4b.6 - River Management Flashcards
What is hard engineering?
Building infrastructure to manipulate / overcome challenges posed by rivers (usually involves hard materials)
What is soft engineering?
Working with nature to encourage natural processes
What are the main examples of hard river management strategies?
Flood walls, embankments, flood barriers, dams, river channelisation
What are the main examples of soft river management strategies?
Floodplain retention, river restoration, afforestation
What does floodplain retention involve?
Allowing areas of floodplain to build up and intentionally flood - this slows down river flow reaching areas of economic importance.
Planting trees also helps.
What is River Restoration?
Restoring the river to its natural course of meanders to slow the river down. Remove impermeable hard surfaces and replace with natural materials to promote infiltration.
What are embankments?
Man-made levees that are built on the side of the river
What are the main advantages (benefits) of flood walls and embankments?
Increase river capacity to hold more water and reduce flooding likelihood
What are the main advantages (benefits) of soft engineering strategies?
Environmentally sustainable to promote biodiversity, visually appealing, but also helps to promote interception and infiltration to slow the water down
What are the main disadvantages (costs) of hard engineering?
Tend to be very expensive, require maintenance, are aesthetically unappealing (ugly) and pass on the problems downstream.
What are the main disadvantages (costs) of soft engineering?
May not be an effective solution if economic value in area is high. River will naturally change anyway in future.
Where do we tend to find use of hard engineering?
Downstream near large urban areas with high economic value
Where do we tend to find use of soft engineering?
Upstream, rural areas with less economic value
