The Living World
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Managing and Mitigating Flood Risks

There are various strategies to safeguard communities from the negative effects of floods, which fall under two main categories:

  • Hard engineering strategies
  • Soft engineering strategies

Let’s explore each of these strategies.

Hard Engineering Strategies

Hard engineering strategies involve the construction of physical structures that help control and manage the flow of rivers. Although these strategies reduce flood risk, they also have their drawbacks.

Here’s a closer look at some of the most common strategies:

Dams and Reservoirs

Dams are large barriers built across rivers to control the water flow and create reservoirs that can store excess water. This prevents flooding downstream.

AdvantagesDisadvantages
Can generate hydroelectric powerExpensive to build and maintain
Reservoirs can attract touristsTraps sediment, which reduces the reservoir capacity
Can cause habitat flooding
Can potentially displace local communities, leading to loss of homes and livelihoods

River channelisation and Dredging

This involves modifying the course and depth of the river, making it more streamlined and able to carry water more efficiently. The dredging process removes sediment and debris from the river bed to deepen the channel. Making the waterway less congested allows for the easier and more efficient passage of boats and ships.

AdvantagesDisadvantages
Increased channel capacityRequires frequent maintenance
Reduces flood risk in built-up areasCan raise flood risk in downstream areas

Embankments

Embankments are raised banks constructed along the rivers to contain higher water volumes. This prevents the river from overflowing into surrounding areas during floods.

AdvantagesDisadvantages
Cost-effectiveMay appear unnatural
Prevents floodwater from overflowingCan increase flood risk downstream due to faster water flow

Flood Relief Channels

These are channels constructed to divert excess water from the main river channel. This prevents flooding in vulnerable areas and allows for the controlled release of the water downstream.

AdvantagesDisadvantages
Reduces flood risk in vulnerable areasCan be expensive to construct
Relief channels can flood in extreme situations

Soft Engineering Strategies

Soft engineering strategies are a more natural and sustainable approach to managing river flooding. These strategies aim to work in harmony with the river’s natural processes.

Flood Warnings and Preparation

Environmental agencies constantly monitor rivers and issue warnings in different ways to alert the public about potential flood risks.

These warnings are usually distributed through television and radio broadcasts, text messages, social media platforms and dedicated weather apps,

AdvantagesDisadvantages
Allows people to safeguard their properties and possessionsLimited accessibility to warnings for some individuals
Can help reduce insurance claims by minimising damage or loss of possessionsFlash floods may not offer enough time for warnings

Floodplain Zoning

Floodplain zoning involves the careful regulation and planning of land usage within areas that are most likely to experience flooding, known as floodplains.

In practice, designating specific land uses might involve restricting the construction of residential buildings in high-risk areas. It also involves encouraging agricultural use or green spaces in these zones instead, which can absorb water more readily.

Other strategies might include developing recreational parks or golf courses that are designed to handle occasional flooding without significant damage. This type of zoning helps to minimise the impact of flooding on communities, protecting lives and reducing potential damage to properties and infrastructure.

AdvantagesDisadvantages
Helps to minimise flood risks in high-value areasChanging existing land use can be challenging
Reduces potential damage and insurance claimsDetermining the appropriate level of flood protection needed in a particular area can be a complex process

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