Textbook Solutions: River Flooding | IGCSE Oxford Geography Foundations for Year 6 - Class 6 PDF Download

What causes a river to flood?

Q1. a. Make a larger copy of drawing E.

b. Add the following labels to your drawing to show how a river floods:

River level rises

Water quickly reaches river

River floods

Water runs over surface

Heavy rain falls

Rain soaks into ground

Ans:

Q2. Describe four factors that increase the risk of flooding.

Ans: 

Four factors that increase the risk of flooding:

1. Prolonged Rainfall: When it rains for a long time, the soil can become saturated, meaning it’s full of water and can’t absorb any more. This leads to more water running off the surface into rivers, which can cause flooding.

2. Heavy Rainfall: Intense rain can lead to water arriving too quickly to soak into the ground. This increases surface run-off, which means water reaches the river channel faster and can lead to a higher risk of flooding.

3. Geology: The type of ground can affect flooding. Impermeable surfaces like clay don’t let water soak in, which leads to more water running off into rivers and potentially causing floods.

4. Relief: The shape of the land can influence flooding. Steep slopes can make water flow quickly into rivers, which increases the chance of flooding.

Q3. With the help of diagram F, describe how:

a. cutting down trees, and

b. building towns can make floods worse.

Ans: 

a. Cutting Down Trees (Deforestation): Trees are like nature’s sponges; they soak up water with their roots. When trees are cut down, there’s nothing left to absorb the extra water, so it just flows away, which can cause flooding. Trees also help hold the soil together, so without them, the soil can wash away, which also contributes to floods.

b. Building Towns (Urbanization): When we build towns, we add lots of hard surfaces like roads and buildings that water can’t soak into. This means that when it rains, the water runs straight off these surfaces and into rivers, which can cause them to overflow and flood. Plus, building towns often means getting rid of plants and trees that would normally help absorb the water

Floods in the UK, 2012

Q1.

a. When did the flooding around York happen?

b. Which river flows through York?

c. Which three other rivers drain the area?

d. Which settlements were affected by flooding?

e. What are the names of the two upland areas?

Ans: a. The flooding around York happened in late September 2012. 

b. The river that flows through York is the River Ouse. 

c. The three other rivers that drain the area are the River Nidd, River Wharfe, and another river not clearly mentioned in the text. 

d. The settlements affected by flooding include York, villages to the south of York, Barlby, and Selby. 

e. The names of the two upland areas are the Pennines and the North York Moors. 

Q2. Make a larger copy of drawing D and add six causes

of the 2012 flood.

Ans: 

Q3. Describe the effects of flooding in York using the newspaper headlines shown in E.

Ans: 

• Record flood levels swamp York: The city of York experienced unprecedented flood levels, with the River Ouse reaching heights not seen in centuries, causing widespread inundation.
• Problems continue as flood waters recede: Even after the floodwaters began to recede, the city faced significant challenges in terms of clean-up and recovery efforts.
• Families hit as floods wreck homes: Many families suffered as their homes were damaged or destroyed by the floods, leading to loss of personal belongings and the need for temporary housing.
• Flood havoc hits commuters: The flooding disrupted transportation, with roads blocked and rail services canceled, affecting daily commuters and travel within the region.

How does the UK cope with floods?

Q1. a. Describe three ways that the Environment Agency can help reduce the risk of flooding.

b. Describe three ways that the Agency can help limit the worst effects of flooding.

Ans: 

Ways the Environment Agency can help:

a. Reduce the risk of flooding:

1. Maintaining watercourses: The agency can regularly clear rivers and streams of debris to ensure smooth water flow and prevent overflow.
2. Building flood defenses: Erecting barriers like levees and flood walls can protect areas from rising waters.
3. Natural flood management: Restoring wetlands and other natural sponges can help absorb excess rainwater and mitigate flooding.

b. Limit the worst effects of flooding:

1. Flood warning systems: Implementing advanced warning systems can alert residents early, giving them time to prepare or evacuate.
2. Flood-proofing properties: The agency can advise on modifications to buildings to make them more resistant to flood damage.
3. Community engagement: Organizing local flood warden schemes and developing community flood plans can help prepare residents for floods.

Q2. Which flood warning would have been given for the York floods of September 2012 (pages 38 and 39)? Give reasons for your answer.

Ans: Flood warning for York floods of September 2012: Given the severity of the situation, with record river levels and extensive property damage, the most appropriate flood warning would likely have been a “Severe Flood Warning,” which indicates a danger to life and serious disruption to community services.

Q3 . 'Floodline' encourages people to make a family flood plan like the one opposite. Write out the plan and add a reason for each point.

Ans: 

Family flood plan:

1. Know your flood risk: It’s important to be aware if your home is in a flood-risk area.
2. Sign up for flood warnings: Getting alerts can give you crucial time to act.
3. Prepare a flood kit: A kit with essentials like food, water, and medication can be a lifesaver.
4. Make an evacuation plan: Knowing where to go and how to get there can keep you safe.
5. Protect important documents: Keeping documents dry and secure can save a lot of trouble.
6. Learn how to turn off utilities: This can prevent further damage to your home.
7. Have an insurance check: Ensuring you’re covered for floods can help with recovery costs.

How can the risk of flooding be reduced?

Q1. Draw a star diagram to show eight ways of reducing the risk of flooding. Write a short sentence to describe each one.

Ans: 

1. Forests: Planting trees in the drainage basin can slow down water movement and reduce the amount reaching the river.
2. Embankments: Building up river banks with earth or concrete can deepen the river and prevent overflow.
3. Dams: Constructing a dam can trap water in a reservoir, allowing for controlled release to manage river levels.
4. Concrete Linings: Lining urban river channels with concrete can quickly direct excess water away from populated areas.
5. Straight Channels: Straightening the river course can speed up water flow, reducing the risk of local flooding.
6. Wider and Deeper Channels: Dredging the river bed and banks can increase the river’s capacity and lower flood risk.
7. Overflow Channels: Creating overflow channels can divert excess water to the sea or storage lakes when levels rise.
8. Allow Flooding: Controlled flooding in designated areas can reduce pressure on other parts of the river system.

Q2. Look at the different approaches to flood prevention. Which approach do you think:

a. costs most

b. costs least

c. may drown farmland and houses

d. uses up most land

e. protects the natural environment?

Give reasons for your answers.

Ans: a. Costs most: Building dams is typically the most expensive due to the large scale of construction and maintenance required. 

b. Costs least: Allowing natural flooding in safe areas is usually the least costly as it requires minimal intervention. 

c. May drown farmland and houses: Dams can lead to the drowning of land upstream, affecting farmland and houses if not properly planned. 

d. Uses up most land: Allowing flooding or creating overflow channels can use up significant land to provide safe flooding areas. 

e. Protects the natural environment: Planting forests is beneficial for the environment as it supports ecosystems and biodiversity. 

Q3. One approach to flooding is simply to allow rivers to flood naturally. For each of the people below say if they would be for or against this method. Give reasons for your answer.

Ans: 

• Environmentalists: Likely for, as natural flooding can restore wetlands and natural habitats.
• Farmers: Likely against, as it could flood their land and ruin crops.
• Homeowners: Against, due to the risk of property damage.
• Urban Planners: Mixed; some may be for it if it protects urban areas, others against due to unpredictability.
• Insurance Companies: Against, as frequent claims from flood damage could be costly.
• Government Officials: Mixed; some may support it for environmental reasons, others against due to public pressure and economic impacts.

The river flooding enquiry

a. Copy table A which shows some factors that have to be considered when choosing a flood protection scheme.

b. Look carefully at the map and scheme descriptions. Show the advantages of each scheme by putting ticks in columns A, B, C or D. Complete one factor at a time. More than one column may be ticked for each factor.

c. Add up the ticks to find which scheme has the most advantages.

d. Which scheme would you choose? The one with the most advantages would be the best. If two schemes are equal, think about which parts of the valley you would want to protect most. 

e. Briefly describe the scheme you have chosen. Explain how it will help protect the valley from flooding.

Ans: 

a. Table A - Factors to Consider:

b. The advantages of each scheme are marked with ticks based on the descriptions provided.

c. Schemes C and D have the most advantages with 7 ticks each.

d. Chosen Scheme: Scheme D

• Scheme D seems to offer a balanced approach, being quite cheap and allowing for natural flooding in less critical areas while protecting Crofton.

e. Scheme D Description:

• This scheme involves building embankments at Crofton and modifying the river to take water away quickly. It allows for natural flooding downstream at river bends, which can help maintain ecological balance. It’s cost-effective and minimizes the impact on homes and farmland.

Q2. The flood protection scheme will affect different people in different ways. Work in pairs and discuss what the people in the drawing below will think of your chosen scheme. For each person say if they would be for or against the scheme.

Give reasons for their views.

Ans: 

 Perspectives on Scheme D:

• Trudy Trout: Likely against, as her caravan park could be at risk if located upstream where flooding might still occur.
• Barry Beer: For, assuming the Crofton Inn is protected by the embankments, his business would be safe from flooding.
• Farmer Wally Wade: Mixed; if his farm is upstream, he might be against due to potential flooding, but if it’s in Crofton, he might be for it.
• Larry Laugh: Likely for, as improved flood defenses could mean fewer disruptions to roads, aiding his driving routes.