Rivers, especially big ones, can cause a lot of chaos. When they flood, they tend to destroy livelihoods, cause economic damage and kill people. As a conclusion people then try to stop rivers from flooding using whatever resources they have. Unfortunately, rivers, like most things in nature, are powerful and unpredictable. Stopping rivers from flooding entirely isn’t possible but we can do it to mitigate and manage the risks that arise from flooding.
Flood
management is divided into two strategies, they are :-
Hard Engineering
|
Soft engineering
|
Hard engineering options
tend to be expensive, short-term options. They may also have a high impact on
the landscape or environment and be unsustainable.
|
Soft engineering options
are often less expensive than hard engineering options. They are usually more
long-term and sustainable, with less impact on the environment.
|
Hard
Engineering: -
- Is generally very successful and have a large impact on the river.
- Can disrupt ecological systems in the drainage basin
- Involves the containment of large volumes of water
- Very Expensive due to the technological requirements & maintenance
Soft
Engineering: -
they aim to work with nature to protect the coast
- Focus more on reducing the impacts of a flood rather than preventing one.
- Is significantly cheap making them more suitable for less developed countries.
- Have lower education & technology requirements so they can be applied by local people in remote parts of poor countries.
Hard Engineering Techniques
Dams:-
A dam is a giant wall built across
a river’s channel to slow down its flow.
(Artificial) Levees:-
They act as embankments to contain
a river, essentially extending the channel’s height and increasing its bank
full discharge. They are significantly large and are generally constructed out
of a material like concrete that is resistant to erosion.
Wing Dykes:-
Maintain the
control depth by effectively narrowing the river. This creates a scouring
effect, in which the river is forced to move faster, increasing its sediment
carrying capacity.
Channel straightening:-
By straightening the routes across
meanders, the river will starts to flow faster, preventing it from pooling and
so reducing the risk of a flood.
Diversion Spillways:-
They are artificial channels that
a river can flow into when its discharge rises.
Soft Engineering Techniques
Floodplain Zoning: -
This
strategy organizes land that is near the river and often floods to be used for
farming. However, the areas that rarely get flooded are used used for housing,
transportation and industry.
Afforestation:-
Afforestation involves the
planting of trees. This reduces a river’s discharge and so makes it less likely
to flood.
Wetland Restoration:-
Wetland restoration involves
creating conditions that are favorable for the development of wetlands. This helps
reduce the discharge in a river. This
restoration increases the biodiversity and reduces the area of land.
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