4a-human activity intentionally causing change Flashcards
what is curved sea wall and how does it impact the coastline
curved sea wall- deflects waves and reduces wave topping, prevents flooding
what is rip rap and how does it impact the coastline
rip rap- large angular boulders, that absorb wave energy, decrease erosion and flooding
what is revetments and how does it impact the coastline
revetments- makes backwash loose energy, increases deposition
what is groynes and how does it impact the coastline
groynes- reduce sediment moving along the beach by LSD by trapping it, builds the beach profile
what is beach replenishment and how does it impact the coastline
beach replenishment- sediment put on the beach acts as a buffer to erosion and increases tourism
what is managed retreat and how does it impact the coastline
the coastline is left undefended so land is flooded creating a slat marsh with protects land further in.
at Porlock bay has meant that more erosion and that sediment moves onto the shore
at The Warren (golf course) - there is less sediment there due to it being stopped by the groynes so less inputs into the system and erosion will take sediment out of the system and LSD is removing the sediment so no longer absorbing the wave energy
what effect did doing nothing at selworthy cliffs have on the coastline
system is the same but some may be eroded providing sediment for places further along the coast, erosion over a long period of time could lead to cliff collapse.
what consequences has there been due to management strategies in minehead/porlock
Porlock bay suffered a loss of sand and a salt marsh was created.
Selworthy cliffs have wave-cut notches that could lead to cliff retreat in the long term as well as a shore platform
Minehead- less erosion leads to more sediment on the beach so it will be longer and higher. expensive- sea wall cost £12.3mill
at the golf course wave erosion means the beach will be smaller
