1.3.3 flood management Flashcards
what is hard engineering?
involves the use of technology to alter the river flow.
what is soft engineering?
using the river’s natural features to either allow it to flood controlled or prevent it from flooding.
what is channelisation?
widens and deepens the river to increase capacity for flow volume.
what are the advantages for channelisation?
- protects immediate area
- long lasting
what are the disadvantages for channelisation?
- may lead to greater flood risk downstream as water is carried there faster
- unnatural and visually intrusive
what is a floodwall?
an artificial barrier to temporarily contain river water which may rise during certain seasons or events.
what are the advantages for floodwalls?
- can be used in areas where space is limited
- easily and quickly built
what are the disadvantages for floodwalls?
- they have to be assembled intricately
what is a dam?
water is built along the course of a river to control discharge amounts. it is held back and released in a controlled way.
what are the advantages for dams?
- water is stored and can be used to generate hydroelectric power or for recreation
what are the disadvantages for dams?
- can be very expensive
- sediment is often trapped and leads to erosion downstream
- settlements and agricultural land may be lost when the river valley is flooded
what is afforestation?
trees are planted to intercept rainfall and slow down the river flow.
what are the advantages for afforestation?
- low cost
- improves environment quality
- soil erosion is prevented
- very sustainable
what are the disadvantages for afforestion?
- often conifers are planted making the soil acidic
- dense tree plantations spoil the landscape
- fire risks due to leisure activities in the forests
what ate warning systems?
they are a network of sirens giving early warning to people for flooding.
