Flood Management Schemes

• Dams: water stored temporarily in a reservoir and regulates the rate at which water passes into the river downstream of the dam
• Embankments: artificially raised and strengthened banks enable the river channel to carry a greater volume of water. Sometimes parrallel lines of flood banks act as a double form of protection - if river rises over first, it may not be able to rise over second
• Channelisation: rivers artifically straightened with concrete - water pass more rapidly along the channel
• Channel Enlargement: involves dredging and the removal of large boulders from river bed - increases channel efficiency and reduces roughness - increases rate of flow
• Flood Relief Channels: take excess water around a settlement
• Flood storage resevoirs: excess water stored here and used for other purposes such as recreation

Slow down rate at which water enters the channel and reduces the amount of water that reaches the channel - more sustainable in long term - doesn't cause problems for the future

• Afforestation: replanting trees - slow down rate at which water reaches the river, and will reduce the volume
• Agricultural land use management: contour ploughing, leaving crop stubble in the ground over winter and ***** farming in semi-arid areas helps to reduce the amount of surface runoff - reduces liability of flooding
• Land-use zoning: using land directly next to the river for grazing and recreational activity - allowed to flood when necessary. With suffificient warning, animals can be moved to higher ground.
• Wetland and river bank conservation: Existing natural river channels and their valleys are protected so that habitats and species diversity can be maintained. 
• River restoration schemes: aim of these schemes is to return rivers to their original, pre managed state, to work with nature to improve the quality of river water.
• Forecasts and warnings

• Chang Jiang river
• world's largest dam
• 2.3km long
• >100m high
• $25 billion
• highly controversial worldwide
• essential to reducing escalating flood damage, water and power shortages
• Benefits
• water supply
• HEP replaces thermal power - environmental
• Disadvantages
• Relocation
• Loss of farmland
• Loss of cultural heritage
• Loss of social tradition 
• Increased pollution
• Habitats
• Political - war - dam a vulnerable target