What this lesson teaches
I can judge how well adaptation strategies, from technology to institutions, make a community resilient.
Syllabus K226, Topic 3.3, Key Question 4. How effective are adaptation strategies in building a community's resilience to climate change?
Make a guess
A town keeps flooding, so it builds a much bigger drain. Will that be enough on its own?
- No, probably not. Measures are needed at several points.
- Yes, so the town no longer needs flood warnings.
- No, because drains make flooding worse.
- Yes, a big enough drain stops floods of any size.
Show the answer
No, probably not. Measures are needed at several points.
A drain only acts on the flow path. Tanks that slow runoff at the source and barriers at buildings work at other points, and very big storms can still exceed the design.
Different measures tackle different parts of a problem, so combine them to fit local risks and resources.
Flood measures can act at the source, along the flow path, or at the place being protected. Tanks, ponds and permeable surfaces slow runoff at the source. Drains and channels carry water away along the path. Raised entrances and barriers protect the buildings at risk. PUB calls this the source-pathway-receptor approach.
Coastal protection includes sea walls, embankments, tidal gates and healthy coastal ecosystems such as mangroves. Designs must fit local conditions, be maintained and allow for heavy rain and high seas at the same time. Hard defences can harm habitats, erosion and access. Big events can also go beyond what they were designed for, so some risk remains.
Water adaptation combines using less with a more reliable supply. Saving water and fixing leaks cut demand. Storage, several sources and careful sharing help in dry spells. Singapore uses local catchment water, imported water, NEWater and desalination. This spreads the risk, but each source needs energy, money, maintenance and pipes.
Farming can adapt with efficient irrigation, suitable crop varieties, monitoring and controlled growing spaces. Indoor hydroponics grows crops without soil and can reuse water, sheltering crops from some outdoor weather. SFA describes its use in Singapore. Results still depend on reliable power, skills, costs and suitable crops.
Every measure has trade-offs. Irrigation eases drought but can drain water supplies. Indoor farms steady production but use a lot of electricity. A sea wall protects buildings but may harm habitats. Cost and skills decide who can use a measure. Combine technology with planning and social support, and review results as conditions change.
- Source-pathway-receptor
- Slow the water, move it, protect what is at risk.
- Singapore's water
- Catchment, imported, NEWater and desalination.
- Hydroponics
- Growing crops without soil, reusing water.
Step by step
Slow runoff
Tanks and permeable surfaces hold rainwater back.
Move and block water
Drains carry it; barriers protect buildings.
Plan for limits
Maintain defences and prepare for bigger floods.
Real examples to use
Marina Barrage, Singapore
Opened in 2008, the barrage keeps out high tides, helps prevent floods in low-lying areas and creates a freshwater reservoir.
Delta Works, Netherlands
After a flood in 1953 killed over 1,800 people, the Netherlands built a huge system of dams and storm-surge barriers.
Worked example: Food security without a false promise
An indoor vegetable farm keeps growing during a dry spell. But it depends on power, costs a lot to run and cannot grow every staple. It is one part of a mix, not complete food security.
Watch out for this
Building a flood defence means warnings and evacuation plans are no longer needed.
Defences can fail or be overtopped. People still need to prepare for the risk that remains.
Check your understanding
Why combine runoff tanks, drains and barriers at building entrances?
- Combining them removes the need to maintain each one.
- They act at different points between rain and damage.
- Each one stops heavier rain from falling on the building.
Show the answer
They act at different points between rain and damage.
Yes. Each measure tackles a different part of the problem.