32.1: Types of Disasters
By the end of this section, you should be able to:
- Describe different types of disasters, differentiating between natural and human made.
- Discuss health and safety hazards of disasters and public health emergencies and how they affect people and communities.
- Assess conditions to identify disasters or public health emergency risks, including a community’s vulnerability to a disaster.
The word “disaster” can elicit feelings of anxiety, dread, and fear. A disaster is any occurrence that causes destruction, human injury, or loss that overwhelms the community’s available resources. The number and impact of disasters rise each year. In 2022, 387 disaster events occurred worldwide. These events affected 185 million people, caused 30,704 deaths, and resulted in $223.8 billion in economic damage (Centre for Research on the Epidemiology of Disasters [CRED], 2023). As disasters become more common globally, people are more sensitive than ever to discussions of disasters. Advanced communication methods can instantaneously disseminate news to social media outlets, inundating individuals with a constant flow of information and graphic details of the aftermath of disasters. Seemingly “small” incidents may quickly develop into a disaster if resources such as supplies, equipment, personnel, or any other reserves necessary to provide care and recovery during a serious event are unavailable or are depleted quickly. For example, if only one emergency responder arrives without supplies or equipment on the scene of a single car accident with four victims, this could be viewed as a disaster until appropriate resources are dispatched and arrive to assist.
Public health or community health nurses play a key role in reducing a disaster’s impact. They help assess a community’s disaster risk, coordinate and participate in preparedness activities, and aid in disaster response/recovery efforts to maximize available resources and minimize loss. A solid disaster prevention, preparedness, response, and recovery plan is key to the community’s ability to emerge stronger and healthier if a disaster occurs.
Disasters are categorized into two main types: natural and human made. Each type has the potential for human, material, economic, or environmental losses with short- or long-term effects on the community.
Natural Disasters
Natural disasters are those that arise from forces of nature, such as weather events (hurricanes, tornadoes, snowstorms, heat waves, lightning, thunderstorms, and droughts), geological events (mudslides, floods, landslides, and avalanches), underground events (tsunamis, earthquakes, and volcanic eruptions), or epidemiological events (communicable disease outbreaks or swarms). Some natural disasters occur gradually or can be predicted, allowing communities to prepare for the event. However, many natural disasters occur suddenly and are unpredictable, causing significant public health risks to communities (Figure 32.2). Destruction and devastation from natural disasters have risen astronomically throughout the world over the past 40 to 50 years (U.N., 2021; White House, 2022). Floods, droughts, severe storms, hurricanes, and heat waves have caused 80 to 90 percent of all documented natural disasters since 2013 (World Health Organization [WHO], 2023b). The WHO (2023b) has attributed the number of weather-related natural disasters in recent years to increased weather extremes resulting from climate change. See Environmental Health for more information on the effects of climate change .
Natural disasters cause widespread destruction and health risks within communities. This video describes the 10 most dangerous natural disasters.
Watch the video, and then respond to the following questions.
- What are common causes of landslides?
- Where is the most tornado-prone area in the world?
- Why are earthquakes rated the most dangerous natural disaster?
Flooding, when excess water overwhelms normally dry land, is the most common natural disaster. Floods may result from heavy rainfall, rapid snowmelt, or a storm surge from a hurricane or tsunami in coastal areas and can cause widespread devastation, loss of life, and damage to property and critical public health infrastructure (WHO, 2023b). In 2022, a reported 176 floods affected over 57 million people globally, resulting in more than 7,000 deaths and $44.9 billion in economic losses (CRED, 2023). There are three common types of floods:
- Flash floods are caused by heavy or excessive rain falling over a short time span, often less than 6 hours. Flash floods cause raging torrents that raise water levels quickly, sometimes overtaking roads, clearing away everything in their path.
- River floods occur when excessive rainfall or snowmelt forces a river to exceed capacity.
- Coastal floods are caused by storm surges associated with hurricanes and tsunamis. Storm surge is an abnormal rise of water generated by a storm, over and above the predicted astronomical tides (National Oceanic and Atmospheric Administration [NOAA], n.d.-b).
Tornadoes and hurricanes are characterized by high wind speeds and thunderstorms that can produce violent weather conditions, resulting in property destruction. Tornadoes and hurricanes have similar devastating effects, such as high winds and water accumulations from rainfall, but each has its own distinctive dangers (Emergency Planning, 2017). Tornadoes are usually short-lived but have violent rotational winds of 100 to 300 miles per hour that extend from thunderstorms that come into contact with the ground (NOAA, n.d.). Often these storms are visible from miles away. Hurricanes occur in tropical climates. They are typically much larger storms than tornadoes and can span long periods of time in one area. This increases rainfall accumulation and makes the area more prone to flooding or storm surges. Hurricanes differ from tornadoes in that they have more sustained winds of at least 74 miles per hour rather than rotational winds. Based on the speed of the sustained winds, hurricanes are rated on a scale from one to five. The higher the rating, the greater the storm’s potential for damage. While there have been advancements in storm predictions, there is no guarantee of safety in tornadoes, so the threat of tornadoes and hurricane activity should always be taken seriously (NOAA, n.d.-a, n.d.-c). Tornadoes can spawn from hurricanes, thereby increasing the risk of damage to life and property.
Human-Made Disasters
Human-made disasters are directly caused by people’s actions that devastate and destroy human life. Examples include warfare (acts of terrorism and biological warfare), mass violence , shootings, industrial accidents, and nuclear/radiation incidents. Such disasters can be intentional or accidental, but they are always a result of human activity or neglect that causes damage to or loss of life or property.
Human-made disasters can be divided into three categories:
- Technological disasters , also known as Natural Hazards Triggering Technological Accidents ( NA-TECH ) disasters, are technological accidents triggered by natural events. Often, technological accidents are foreseeable and preventable if the associated risks are managed responsibly and warning signs are not ignored (Krausmann & Necci, 2021). Examples include industrial accidents such as chemical spills, transportation accidents, and mining accidents.
- Social disasters : Examples include warfare, genocide, civil unrest, and terrorism.
- Environmental disasters : Examples include deforestation and wildfires due to arson.
Two well-known technological disasters are the Deepwater Horizon oil spill and the Chernobyl nuclear accident. Both were avoidable accidents resulting from systematic failures and human neglect. The morbidity and mortality of human and ecological life from both events were high and continue to have long-standing effects.
The Deepwater Horizon oil spill began with the explosion and sinking of an oil drilling rig in the Gulf of Mexico on April 20, 2010, resulting in the deaths of 11 workers and the largest offshore oil spill in the history of marine oil drilling operations. The accident dumped 134 million gallons of oil into the Gulf of Mexico over 87 days (EPA, 2022). The effects of the oil spill spanned 1,300 miles of shoreline along five U.S. states, killing thousands of marine life, birds, and sea turtles and contaminating their natural habitats (NOAA, 2017). This environmental contamination altered the marine ecosystem, thereby reducing the availability and sustainability of a major source of the U.S. seafood supply until the restoration of the ecosystem is complete.
On April 26, 1986, in a part of the former Soviet Union that is now Ukraine, a nuclear reactor in the Chernobyl Nuclear Power Plant exploded, causing fires and releasing radioactive material that contaminated the immediate area and many parts of Europe. The disaster resulted from a flawed reactor design operated by inadequately trained personnel. Two Chernobyl plant workers died in the explosion, and 28 people died from acute radiation syndrome within the following weeks. Long-term health effects from the disaster include approximately 5,000 cases of thyroid cancers, 15 of which resulted in fatalities (World Nuclear Association, 2022). Radiation fallout from the disaster was carried by wind and storm patterns over much of the northern hemisphere, although the amounts were insignificant in many cases (International Atomic Energy Agency, 2023).
On February 3, 2023, a train carrying toxic chemicals derailed in East Palestine, Ohio. The derailment caused chemical contamination of the ground, water, and air. Following this disaster, some community members evacuated the area and sold their homes, while others evacuated and have since moved back.
Watch the video, and then respond to the following questions.
- What was the immediate response to the trail derailment?
- What were the immediate impacts of the derailment on the community? How might the community be impacted in the long term?
- What methods were used to clean up the toxic chemicals in the ground, water, and air?
Examples of social disasters include warfare and terrorism, such as the Russian invasion and occupation of parts of Ukraine on February 24, 2022, which was a major escalation of the Russian-Ukrainian War that began in 2014, and the Boston Marathon bombing on April 15, 2013. Social disasters result in the loss of human life, physical and mental injury, damage to the local economy, and destruction of property, infrastructure, and environment. Social disasters may also give rise to social-political issues and civil unrest, impacting not only the local community but also the national and global community.
Environmental disasters are devastating events affecting an area’s ecological system that destroy wildlife and pose a significant threat to humans. Wildfires are one example. In U.S. history, of the 58 wildfires considered the most destructive, almost 28 percent were attributed to arson—fires set intentionally. The community impact of these deliberate acts includes the destruction of 6,500 homes and businesses, 50 fatalities, and the devastation of one million acres of forests (Prell, 2017).
Wildfires cause destruction of local life, property, infrastructure, agriculture, environment, and economy and displacement of the local population and wildlife. Additionally, the smoke from wildfires spreads hundreds of miles, affecting air quality. The video describes the impact of wildfires on humans.
Watch the video, and then respond to the following questions.
- How did the wildfires in this video impact local residents?
- Who is most vulnerable to reduced air quality due to wildfires?
Public Health and Safety Hazards of Disasters
Disasters pose significant health and safety risks at the community and individual levels, especially for vulnerable populations. Understanding the breadth and depth of the impact on communities and vulnerable populations requires the consideration of direct and indirect health effects. Risk factors are dynamic and can change based on social and political circumstances surrounding the disaster (Khorram-Manesh & Burkle, 2020).
Impact of Disasters: Communities
The direct impact of disasters on community health may include large numbers of injuries and deaths that overwhelm the local emergency response services and health systems. Damage to the health services infrastructure, roads and transportation, and communication systems; reduced resources, such as available health care staff; and increased need for additional equipment can impede health care providers’ abilities to care for victims in the immediate response. It also affects the provision of follow-up care, which may have negative consequences for morbidity and mortality in the community. A significant risk of communicable diseases from a contaminated water supply, deceased animals, standing water, or other environmental factors may exist. Overcrowded health care facilities or living conditions compound the risk of infectious diseases. Food and water shortages pose a significant threat to the population, especially if the community is geographically challenging for responders to access. In addition, the psychological and psychosocial effects of witnessing and surviving catastrophic events may be substantial.
Indirect impacts on health because of disasters may include disruptions in modes of communication such as telephones, internet connections, and television services. Transportation may become limited due to damaged roads or highway infrastructure and vehicles. Community utilities, including electricity, water, and sewer systems, may be damaged or experience service disruptions.
Some communities are at greater risk during and following a disaster. Large populations, limited escape routes, population congestion, dense infrastructure, and low socioeconomic status increase community vulnerability (Donner & Rodriquez, 2011). Impoverished communities often have inadequate infrastructure to withstand a disaster and have disproportionately larger vulnerable populations.
A resilient community has the ability to recover from a disaster and can sustain itself in the face of hardship. Social connectedness is an essential characteristic of community resilience (Urban Footprint, 2023). Community members participate in their community, fostering a sense of togetherness and of feeling valued. Resilient communities also have social connections that provide emotional and physical support (Urban Footprint, 2023). Local organizations are trusted and provide needed community resources, such as food banks and financial assistance. Strong health care systems and government are prepared for disaster and recovery and have access to resources such as clean water and medical equipment. These communities continuously work on building resilience by improving social connections, ensuring government involvement in disaster management, improving risk communication to the entire community and vulnerable groups, improving community members’ physical and mental health, and increasing community social and economic health (Urban Footprint, 2023).
Impact of Disasters: Vulnerable Populations
Vulnerable populations are those with characteristics that affect their capacity to anticipate, respond to, and recover from the impact of disasters. The most vulnerable populations are low-income populations, older adults, and ethnic and racial minorities.
Those of low socioeconomic status are less prepared for disasters (SAMHSA, 2017). This population often lacks the resources to afford mitigation efforts, such as strengthening household structures and purchasing disaster insurance. Financial resources are most often used for immediate needs rather than to prepare for a potential disaster in the future. Even more vulnerable are people with lower incomes who are also experiencing homelessness , women, or residents of public housing because they often lack finances and resources needed in case of evacuation (SAMHSA, 2017). These groups are less likely to evacuate prior to a disaster. Following a disaster, low-income populations have greater difficulty obtaining aid, housing loans, food assistance, assistance with evacuation and transportation, and access to medical resources (Martin, 2019; SAMHSA, 2017). Consequences of disaster for low-income populations include greater incidence of homelessness, unemployment, injury, mortality, economic loss, depression, and posttraumatic stress (SAMHSA, 2017).
Older adults are more vulnerable to disasters as compared to other age groups (American Red Cross, 2020). Mortality rates within this population following disasters are greater because older adults are more likely to have chronic conditions, comorbidities , cognitive impairment, and medication needs. A greater number of older adults are dependent on assistive devices and caregiver support and are socially isolated.
Natural disasters disproportionately affect vulnerable populations, such as low-income or racial or ethnic minority groups. These groups are more likely to live in areas at high risk for natural disasters and in housing that poses safety risks when disasters occur. The Resilience in Survivors of Katrina (RISK) Project began as a research study in New Orleans, Louisiana, to examine the effects of economic and academic support on the retention of community college students. Over a 15-year period (2003–2018), researchers studied 1,019 parents who were low-income and primarily Black. In 2005, Hurricane Katrina disrupted the study, as many participants were hurricane victims. As a result, the study became the RISK Project, focusing on the effects and consequences of a disaster on vulnerable populations.
The results of the RISK Project have health policy implications for improving the quality of health for vulnerable populations and racial/ethnic minorities. The study found barriers to evacuation and care and a lack of long-term mental health services led to poorer health and psychosocial effects on individuals affected by disasters.
The recommendations for health policy included expanding avenues for primary prevention of disaster exposure.
- Protecting critical infrastructure and coastal wetlands to add a buffer to storm damage
- Revising building codes to require the elevation of new buildings and retrofitting existing buildings to provide flooding resilience
- Timely evacuation from at-risk areas and prohibiting employers from penalizing workers for early evacuation
- Providing public transportation for evacuation and affordable short-term housing for those who require evacuation and sustain damage to residences
- Improving post-disaster health care and mental health services, as physical and mental health are significantly affected by traumatic events
(See Raker et al., 2020.)
Assessment of Disaster or Public Health Emergency Risk
Beverly, the nurse described at the beginning of this chapter, conducted a community assessment to identify the needs of vulnerable populations within the community in the event of a hurricane. This assessment contributed to a larger assessment of the community disaster and public health emergency risk that assists the community in meeting the National Preparedness Goal , which outlines what entire communities need to prepare for different emergencies. The National Preparedness Goal is “a secure and resilient Nation with the capabilities required across the whole community to prevent, protect against, mitigate, respond to, and recover from the threats and hazards that pose the greatest risk” (Homeland Security, 2015). Community disaster and public health emergency risk assessment provides information for communities to plan for, protect, respond to, and recover from hazards.
Many frameworks are available to guide disaster risk assessment. For example, the Threat and Hazard Identification and Risk Assessment (THIRA), which should be completed every three years using a collaborative community approach (FEMA, 2023; FEMA/Homeland Security, 2018), guides communities to identify:
- The threats and hazards that could affect the community
- The impact of those hazards on the community
- The capabilities that the community should have to respond to those hazards
- The current capabilities of the community
- The gap between the target capabilities and current capabilities
Communities use multiple resources, such as previous experience, existing hazard assessments, organizational and business risk assessments, and new data, to identify potential natural, technological, and human-caused hazards (FEMA/Homeland Security, 2018). The process begins by determining the likelihood and impact of the hazard. The community then identifies the effect of the location, magnitude, and time of the hazard. Finally, the current capability of the community to handle the hazard and target or goal for capability is determined. The gap between the current and target goal for capability directs the community to plan to decrease the gap.
One method, the Asia-Pacific Climate Change Adaptation Information Platform (AP-PLAT), guides communities through six steps to identify potential community hazards, areas of increased exposure to hazard, and areas of increased vulnerability utilizing mapping (AP-PLAT, 2022). Table 32.1 provides details regarding the parts of the six-step disaster risk assessment process (AP-PLAT, 2022).
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Communities may use several tools, databases, and sources to complete disaster risk assessment. For example, the Federal Emergency Management Agency (FEMA) manages The National Risk Index , which is a tool that maps 18 natural hazards that impact the United States and identifies those most at risk. The Risk Index identifies potential natural hazards and ranks communities based on expected annual loss, social vulnerability, and community resilience. Communities are ranked according to risk. The higher the percentile, the greater the risk compared to other communities.
The National Risk Index ranks natural disaster risk by U.S. county and census track.
Use the interactive map to explore your community’s natural disaster risk, and then respond to the following questions.
- What is your community’s total risk index?
- How does your community’s expected annual loss, social vulnerability, and community resilience compare to other U.S. communities?
- What are natural hazard types in your area?
The Social Vulnerability Index (SVI) database is used to locate the most socially vulnerable populations within a community by census tract (Flanagan et al., 2018). SVI categories of vulnerability include socioeconomic status, household composition and disability, minority status and language, and housing and transportation. These vulnerability factors influence an individual’s and community’s capability to prepare for, respond to, and recover from disaster (Flanagan et al., 2018). This assists communities in identifying areas that may require additional assistance with disaster management.
The Social Vulnerability Index (SVI) ranks a community’s ability to respond to hazardous events across factors related to socioeconomic status, individual characteristics, housing type, transportation, and minority status.
Use the interactive map to explore your community’s SVI, and then respond to the following questions.
- What is your community’s most recent National Overall SVI Score? What does this mean?
- View the Prepared County Map – Overall Social Vulnerability. Within your community, where are the most vulnerable located?
- View the Prepared County Map – CDC/ATSDR SVI Themes. Which theme appears to affect your community most? Where are the most vulnerable, according to each theme, located? Other sources include existing hazard assessments and plans, historical data, homeland security data, private-sector assessments, and forecasting tools to determine future weather patterns, demographic shifts, or emerging threats (FEMA/Homeland Security, 2018).