of the river, called levees. Furthermore, fine alluvium is deposited on the valley floor to build up and create floodplains

Answer 9

Soft engineering is a way of maintaining a coastline by working with natural processes, whereas hard engineering works against them

Answer 10

● Hold The Line: The coastline is kept constant ● Advance The Line: The coastline is expanded ● Managed Retreat: The coastline is allowed to retreat at a controlled rate ● No Active Intervention: Take no action

Answer 11

● Sand & Shingle beaches, formed by the eroding of glacial Till ● Blakeney Spit & Marshes, formed by longshore drift ● Steep cliffs, formed by Mass movement

Answer 12

○ Climate Change ● Warmer oceans mean stronger storms and rapid erosion ● Coastlines withdraw, beaches starve and cliffs slump ↳ 6m of Blakeney spit was lost in a 2013 storm surge ↳ This has and will lead to the damage of property, such as the Sea marge hotel, which will be lost by 2055 ○ Geology ● Area primarily composed of soft rock deposits, underlined by chalk & formatted of Glacial Till/Boulder Clay ↳ Means erosion is rapid & deposition is high

Answer 13

● Management is Hold the line in many areas ↳ In areas of managed retreat, coastal erosion is 1m per year ● Overstrand implements... ↳ 9 Groynes ↳ 900m of Sea wall ↳ Gabions ↳ Revetments ● Current coastal erosion in hold the line areas is 0m per year ● Last building lost was in the 1940s ● In the future, there will be a shift from hold the line to Managed retreat ↳ Under this, 60 buildings, including the Sea marge hotel, will have been lost by 2105

Answer 14

``` ○ Sea wall ● Reflect wave energy, long lifespan ● Expensive, require maintenance, unattractive ○ Groynes ● Retain beach access ● unattractive, can become starved of sediment ○ Gabions ● Cheap, efficient ● Unattractive, short lifespan ```

Answer 15

● Source is in the cotswold hills, 100m above sea level ● No upper course features ● Primarily runs over oxford clay, an impermeable rock

Answer 16

● There was twice as much rain as expected for 3 months due to storms [CLIMATE] ↳ The ground was saturated, reducing infiltration ↳ Water levels in the Thames were high ● Urbanisation reduced infiltration ● Deforestation reduced water interception ● Ground is impermeable clay [GEOLOGY] ● The creation of the Jubilee river increased water velocity & quantity downstream in Wraysbury & Staines

Answer 17

● Thousands evacuated ● £500 million in repairs required ● 5,000 homes & businesses flooded in Wraysbury & Staines

Answer 18

● Volunteers & Boat owners assisted in evacuation ● Specialist equipment for damage prevention was lent out by organisations for free ● The Thames Barrier, 520 metres in width, was closed off, preventing water from the sea's high tide from contributing to the flooding ● In the future, housing built in flood-prone areas will... ↳ Have Water-filled green corridors as a feature ↳ be built on raised land ↳ Have vegetation to reduce water infiltration ↳ Have relief that naturally directs water into creeks

Answer 19

● Impale two stakes into the ground on each bank and stretch a tape measure between them ↳ Stakes must be vertically straight ↳ Tape must be taught ↳ To avoid slant, both tape fixings must be on the same horizontal level

Answer 20

● Take measurements using a metre stick at set intervals, either every metre or every eleventh of the river's total width ↳ Have the metre stick vertically straight ↳ Have the metre stick parallel to the water flow ↳ Avoid large rocks & debris (set intervals highlights anomalies)

Answer 21

● Place two equivalent poles 10m apart down a river. ● Use a clinometer at the further down pole and point it at a marking on the further up pole. Measure the angle of the gradient ↳ Avoid large drops in the river bed ↳ Poles must be the same length

Answer 22

● Method One ↳ Use a flowmeter to take measurements at a 1/4, 1/2 & 3/4 ways across the river's width ↳ Take 6 measurements at each, holding for 10 seconds each time ↳ Hold the flowmeter stationary to get water velocity alone ↳ Do not make contact with the floor ● Method Two ↳ Place a bright & visible float in the water & measure the time taken for it to flow ten metres downstream

Answer 23

River Discharge = River width x River depth x River Velocity