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River flooding and management issues

The short-term impact of floods can be catastrophic, but they can have positive long-term effects too. Watch this video to find out more.


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Key points

  • A flood occurs when a river is swollen by heavy rain. It bursts its banks and the water spills onto the flood plain.
  • Factors in the landscape can make flooding more likely. A steep-sided channel can cause fast surface run-off where the soil cannot absorb the water and so water runs over it. Rivers can flood if there are no trees and plants to catch and drink the water.
  • Floods can be catastrophic in the short term but they can have good long term effects too such as boosting soil fertility.
  • Floods tend to affect LEDCs more than MEDCs, partly because they depend on agriculture and need the fertile floodplains.
  • Hard engineering options usually cost more and have a greater impact on the river and landscape.
  • Soft engineering options are cheaper and have less impact on the environment.
  • Managed flooding is allowing one area to flood to prevent flooding towns or villages.
  • Governments and developers often prefer hard engineering options, while environmental groups prefer softer options, like planting trees. Flood management options need to be sustainable.

All Geography videos

Water and rivers index

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