What are the different types of coastal management?
Revetments £1,000/m Open structure of planks absorb wave energy, but allow sand and shingle to build up beyond Are these attractive? Hard engineering
Rock armour or Rip Rap Relatively cheap £1,000/m, but considered environmentally ugly When resting on sand and shingle they may be moved out of position by waves
Expensive at £5,000/m Designed to stop erosion, but what landforms would that prevent being created? Would you rather go on holiday and see Old Harry or a sea wall? Sea Walls Energy is reflected (not absorbed). Over time the energy scours the base of the sea wall undermining it, causing it to collapse This is reduced by absorbing the energy and angling the wall
Gabions Much cheaper than sea walls £1000/m, but do you think they are attractive? Small rocks, bound in place by cages absorb the wave energy and reduce erosion
Stop longshore drift What are they designed to do? Further down the coast this may mean that beaches are starved of sand and shingle Groynes £10,000 each (wooden groynes) £1.5m each (rock groynes) Mappleton, Yorks. coast
Gabions and groynes together Why might you choose to implement more than one coastal management strategy at a time? To protect against erosion and longshore drift
“ Soft” Engineering Less expensive than hard strategies Longer term, more attractive and sustainable as they work with natural processes How attractive do you consider these to be?
Beach Nourishment The beach is widened; how will this affect the energy of the waves? Sand and/or pebbles are brought in to replace material that has eroded away. Where do you think this replacement material has come from? It has been dredged from the sea bed. In some cases it is pumped onto the shore. It will reduce the energy that the wave has meaning less erosion. Cost: £100/m/yr
Stabilising Sand Dunes Grasses are planted in the sand dunes to bind them together, holding them in place. Footpaths may be designated. Why might this be? To reduce trampling of the dunes by people, which erodes them
Managed Retreat When the land by the sea is of low economic value it may be allowed to erode. In some cases this eroded material forms beaches which naturally protect the coast.