Landslides
The consequences of landslides can be considerable, even irreversible, especially when they occur in populated areas. They can affect the health and well-being of the population, even causing death, as well as leading to destruction or damage to infrastructure and loss of land and natural resources.
Quebec has experienced a number of landslide events over the past century. Examples include one in Notre-Dame-de-la-Salette in 1908, which claimed 33 lives, and one in Saint-Jean-Vianney in 1971, with 31 fatalities. In July 1996, during the Saguenay flood, more than 1,000 landslides were recorded in less than 36 hours. They killed six people. More recently, in the summer of 2023, the Rivière-Éternité landslide led to the evacuation of many residents and boaters as well as the death of two people.
Health and well-being
Landslides can have an impact on health and safety, and even threaten people’s lives.
Some of the consequences of a landslide are immediate, such as death, while others occur after the event, such as injuries during clean-up operations.
Some impacts may be short-lived, such as physical injuries. Others, such as post-traumatic stress disorder, may develop slowly or appear after some time.
That said, the health effects of landslides are poorly studied on a Canada-wide scale. This can be explained by the fact that the mortality rate caused by landslides is significantly lower than that associated with other medical causes or events, such as road accidents.
Safety threat
When landslides occur in populated areas, they can lead to emergency evacuations and rescue operations. In such cases, people’s daily lives can be severely disrupted, with negative impacts on their mental health.
Infrastructure
Landslides can damage transportation infrastructure such as roads and bridges.
They can wash away or obstruct these structures, causing major disruption to transportation and public services. Residential and community buildings are also at risk of collapse in the event of a landslide.
Costs associated with landslides
Landslides can cause major economic losses. Damage to infrastructure and private property can lead to considerable costs for individuals, businesses and governments. In addition, the disruption to economic activity caused by these events can cause a reduction in productivity and revenue.
However, the costs associated with landslides are difficult to calculate. Although data is not available for Quebec, it is estimated that across Canada, they have cost billions of dollars over time. Annual costs can reach between $100 and $200 million. These are largely invested in rebuilding due to damage.
Environmental impact
Landslides can also cause significant environmental damage. Soil erosion can occur, vegetation can be destroyed, and the movement of materials and debris can pollute nearby watercourses. These effects can have both short- and long-term consequences for local ecosystems.
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