About natural hazards

This section gives background information about natural hazards in Aotearoa New Zealand and how they can affect our health.

Natural hazards in New Zealand

New Zealand is susceptible to a range of natural hazards. Due to its geography and location, New Zealand is prone to a range of natural hazards, including earthquakes, volcanoes, erosion, landslides, and extreme weather events. Flooding is the most common natural hazard in New Zealand and earthquakes and tsunamis are potentially the most damaging and disruptive [1].


How to natural hazards affect health?

Natural hazards can affect our health in several ways. They can affect us directly through trauma and injuries, and potentially death. They can also affect us indirectly, through contaminated drinking-water supplies, particulates in the air, exposure to hazardous substances, displacement and disruption, and impacts on mental health [3].

Diseases and illness are more likely to spread when important infrastructure and services such as water, sewerage, and electricity are disrupted. For example:

  • Salmonellosis and campylobacteriosis can occur through eating contaminated foods
  • Communicable diseases such as influenza and measles can spread through poor emergency accommodation and overcrowding
  • Diseases spread by animals (such as leptospirosis) can also become more prevalent
  • Lack of medicines, particularly prescription medicines can increase the risk of illness such as diabetes, asthma or chronic obstructive pulmonary disease (COPD).

People's vulnerability to natural hazards is affected by their exposure to the hazard, their susceptibility (based on their age and health status), and their resilience to natural hazards.


Climate change will likely increase the risk from natural hazards

Climate change is also likely to increase the frequency and intensity of extreme weather events, particularly flooding, storm surges, and drought. According to the latest climate projections for New Zealand [2], we are likely to experience:

  • higher temperatures
  • rising sea levels
  • more frequent extreme weather events
  • changes in rainfall and wind patterns
  • more drought
  • increased fire risk.

Climate change can affect health in a number of ways, including:

  • direct impacts, eg physical injuries or deaths caused by weather itself; heat stroke
  • indirect impacts, eg water-borne diseases, salmonellosis, respiratory problems, mosquito-borne diseases
  • diffuse impacts, eg mental health issues.

The rise in population and land intensification also increases the potential severity and consequences of future natural hazard events.

See relevant information in the climate change section of the website.


Who is more at risk of health impacts?

People who are most at risk from natural hazards and climate change are generally our most vulnerable populations [4, 5]. These include:

  • infants and children
  • elderly
  • people with a chronic health condition or disability
  • low socioeconomic status groups.

Other population groups may also be more at risk, depending on the hazard and circumstance. These population groups include Māori, Pacific peoples, people of other ethnic minorities, people living in urban areas, people living in rural areas, and people working in certain occupations.  

People may also be more vulnerable if they have a lack of resilience, particularly in the areas of having enough money to cope with crises/losses; social connectedness; knowledge, skills and awareness to face hazards; safe, secure and healthy housing; enough food and water to cope with shortage; and decision-making and leadership.

Read more about the population groups more at risk from environmental hazards on the 'who is more at risk' webpage

Read more about social vulnerability indicators for natural hazards, pandemics and other emergencies on the 'Social vulnerability indicators for natural hazards' webpage



1. MCDEM (2007). National Hazardscape Report. Officials’ Committee for Domestic and External Security Coordination Department of the Prime Minister and Cabinet, Wellington, New Zealand

2. NIWA (2016). 'Seven-station' series temperature data. National Institute of Water and Atmospheric Research. Accessed 21/08/2017 at https://www.niwa.co.nz/our-science/climate/information-and-resources/nz-temp-record/seven-station-series-temperature-data

3. Royal Society New Zealand (2017). Human health impacts of climate change for New Zealand – Evidence Summary. Accessed 19/07/2018 at https://royalsociety.org.nz/assets/documents/Report-Human-Health-Impacts-of-Climate-Change-for-New-Zealand-Oct-2017.pdf

4. DANIDA. 2000. Who Suffers? Identifying the Vulnerable Groups. Paper presented at the DANIDA Workshop Papers: Improving the Urban Environment and Reducing Poverty, Copenhagen, Denmark.

5. Hudson J, Hughes (2007). The role of marae and Maori communities in post-disaster recovery: a case study. GNS Science Report 2007/15, 51p



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