human impact on coastal erosion

What do sea defences do to the rate of erosion

slow down the rate of erosion

how do sea defences slow down the rate of erosion?

the sea defences slow longshore drift, trapping sediment on beaches. the beaches absorb the energy of the waves meaning they have less erosive power by the time they hit the cliffs

port construction

large concrete structures are built out into the sea, they act as groynes which trap sediment behind them this deprives the areas along from the port of sediment

why is sand and shingle important?

they absorb the energy of breaking waves and slow rates of erosion without this natural wave break the waves have more energy when they reach the cliff line

why does building on clifftops have a negative effect?

buildings add weight on the top of the cliff, as the cliff becomes waterlogged it is less likely to be able to support itself, this can cause the cliff to slump with sections sliding off into the sea

why will coastal defences be inadequate if global warming increases?

in the UK, sea walls cost between 5-10K per metre to save money, tough decisions of which areas need protection or be abandoned will need to be made

how does global warming affect the coast?

the sea will continue to rise and the number of storms and intensity will increase, meaning existing coastal defences will be inadequate and many will have to make tough decisions of which areas need protecting or be abandoned.

why does port construction affect people living near the coast?

with no shingle to absorb the energy of the waves the entire village collapsed into the sea the storm washed away all but one house

why do some people remove sediment from the seabed?

to improve access for shipping or to use sand and gravel in the construction industry