Flood Management

Read the following summary from BBC:
Flood managementSteps can be taken to manage flooding. Often these involve trying to lengthen the amount of time it takes for water to reach the river channel, thereby increasing the lag time. Flood management techniques can be divided into hard and soft engineering options.
'Hard' options tend to be more expensive and have a greater impact on the river and the surrounding landscape. 'Soft' options are more ecologically sensitive. The tables summarise the main flood management techniques.

Hard engineering options:
Dam constructionDams are often built along the course of a river in order to control the amount of discharge. Water is held back by the dam and released in a controlled way. This controls flooding.
Water is usually stored in a
reservoir behind the dam. This water can then be used to generate hydroelectric power or for recreation purposes.
Building a dam can be very expensive, and sediment is often trapped behind the wall of the dam, leading to erosion further downstream. Settlements and agricultural land may be lost when the river valley is flooded to form a reservoir.
River engineeringThe river channel may be widened or deepened allowing it to carry more water. A river channel may be straightened so that water can travel faster along the course.
The channel course of the river can also be altered, diverting floodwaters away from settlements.
Altering the river channel may lead to a greater risk of flooding downstream, as the water is carried there faster.

Soft engineering options:
AfforestationTrees are planted near to the river. This means greater interception of rainwater and lower river discharge.
This is a relatively low cost option, which enhances the environmental quality of the drainage basin.

Managed flooding (also called ecological flooding)
The river is allowed to flood naturally in places, to prevent flooding in other areas - for example, near settlements.

PlanningLocal authorities and the national government introduce policies to control urban development close to or on the floodplain. This reduces the chance of flooding and the risk of damage to property.
There can be resistance to development restrictions in areas where there is a shortage of housing.
Enforcing planning regulations and controls may be harder in LEDCs.

Views on flood management techniques
Governments and developers often favour large hard engineering options, such as dam building. Building a dam and a reservoir can generate income. Profits can be made from generating electric or leisure revenue.
Environmental groups and local residents often prefer softer options, such as planting trees. This causes little damage to the environment and does not involve the resettlement of communities.

Read Users' Comments (2)

2 Response to "Flood Management"

  1. CMax, on August 13, 2010 at 3:11 AM said:

    Good points made. I believe China is adopting more of the "soft" approach refered to in the article. Moldova may have to do the same. Thanks, CMax

  2. sant, on December 13, 2010 at 4:43 AM said:

    very good piece of work written. this is sure to help me with my GCSE's