Hard & Soft Engineering Rivers & coasts Flashcards
What are concrete levees
-artificial levees built up to raise the river banks
What are overflow channels
Channels built close to normal channel for when it overflows
What are dams and reservoirs
Big dam innit
Water flow can be controlled and let out when needed (in the reservoir behind the dam)
What is afforestation
-replanting trees and greenery
-intercepts 70% of rainfall
- cheaper than hard engineering (takes a long time to grow)
What is floodplain zoning
-Land in a river valley planned out based on flood affects
-decreasing building space
-increasing green zones
What is river restoration
-removing hard engineering to restore the river
-creates wetland (new habitats) potential loss of farmland
What is a sea wall pros&cons
Concrete wall
-give tourists a place to walk
-expensive,ugly
What is rock armour pros&cons
Large boulders piled up
-relatively cheap, quick
-boulders need to be large and erosion resistant
Groynes definition pros&cons
Wooden fences built at a 90’ angle to the beach
-relatively cheap
-starve coastline further down of sand
Gabions definition pros&cons
Large steel cages filled with rocks
-last 20-30 years
-hazardous if not replaced
Beach nourishment definition pros&cons
Sand added back to the beach
-little environmental impact
-needs to be replaced regularly
Dune regeneration definition pros&cons
Artificial sand dunes at back of the beach
- cheap, new coastal ecosystems
-take several years to establish
