paper 2 dont know Flashcards
why rock type affects rate of erosion
- differnces in softness
- joints/cracks
one reason why some coasts are protected
different value
eg diff land uses
agriculture is less valuble
sedimentary rocks
other rocks
soft less resistant
form lowland landscapes
reason for increase in storm freq
climate change
warm water generates energy in atmosphere more storms
2 reasons for land use change
deindustrialisation - move from industry
accessibility improves so price increase = more commercial
why cities attract international migrants
high paid + high skilled jobs due to TNC headquatres - fill knowledge economy
how migration changed population
- diversity - tension in community
- distinctive areas form
- cultural mixing can increase
2 reason inner city functions change
- deindustrialisation - decreases industry
- globalisation - TNCs - growth of finance sector
one strategy for urban living
congestion charge
decreases pollution
how wave height effects erosion
more water = more energy - more erosion/ destructive wave
^ hydraulic action
how to form deltas
When approaching the mouth, rivers are carrying huge amounts of fine sediment in suspension. On reaching the sea, the river velocity may suddenly be reduced, and flocculation occurs which causes vast amounts of deposition. Occasionally, this occurs in the main channel and blocks the river flow. The river then must divide into smaller channels called distributaries to reach the sea. Overtime the deposited material may build up and outwards to form a delta. Tidal areas are submerged by the sea twice a day, so salt marshes form
levee formation
As a river in the lower course floods, it loses its velocity and begins to deposit its sediment load. Levees (raised banks) are made of the coarse river load which is the first to be deposited when the river flood, finer sediment is deposited fast, furthest from the river channel.
oxbow lake formation
as ,the meander grows more and more over time until it becomes a very tight loop known as a meander cut off. When the water level is very high, the river had enough energy it go straight across the loop, rather than around it, since it is a quicker route. The river keeps to its new channel, so the loop is left as an oxbow lake
interlocking spurs
Interlocking spurs are found mainly in the upper course of the river, where the geology is mainly harder rock. Due to the river’s lack of energy and the resistance of the rock, the river does not waste energy trying to overcome these obstacles and instead takes the easiest path – this means it bends around the harder rock that protrudes into the V-shaped valley of the upper course. Any leftover energy is used as hydraulic action to deepen the channel through vertical erosion, assisted by gravity.
why soft engineer not hard engineer
One reason why soft engineering methods are often preferred is their cost. Hard engineering methods such as flood barriers have very high construction costs and require regular maintenance. In contrast, soft engineering methods such as river restoration have far lower up-front costs and need minimal maintenance. Another reason why soft engineering is often favoured is appearance. Hard engineering strategies such as flood walls often look very unnatural and ruin views. However soft engineering adds very little construction and focuses on natural methods so maintains natural appearances and rarely spoils view.