First 322 words of the document:
River Management Schemes
This involves the use of methods such as:
- Artificially raising levees (e.g. urban areas)
- Dredging (= boats used to transport silt off the river bed)
- Dams (e.g. Aswan Dam)
- Straightening of rivers to control river rates
- Aggradation of beds build up of material along the riverbed to raise the
- Diversionary channel one method to avoid flooding (pulling water away)
The Mississippi River is a major river covering almost half of the United States.
The river used to flood arid and the channel moved around the floodplain. This
made navigation difficult so people attempted to manage the river. Strategies
involved dykes, levees, dams and river straightening (the Mississippi is
arguably the most engineered rivers in the world). This solved the flooding
problem, as the river flowed faster over a shorter distance. In 1993, the
management techniques faded, and large areas were flooded. People now
question whether or not we can actually control natural processes.
Recent solution involved the Morganza Spillway brought into action in May
2011, to ease pressure on the Baton Rouge and New Orleans, where worst
floods occurred since the 1920s.
Key Features: - Soft engineering is a lot more sustainable
- Softer approaches are mainly concerned with flood abatement = reducing the
possibility of flooding by managing land-use upstream (e.g. afforestation,
contour ploughing, planting vegetation to reduce bare earth)
Providing flood warning schemes: - bicycles and megaphones in Bangladesh
- "Floodline" in the UK (Environment Agency send message to warn)
River Restoration Scheme returns rivers to a more natural state with the aim
of reducing flooding and improving natural environments so that plants and
wildlife are encouraged to return.