What are natural hazards?

Question 1

Explain the difference between a natural hazard and natural event

Answer 1

Natural Events — Floods, Earthquakes, Hurricanes, etc.

Natural Hazard — A natural event that poses a risk to property, injury and loss of life

Question 2

Common characteristics of natural hazards

Answer 2

. Clear origin and the effects they produce are distinctive e.g. earthquake cause building to collapse

. Most hazards only allow a short warning before the event

. Most losses to life and damage to property occur shortly after the event. Although the effects of the natural hazards can be felt in communities long after that (disease, disruption to communication and economic activities)

. Exposed to risk mostly involuntary in LICs, but in developed areas residents are well aware of the risks, which they choose to minimise or ignore

. Emergency response required

Question 3

Examples of Natural Hazards and Classify Them

Answer 3

. River Flooding : Hydrological

. Lightning, Cold Weather, Heatwave : Atmospheric

. Epidemic, Pests, Wildfires : Biological

. Earthquake, Tsunami : Seismic

. Lava Flow, Volcanic Gases : Volcanic

. Sink hole, Landslide : Geological

Question 4

Explain how hazards can be linked?

Answer 4

Hazards are often linked:

. Lightening (atmospheric) could lead to a wildfire (biological).

. A tsunami (seismic) is could be caused by earthquakes (seismic) or landslide into water (geological).

Question 5

Explain Human Hazard

Answer 5

Hazards that are the result of intent, error or failed systems

. 2020 California Wildfire caused by a gender reveal

. It burnt over 20,000 acres of land and destroyed 5 homes.

Question 6

How can a natural event become a natural hazard?

Answer 6

. Urban Sprawl into rural areas can result in natural events posing a risk to property and human life making it a natural hazard

For example:

  . wildfires are common in rural areas where there is more vegetation and 
    woodlands. Urban sprawl into these areas would increase the risk.

   . Dam failure (system failure) poses a risk to property and human life as it 
    involves a uncontrolled release of impounded water.

. Urban Sprawl increases the chance of human error causing wildfires. For example, a cigarette butt can cause wildfire.

Question 6

Explain how wildfires are a natural and necessary process

Answer 6

Pyrophytic plants are adapted to tolerate fire with thick bark and high moisture content

. E.g. Boabab trees ⁠— It has fire resistant bark and needs fire to open its woody fruit and seeds

Wildfires can be nature’s way of regenerating an ecosystem by killing insects and diseases that damage forests. They also promote new growth, keeping landscapes strong and healthy.

Question 7

How can wildfires be managed?

Answer 7

. Water and chemicals called retardants can be sprayed to slow the pace of wildfires

. Flames can be beaten or vegetation bulldozed to stop fires jumping

Question 8

Explain Pyrocumulonimbus (Risk of Wildfire)

Answer 8

Type of clouds generated from major wildfires.

. Clouds can generate their own weather including smoky rain, lightning and firenadoes