Paper 1 - Coastal management strategies Flashcards
hard engineering
man made structures built to control the flow of the sea and reduce flooding + erosion
soft engineering
schemes set up using knowledge of the sea and its processes to reduce the effects of flooding and erosion
hard engineering examples
sea wall
gabions
rock armour
groynes
sea wall
barrier to flooding + erosion but it creates a strong backwash which erodes under the wall + they are expensive to build and maintain
gabions
wall of wire cages filled with rocks. they absorb wave energy to reduce erosion and are easy to build but they are ugly and corrode over time
rock armour
boulder that are piled up along the coast. they absorb wave energy and are cheap. but they can be moved around by strong waves so they need to be replaced
groynes
wooden or stone fences that are built at right angles to the coast. they trape material from longshore drift. they create wider beaches which slow the waves + theyre cheap.
but they starve beaches further down the coast of sand making them narrower
narrower beaches dont protect the coast as well making more erosion
soft engineering examples
beach nourishment and reprofiling
dune regenration
beach nourishment and reprofiling
sand is added to the upper part of the beach creating wider beaches slowing the waves but taking material from the sea bed can kill organism and is very expensive and has to be repeated
dune regeneration
creating or restoring sand dunes by either nourisment or planting vegetation. Sand dunes provide a barrier and wave energy is absorbed.
but the protection is limited to a small area and is very expensive
managed retreat (coastal realingnment)
involves removing current defences and allowing the sea to flood the land behind
over time this will become marshland which then protects land behind being flooded or eroded
its cheap and easy + dosent need maintaining and creates new habitats
it can cause conflicts though
