32.1 Types of Disasters

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.

Figure 32.2 On March 11, 2011, a magnitude 9.1 earthquake occurred off the eastern coast of Japan, near the Tōhoku region. The quake was the fourth largest in recorded history and set off a massive tsunami, with some waves estimated to be as much as 133 feet high. The tsunami in turn caused the Fukushima Daiichi nuclear disaster, which involved the meltdown of three of the power plant’s reactors, the release of radioactive water, and the evacuation of hundreds of thousands of residents in what became the exclusion zone. This photo of the tsunami-damaged interior of a seaside recreation facility within the exclusion zone was taken 10 years later. The scope of the disaster complicated emergency response operations and meant that staff, volunteers, and resources were overburdened and had difficulty keeping up with mounting needs. Lack of detailed planning for vulnerable populations, such as older adult and hospitalized clients, resulted in deaths that may have been avoidable. (Committee on Lessons Learned from the Fukushima Nuclear Accident for Improving Safety and Security of U.S. Nuclear Plants, 2014) (credit: “Marine House Futaba” by Joi Ito/Flickr, CC BY 2.0)

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:

1. 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.
2. Social disasters: Examples include warfare, genocide, civil unrest, and terrorism.
3. 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).

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).

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).

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).

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 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.