Soft engineering Flashcards
What is soft engineering?
Alternative to hard engineering.
Attempts to work with natural physical systems and processes to reduce coastal erosion and flood threat.
Usually less obvious and intrusive on the coast.
May be cheaper in the long term.
NOT SUITABLE FOR ALL COASTS.
What is beach nourishment?
Artificial replenishment of beach sediment to replace sediment lost in erosion, to enlarge the beach so that is dissipates wave energy and reduces wave erosion and increases amenity value of it.
What are the costs and issues of beach nourishment?
Costs of £2m per kilometer of the beach are typical.
Sediment must not be sourced from elsewhere in the local sediment cell.
What is cliff regrading and drainage?
Cliff slope angles reduced to increase stability and re vegetated to reduce surface erosion.
In-cliff drainage reduces pore-water pressure and mass movement risk.
What are the cost and issues of cliff regrading and drainage?
Costs of £1m per 100m are common.
Disruptive during construction.
What is dune stabilisation?
Fences are used to reduce wind speed across the dunes, which are then replanted with marram and lyme grass to stabilise the surface.
Reduces erosion by wind and water.
What are the costs and issues of dune stabilisation?
Dune fencing costs £400-£2000 per 100 m.
Replanting dunes costs £1000 per 100 m.
Working to maintain natural sand dunes can be very cost effective.
