B. Physical Geography and Physical Processes in Canada · Canada's Physical Environment: Landforms, Climate, Hazards and People

Living With Hazards: Risk, Vulnerability and Ways of Responding

B2.3 A2.3 A1.5About 75 minutes

Learning goals

I can explain risk as a combination of hazard, exposure and vulnerability.
I can analyse why some communities and people face greater risk from the same natural event.
I can describe structural and non-structural ways of responding to hazards at each stage of the disaster management cycle.
I can assess responses to hazards using criteria such as effectiveness, cost, fairness and environmental impact.

Words to know

risk
The chance that a hazard will cause harm; it depends on the hazard, exposure and vulnerability.

exposure
The people, buildings and things of value that are located where a hazard can reach them.

vulnerability
How easily people or things are harmed by a hazard, because of factors such as building quality, age, health, income or isolation.

resilience
The ability of a community to prepare for, cope with and recover from a hazard.

mitigation
Actions taken before a hazard to reduce its impact, such as building a floodway or restricting building on floodplains.

structural response
A physical, built response such as a dike, floodway, seawall or earthquake-resistant building.

non-structural response
A response based on planning, rules, information or behaviour, such as zoning, warnings, insurance or emergency plans.

floodplain mapping
Maps showing which land is likely to flood, used to guide where building is allowed.

evacuation
Moving people out of a dangerous area to safety.

Same storm, different stories

Two neighbourhoods get the same heavy rainstorm. In one, homes on high ground stay dry and everyone has power. In the other, homes in a low area beside a creek flood; some residents are older people living alone, some rent basement apartments, and some do not have flood insurance or a car to leave. The rain was the same. The risk was not.

Expectation B2.3 asks you to analyse the risks that physical processes and natural events present to communities in Canada, and to assess ways of responding. This lesson gives you the tools.

Risk = hazard × exposure × vulnerability

Hazard: how likely and how strong the event is (a 1% chance flood; a magnitude 9 earthquake).
Exposure: who and what is in the way (homes on a floodplain; a town surrounded by forest; a coastal highway).
Vulnerability: how easily they are harmed. Factors include:
Physical: old or poorly built buildings, basements in flood zones, one road in and out.
Social and economic: age (very young and older people), health and disability, income (can people afford insurance, repairs, a car to evacuate?), language barriers, social isolation.
Geographic: remoteness. Many northern and fly-in communities, including many First Nations, have only one airstrip or a winter road, so evacuation and supplies are harder.

Capacity (plans, resources, knowledge, strong community networks) reduces vulnerability and builds resilience.

Risk is a combination of three factors. You can reduce risk by reducing any one of them, for example, by keeping homes off floodplains (exposure) or by making buildings stronger (vulnerability).

The disaster management cycle

Emergency managers think in a cycle:

Mitigation: reduce the impact before anything happens (floodways, building codes, keeping development off floodplains).
Preparedness: plans, warnings, emergency kits, drills, training.
Response: during and right after the event: evacuation, rescue, shelters, firefighting.
Recovery: rebuilding and supporting people afterward, ideally "building back better" so the next event does less harm.

Responses can be structural (built things) or non-structural (rules, plans, information, behaviour). The best strategies usually combine both.

The disaster management cycle. Every recovery is a chance to improve mitigation for the next event.

Canadian responses: case studies

1. Winnipeg and the Red River Floodway (structural, with a perspective twist). After a major flood in 1950 forced the evacuation of a large part of Winnipeg, Manitoba built the Red River Floodway, a huge channel that carries flood water around the city. It opened in 1968 and was expanded after the 1997 "Flood of the Century". It has protected Winnipeg from serious flooding many times. Towns elsewhere in the valley built ring dikes. But flood control has trade-offs: in 2011, water management to protect some areas sent extra water into Lake Manitoba and Lake St. Martin, and several First Nations, including Lake St. Martin First Nation, were flooded out and many residents were displaced for years. Asking who is protected and who bears the cost? is part of the geographic perspective.

2. Ontario after Hurricane Hazel (non-structural). In October 1954, Hurricane Hazel caused deadly flooding in the Toronto area, especially where homes had been built in river valleys. Afterward, Ontario's conservation authorities mapped floodplains, bought land in valleys, and restricted building there. Many of Toronto's ravine parks exist because of this decision. Ontario's approach of steering development away from floodplains is still a key mitigation strategy.

3. Wildfire and the 2016 Fort McMurray evacuation. In May 2016, a wildfire forced the evacuation of about 88 000 people from Fort McMurray, Alberta. The evacuation along one main highway showed both the importance of planning and the vulnerability of communities with limited road access. Programs such as FireSmart Canada help communities reduce risk: clearing flammable material near homes, using fire-resistant roofs and creating fuel breaks.

4. Earthquake preparedness in B.C. British Columbia has upgraded (seismically retrofitted) many schools, uses earthquake-resistant building codes, and holds the yearly ShakeOut drill. Natural Resources Canada runs the Canadian Earthquake Early Warning system (launched in B.C. in 2024, and in parts of Ontario and Quebec in 2025), which can give seconds to tens of seconds of warning before strong shaking arrives.

5. Knowledge for safe travel in the North. Inuit hunters have deep knowledge of sea-ice conditions passed down through generations. As climate change makes ice less predictable, Inuit-led programs such as SmartICE combine that knowledge with sensors and maps to help people travel more safely.

A floodway carries extra water around a city during floods (schematic, not to scale). Gates control how much water enters the channel.

Everyone's part: warnings and kits

Alert Ready sends emergency alerts to TV, radio and compatible cell phones in Canada for dangers such as tornadoes, floods, wildfires and other threats to life.
The Government of Canada (GetPrepared.ca) recommends that households be ready to take care of themselves for at least 72 hours in an emergency, with a plan and a kit including at least 2 litres of water per person per day.

Worked example

Modelled example: Who is most at risk?

A spring flood is forecast for a river town. Rank these households from highest to lowest risk and explain: (A) a family in a new house on a hill with two cars; (B) an older person living alone in a basement apartment next to the river, without a car; (C) a family in a riverside house with sandbags, flood insurance and a plan to stay with relatives.

Hazard is the same for all three (the same flood).
Exposure: B and C are beside the river (high); A is on a hill (low).
Vulnerability: B has many vulnerability factors (basement unit, age, living alone, no car). C has reduced vulnerability through preparation, insurance and a place to go.
Rank: B (highest), then C, then A (lowest).

Highest risk: B; then C; lowest: A. Two households with the same exposure (B and C) have different risk because of vulnerability and capacity.

Worked example

Worked example: Assessing response options with a decision matrix

A town is choosing how to reduce flood risk. Score each option from 1 (poor) to 3 (good) on four criteria and total the scores.

Option 1: build a dike. Effectiveness 3 (protects existing homes); Cost 1 (expensive); Fairness 2 (protects those behind it, but may push water toward neighbours downstream); Environment 1 (cuts the river off from its floodplain). Total 7.
Option 2: buy out the most at-risk homes and turn the land into a park. Effectiveness 3 (people are out of harm's way); Cost 2; Fairness 2 (fair if owners are paid properly and helped to move, but hard for families attached to their homes); Environment 3 (restores the floodplain). Total 10.
Option 3: warnings and education only. Effectiveness 1 (saves lives but not property); Cost 3 (cheap); Fairness 2; Environment 3. Total 9.
Reflect: scores depend on judgement and on who is asked. Different groups would weight the criteria differently. Combining options (buyouts plus warnings) may be best.

With these scores, Option 2 (buyouts and parkland) ranks highest, but the matrix is a tool for discussion, not a final answer. A real decision would include residents and the local First Nation or Métis community, if any, in setting the criteria and weights.

Criterion	Question to ask
Effectiveness	How much does it reduce harm to people and property?
Cost	What does it cost to build and maintain? Who pays?
Fairness (equity)	Who benefits, and who bears the costs or risks? Are vulnerable groups protected?
Environmental impact	Does it harm or restore ecosystems?
Sustainability	Will it still work as the climate changes?

Criteria for assessing ways of responding to hazards (B2.3).

Hands-on activity

Make a 72-hour family emergency plan and kit list

You need: paper and a pen, a grown-up, the GetPrepared.ca checklist (online), a backpack or bin if you decide to assemble the kit.

Know the risks: list the two or three hazards most likely where you live (use the last lesson).
Make a plan: decide a meeting place near home and one outside your neighbourhood; choose an out-of-town contact; note where the water shut-off and electrical panel are (a grown-up handles these).
Kit list: water (at least 2 L per person per day, for 3 days), non-perishable food and a manual can opener, flashlight, a battery-powered or crank radio, extra batteries, first aid kit, medications, copies of important documents, cash, phone chargers, warm clothes, and items for pets or babies if needed.
Check: does anyone in your household need special supplies (glasses, hearing aid batteries, mobility aids)?
Explain which stage of the disaster management cycle this activity belongs to.

What to look for: a realistic, specific plan; the student identifies preparedness as the stage. Grown-up note: adults should handle utilities, medications and any candles or fuel; flashlights are safer than candles.

Just for fun

Why did the flashlight get the top spot in the emergency kit?

Everyone agreed it was the brightest idea.

Your turn

What three factors combine to create risk?

Give three factors that can make a person more vulnerable to a flood.

Name the four stages of the disaster management cycle.

Is a floodway a structural or non-structural response? Is floodplain mapping?

Why did Ontario restrict building on floodplains after 1954?

Give one benefit and one cost of the Red River Floodway.

How much water does GetPrepared.ca recommend per person per day in an emergency kit?

More practice: warm-up

What is mitigation?

About how many people were evacuated from Fort McMurray in 2016?

What is Alert Ready?

What does FireSmart help communities do?

What does "build back better" mean?

More practice: on your own

Why might a remote fly-in First Nation be more vulnerable to wildfire smoke or floods than a city of the same size, even with the same hazard?

Classify each as mitigation, preparedness, response or recovery: (a) seismic retrofit of a school, (b) an evacuation, (c) a 72-hour kit, (d) rebuilding homes on higher ground.

Explain why combining structural and non-structural responses is usually better than relying on one.

How does an earthquake early-warning system reduce harm if it gives only seconds of warning?

Choose one Canadian case study from this lesson and explain how it shows the geographic perspective.

Challenge

Redo the decision matrix for the town flood problem, but this time give "Fairness" double weight (multiply its score by 2). Does the ranking change?

A city plans to build a dike that will protect a wealthy neighbourhood but may raise flood levels downstream, where a lower-income community lives. Assess the plan using at least three criteria.

Use the risk equation to explain why the same magnitude 7 earthquake would cause very different harm in a remote part of Haida Gwaii and in downtown Vancouver.

Check your understanding

Quiz

Which formula best describes risk?

Building a floodway is an example of:

Ontario restricted building on floodplains after:

Which household is most vulnerable to a flood?

A 72-hour kit is part of which stage?

Which question checks the FAIRNESS of a response?

What does the 2011 flooding of Lake St. Martin First Nation show?

For parents and teachers

Big idea: B2.3 asks students to analyse the risks physical processes and natural events (including disasters) present to Canadian communities and to assess ways of responding. The risk equation and decision matrix give your teen tools to move beyond describing disasters to evaluating responses. A2.3 (current events) fits naturally: news about floods and fires is frequent.

Sensitive content: This lesson mentions real disasters and displacement, including the long displacement of Lake St. Martin First Nation after 2011 flooding. Discuss these respectfully, focusing on causes and responses, and recognizing that the effects on communities are real and ongoing. The joke in this lesson is only about the emergency kit.

Common difficulties:

Thinking risk is only about the hazard. Use the "same storm, different stories" example.
Treating a decision matrix as an exact answer. It organizes judgement; scores and weights are debatable.

How to help: Make the family emergency plan together and actually put the kit together. Check your municipality's emergency page and sign up for alerts. Talk about which neighbours might need help in an emergency.