Flood risk management is a key focus in IB Geography, particularly within Option A: Freshwater – Drainage Basins. Flood risk management refers to the methods used to reduce the likelihood of flooding and minimise its impacts on people, property, and the environment. These strategies can be broadly divided into hard engineering, soft engineering, and planning-based approaches.
Hard engineering strategies involve large-scale construction designed to control river flow and reduce flooding. One common example is dams and reservoirs, which store excess water during periods of high rainfall and release it gradually. This reduces peak discharge downstream and lowers flood risk. However, dams are expensive, can displace communities, and may disrupt ecosystems and sediment flow.
Embankments and levees are another hard engineering method. These raised river banks increase channel capacity and prevent rivers from overflowing into surrounding areas. While effective in protecting specific locations, embankments can increase flood risk downstream by speeding up river flow. If they fail, flooding can be sudden and severe.
Channelisation involves straightening and deepening river channels to increase flow speed and capacity. This reduces flooding locally but often transfers risk downstream and damages river habitats. In IB Geography, students are expected to evaluate both the benefits and limitations of hard engineering solutions.
Soft engineering strategies work with natural processes rather than controlling them. Floodplain zoning restricts development in high-risk areas, reducing exposure to flooding. This approach lowers damage costs and preserves natural flood storage areas but may limit land availability for housing or industry.
Afforestation and river restoration help reduce flood risk by increasing interception, infiltration, and natural storage. Planting trees stabilises soil and slows runoff, while restoring meanders increases channel length and reduces flow velocity. These strategies are more sustainable and environmentally friendly but take time to become fully effective.
Flood warnings and preparation are also important soft engineering methods. Early warning systems allow people to evacuate, protect property, and prepare emergency responses. While they do not prevent flooding, they significantly reduce loss of life and economic damage.
Planning-based approaches include integrated flood management, which combines multiple strategies at the drainage basin scale. This approach recognises that flooding cannot be completely prevented and focuses on reducing risk through coordinated land use planning, engineering, and community involvement.
In IB Geography, strong answers recognise that no single strategy is sufficient. Effective flood risk management requires a combination of hard and soft engineering tailored to local physical and human conditions.
Overall, flood risk is best managed through sustainable, long-term strategies that balance protection, environmental health, and social needs.
RevisionDojo helps IB Geography students evaluate flood management strategies clearly, supporting balanced analysis and high-quality exam responses.
