Reference
Clear definitions for the terms used across this site. If we use a word you do not know, it is defined here.
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0–9
A pre-packed bag containing essential supplies for at least 72 hours, ready to grab during an evacuation. Commonly called a go-bag; New World Survival uses the term 72-hour bag. It typically includes water, food, medications, documents, a flashlight, a battery-powered radio, cash, and a change of clothes. Evacuation decisions happen fast, and having a bag ready eliminates the scramble to gather supplies under stress.
Related: Evacuation Order
The national emergency telephone number that connects callers to local police, fire, and EMS dispatch. The 911 system depends on telecommunications infrastructure — cell towers, telephone switches, and dispatch center equipment — all of which can fail during major disasters. During the 2021 Texas grid collapse, some 911 centers lost power and reverted to backup systems with reduced capacity.
Related: Emergency Alert System (EAS), Wireless Emergency Alert (WEA)
A
A structured review document produced after a disaster or emergency exercise that evaluates what happened, what worked, what failed, and what should change. AARs are the primary mechanism by which emergency management learns from events. They are the most reliable source for understanding disaster response decisions and outcomes.
Related: Incident Command System (ICS), Federal Emergency Management Agency (FEMA), Emergency Operations Center (EOC)
The power and confidence to act on your own decisions rather than waiting for instructions or rescue. Agency is the central outcome of all preparedness work: a person with a plan, supplies, skills, and practiced routines does not need to be told what to do when conditions change. Building agency is the reason NWS exists.
Related: Autonomy, Capability, Fortitude
A licensed radio communication system that operates independently of cell towers, internet, and commercial infrastructure. During disasters that knock out normal communications, ham radio operators provide emergency message relay, damage reports, and coordination support. Earning a Technician-class license requires passing a 35-question FCC exam — no Morse code required.
Related: American Radio Relay League (ARRL), Community Emergency Response Team (CERT), SKYWARN, Amateur Radio Emergency Service (ARES)
A volunteer program organized by the ARRL in which licensed amateur radio operators provide emergency communications during disasters. ARES groups coordinate with local emergency management agencies and activate when normal communications are disrupted. Membership requires only an amateur radio license and willingness to train.
Related: Amateur (Ham) Radio, American Radio Relay League (ARRL), Community Emergency Response Team (CERT)
An unfinished WPA Federal Writers' Project initiative (late 1930s–1941) that set out to document American food traditions region by region. Writers across the country produced essays on local foodways, community meals, ethnic food traditions, and seasonal customs before the project was abandoned when the U.S. entered World War II. Over 200,000 pages of manuscript survive and are a primary source for regional foodways research.
Related: Works Progress Administration (WPA), Federal Writers' Project
The national membership organization for amateur radio operators in the United States, founded in 1914. ARRL provides licensing exam resources, emergency communication training, and a nationwide network of local radio clubs. The ARRL section finder is the fastest way to locate a ham radio club in your area.
Related: Amateur (Ham) Radio, Amateur Radio Emergency Service (ARES), Community Emergency Response Team (CERT)
The nonprofit humanitarian organization that provides emergency shelter, food, and health services during and after disasters in the United States. Red Cross volunteers staff shelters, distribute supplies, and provide mental health support. The organization also offers first aid, CPR, and water safety training courses that are widely recognized as baseline certifications.
Related: Community Emergency Response Team (CERT), First Aid
The professional organization for civil engineers in the United States, which publishes the Infrastructure Report Card — a quadrennial assessment grading the condition of U.S. infrastructure across 17 categories. ASCE grades are widely cited in policy discussions and provide the most comprehensive public assessment of infrastructure condition. The most recent report card gave U.S. infrastructure an overall grade of C-minus.
Related: Design Basis, Building Code, Levee, Water Main
The fictional persona — Uncle Sam's wife — who hosted the USDA's 'Housekeepers' Chats' radio program from 1926 to 1946. Local actresses read USDA-supplied scripts featuring practical cooking advice, household tips, and economical recipes to millions of listeners. The compiled recipe books from the program are among the most widely distributed government publications of the 20th century.
Related: Bureau of Home Economics, Hazel Stiebeling
The ability to operate independently and make decisions without relying on external systems or approval. In preparedness, autonomy means a household can sustain itself when supply chains, utilities, or services are interrupted. Autonomy is not isolation; it is the capacity to function on your own terms when needed.
Related: Independence, Self-Sufficiency, Agency
B
A filter maintenance technique that reverses the direction of water flow through a filter element to clear trapped particles and restore flow rate. For hollow fiber membrane filters like the Sawyer Squeeze, backflushing uses clean water pushed through the output end of the filter to dislodge debris caught in the pores. Regular backflushing extends filter life and maintains filtration performance.
Related: Hollow Fiber Membrane, Micron
A volunteer who serves as the primary point of contact for emergency communication and coordination on a single block or small neighborhood area. Block captains maintain the communication tree, keep the neighborhood contact sheet current, and serve as the liaison to local emergency management during events. The role requires no formal training — just willingness to organize and a current contact list.
Related: Communication Tree, Map Your Neighborhood (MYN), Community Emergency Response Team (CERT)
A public health notice issued when a water system may have been contaminated — typically after a main break, treatment plant failure, or natural disaster. The advisory means tap water should be brought to a rolling boil for at least one minute before drinking, cooking, or brushing teeth. Boil advisories are issued by local water utilities or health departments and remain in effect until testing confirms the water is safe.
Related: Water Main
A rare but severe form of food poisoning caused by a toxin produced by the bacterium Clostridium botulinum, which thrives in low-oxygen, low-acid environments like improperly canned food. The toxin attacks the nervous system and can be fatal even in small amounts. Proper pressure canning temperatures and times are the primary defense against botulism in home-preserved food.
Related: Pressure Canner, National Center for Home Food Preservation (NCHFP)
A set of regulations governing the design, construction, and maintenance of buildings to ensure safety and structural integrity. Building codes are adopted and enforced at the state or local level, which means protection standards vary significantly by jurisdiction. Major disasters frequently lead to code revisions — the Camp Fire prompted California to adopt the most stringent WUI building codes in the country.
Related: Design Basis, Structural Assessment, Wildland-Urban Interface (WUI)
A division of the U.S. Department of Agriculture that operated from 1923 to 1962, producing practical, tested guidance on cooking, nutrition, household management, food preservation, and textile care for American families. The Bureau's Depression-era bulletins — written primarily by women scientists — are the foundational source material for the NWS Heritage content series. All Bureau publications are U.S. government works and fully in the public domain.
Related: Aunt Sammy, Hazel Stiebeling, Works Progress Administration (WPA), Federal Writers' Project
C
Having the skills, knowledge, tools, and resources to act effectively when needed. Capability is broader than equipment: a household with a generator but no knowledge of safe operation has equipment, not capability. NWS content is organized around building real capability across twelve self-reliance domains.
Related: Readiness, Resourcefulness, Fieldcraft
A colorless, odorless gas produced by burning fuel — gasoline, propane, natural gas, wood, charcoal — in enclosed or poorly ventilated spaces. Carbon monoxide poisoning is one of the leading causes of death after disasters, primarily from generators, grills, and camp stoves used indoors during power outages. Every household should have battery-operated CO detectors on every floor.
Related: Portable Generator
A sequence of failures in an interconnected system where the failure of one component triggers failures in others, often accelerating beyond the system's ability to recover. The 2003 Northeast blackout is a classic example — a software bug and untrimmed trees in Ohio initiated a chain of relay failures that blacked out 55 million people across eight states and Canada. Cascading failures are the primary way that infrastructure systems experience catastrophic events.
Related: Power Grid, Design Basis
The unbroken series of refrigerated storage and transportation steps that keeps perishable food at safe temperatures from production to consumption. A break in the cold chain — a power outage at a warehouse, a refrigerated truck breakdown, a grocery store losing power — can render large quantities of food unsafe. Most consumers interact with the cold chain only when their own refrigerator loses power.
Related: Just-in-Time Inventory
A structured system in which one person contacts two or three others, who each contact two or three more, rapidly spreading information through a network without requiring a single point of contact to reach everyone. Communication trees are the most reliable neighborhood-level alert system during events that disrupt cell and internet service. A well-maintained tree can reach 50 households in under 15 minutes using landlines or in-person contact.
Related: Social Capital, Block Captain, Map Your Neighborhood (MYN)
A FEMA-supported program that trains civilians in basic disaster response skills — fire safety, light search and rescue, first aid, and team organization. CERT volunteers serve as a bridge between professional responders and the community during disasters when emergency services are overwhelmed. Training is free and typically involves 20 hours of instruction through local emergency management agencies.
Related: Incident Command System (ICS), Emergency Operations Center (EOC)
Printed educational publications produced by state Cooperative Extension Services — typically at land-grant universities — covering agriculture, food preservation, gardening, home economics, and household management. Depression-era Extension bulletins from the 1930s are a primary source for NWS Heritage content, offering tested, practical guidance from a time when household self-reliance was an economic necessity, not a lifestyle choice.
Related: Cooperative Extension Service, Bureau of Home Economics
A nationwide network of offices — typically one per county — operated by land-grant universities in partnership with the USDA, providing research-based education in agriculture, food safety, home economics, and community development. Extension offices are where Master Gardener programs, food preservation workshops, and 4-H programs are administered. They are an underused civic resource for household self-reliance.
Related: Bureau of Home Economics, Master Gardener, National Center for Home Food Preservation (NCHFP)
A mixture of sodium chloride and sodium nitrite, dyed pink to prevent confusion with regular salt, used in meat curing and some sausage-making to inhibit the growth of Clostridium botulinum. Curing salt is measured precisely because both too little and too much carry risk: too little may not prevent botulism, and too much is toxic. It is not a substitute for cooking or proper refrigeration.
Related: Botulism
D
The temperature range between 40°F and 140°F in which foodborne bacteria multiply most rapidly. Perishable food left in the danger zone for more than two hours, or one hour above 90°F, should be discarded. The rule governs everything from outdoor cooking to power-outage food decisions.
Related: Food Storage
A fast-moving slurry of water, mud, rocks, and vegetation that flows downhill through channels, often triggered by heavy rain on steep slopes burned by wildfire. Debris flows are among the most lethal secondary hazards following wildfire because they move faster than a person can run and can strike with little warning. The 2018 Montecito debris flow in California — triggered by rain over the Thomas Fire burn scar — killed 23 people.
The buffer zone around a home where vegetation and other combustible materials are managed to slow or prevent the spread of wildfire. Defensible space is the single most effective action a homeowner in the WUI can take to protect their home. Most guidelines recommend three zones extending at least 100 feet from the structure.
Related: Wildland-Urban Interface (WUI), Wildfire, Fire-Adapted Community, Home Hardening
The set of conditions — the strongest wind, the highest flood, the coldest temperature — that an engineered system was built to withstand. When an event exceeds the design basis, the system may fail even if it was built and maintained correctly. Many infrastructure failures occur because the design basis was set decades ago using historical data that no longer reflects current risk.
Related: Cascading Failure, Levee, Building Code
A formal determination by the President that a disaster has occurred which exceeds state and local capacity to respond, triggering federal assistance. A disaster declaration unlocks FEMA Individual Assistance for households, Public Assistance for governments, and Hazard Mitigation grants. Not all emergencies receive declarations — the governor must request one and FEMA must assess the damage.
Related: Federal Emergency Management Agency (FEMA), FEMA Individual Assistance (IA), SBA Disaster Loan
Maintaining consistent habits and routines that support long-term preparedness and self-reliance. Discipline is the difference between owning a water filter and actually rotating your stored water on schedule. Most preparedness failures are not failures of equipment but failures of maintenance, practice, and follow-through.
Related: Vigilance, Prudence, Operational Readiness
The final stage of the power grid or water supply that delivers service from a local substation or treatment plant to individual homes and businesses. Distribution infrastructure — the poles, wires, pipes, and valves in your neighborhood — is typically the oldest and most vulnerable part of the system. Most power outages originate in the distribution network, not in generation or transmission.
Related: Power Grid, Water Main
A prolonged period of abnormally low precipitation that creates water shortages affecting agriculture, water supply, and fire risk. The U.S. Drought Monitor classifies drought severity from D0 (abnormally dry) to D4 (exceptional drought). Drought is both a hazard itself and a force multiplier for other hazards — it increases wildfire risk, strains water infrastructure, and can trigger agricultural economic crises.
Related: Wildfire
E
A sudden shaking of the ground caused by the release of energy along a geological fault. Earthquakes cannot be predicted with useful precision, making preparedness — structural retrofitting, securing heavy objects, and emergency kits — the primary defense. The San Andreas Fault in California and the New Madrid Seismic Zone in the central U.S. are the two most studied high-risk zones.
Related: Seismic Retrofit
The independent grid operator that manages the flow of electricity to roughly 90% of Texas. ERCOT is unique among U.S. grid operators because it is largely isolated from the two national interconnections, meaning Texas cannot easily import power from neighboring states during emergencies. This isolation was a central factor in the February 2021 grid collapse during Winter Storm Uri.
Related: Power Grid, Cascading Failure, Rolling Blackout
The national public warning system that broadcasts emergency alerts over radio, television, and cable systems. EAS replaced the older Emergency Broadcast System in 1997 and can be activated at the federal, state, or local level. EAS is the backbone of the national alert infrastructure, though most people now encounter emergency warnings through WEA on their phones.
Related: Wireless Emergency Alert (WEA), NOAA Weather Radio
The physical or virtual location where emergency management personnel coordinate information, resources, and decision-making during a disaster. Counties, cities, and states each maintain EOCs that activate during significant events. EOCs coordinate with FEMA's regional and national operations centers during federally declared disasters.
Related: Incident Command System (ICS), Federal Emergency Management Agency (FEMA), Community Emergency Response Team (CERT)
The rating system used to classify tornado intensity based on the damage they produce, ranging from EF-0 (minor damage, 65–85 mph winds) to EF-5 (total destruction, over 200 mph winds). The scale is applied after an event by survey teams who assess structural damage. Only about 1% of U.S. tornadoes reach EF-4 or EF-5 intensity.
An official directive from local authorities instructing residents to leave a defined area due to an imminent or ongoing threat. Evacuation orders may be mandatory or advisory, depending on jurisdiction and hazard. In most U.S. states, even mandatory evacuation orders cannot legally force residents to leave — but those who stay may not receive emergency assistance.
Related: Shelter in Place, 72-Hour Bag, Wireless Emergency Alert (WEA)
F
A documented plan that ensures every member of a household knows how to reach each other and where to meet if separated during an emergency. The plan should include an out-of-state contact (local lines may be jammed while long-distance calls go through), a meeting place near home, a meeting place outside the neighborhood, and each family member's route from school or work. Write it down — memory fails under stress.
Related: Communication Tree, 72-Hour Bag, Evacuation Order
The federal agency responsible for coordinating disaster response, recovery, and preparedness in the United States. FEMA administers Individual Assistance grants, the National Flood Insurance Program, and the public assistance program that reimburses state and local governments after declared disasters. FEMA operates within the Department of Homeland Security.
Related: Disaster Declaration, FEMA Individual Assistance (IA), National Flood Insurance Program (NFIP), SBA Disaster Loan
A WPA program (1935–1943) that employed writers to produce state guidebooks, oral histories, and cultural documentation across the country. The Project's life-history interviews — roughly 2,900 first-person accounts from farmers, factory workers, sharecroppers, and housewives — are a primary source for understanding how ordinary Americans lived, ate, and managed households during the Depression.
Related: Works Progress Administration (WPA), America Eats (WPA), Bureau of Home Economics
The FEMA program that provides financial assistance to individuals and households affected by a federally declared disaster. IA can cover temporary housing, home repairs, and other serious disaster-related needs not covered by insurance. The maximum IA grant changes annually; applicants must register within 60 days of the disaster declaration.
Related: Federal Emergency Management Agency (FEMA), Disaster Declaration, SBA Disaster Loan
Practical outdoor and hands-on skills that enable a person to operate effectively in non-ideal conditions. Fieldcraft includes fire-starting, basic navigation, shelter construction, water sourcing, knot-tying, and tool use. These skills are learned through practice, not reading, and they transfer across many preparedness scenarios.
Related: Capability, Resourcefulness, Discipline
An inventory rotation method in which the oldest items are used or consumed first, ensuring nothing expires while newer stock sits in front of it. FIFO is the foundational principle of food storage rotation — place new purchases behind existing stock so the older items get used first. The USDA Bureau of Home Economics taught this system in the 1930s, decades before the acronym existed.
Related: Pantry Discipline, Food Storage, Shelf Life
A conceptual model showing the three factors that determine how a wildfire behaves once ignited: fuel (type, moisture, arrangement), weather (wind, humidity, temperature), and topography (slope, aspect, elevation). Fire behavior is most dangerous when all three factors align — dry fuel, hot windy weather, and uphill terrain. The model is the foundation of wildfire prediction and firefighting strategy.
Related: Wildfire, Fuel Load, Red Flag Warning
A community in or near the WUI that has taken collective action to reduce its vulnerability to wildfire — including defensible space around homes, fire-resistant building materials, community fuel reduction projects, and practiced evacuation plans. The Firewise USA program, administered by the NFPA, provides a framework for achieving fire-adapted status. The concept shifts responsibility from firefighters alone to the entire community.
Related: Defensible Space, Wildland-Urban Interface (WUI), Wildfire, Building Code
A recognition program administered by the National Fire Protection Association that provides a framework for communities in or near the WUI to organize and take action to reduce wildfire risk. Participating communities complete an assessment, develop a plan, invest in annual mitigation projects, and host educational events. Over 2,000 communities in the U.S. currently hold Firewise USA recognition.
Related: Fire-Adapted Community, Defensible Space, Wildland-Urban Interface (WUI)
The immediate care given to a person who is injured or suddenly ill, before professional medical help arrives. Basic first aid skills — stopping bleeding, treating burns, performing CPR, recognizing stroke and heart attack — are among the most universally useful emergency skills a person can learn. Red Cross and American Heart Association courses provide standardized certification in 4–8 hours.
Related: Community Emergency Response Team (CERT), American Red Cross
A device installed inline on a rainwater collection downspout that captures and discards the initial flow of water from a rain event before cleaner water enters the storage barrel. The first flush from a roof carries concentrated bird droppings, atmospheric pollutants, and roofing material residue accumulated during dry periods. Discarding this fraction significantly improves the quality of collected rainwater.
An overflow of water onto land that is normally dry, caused by heavy rain, snowmelt, storm surge, or dam failure. Flooding is the most common and widespread natural hazard in the United States. Flash floods — rapid flooding within six hours of heavy rain — cause the majority of flood-related deaths.
Related: National Flood Insurance Program (NFIP), Floodplain, Storm Surge
The flat area adjacent to a river or coast that is naturally subject to periodic flooding. FEMA maps floodplains to determine insurance requirements and building restrictions. The commonly used term '100-year flood' means a flood that has a 1% chance of occurring in any given year — not that it happens only once per century.
Related: Flood, National Flood Insurance Program (NFIP)
The practice of maintaining a supply of shelf-stable food in the home for use during disruptions — power outages, supply chain interruptions, weather events, or income loss. A practical household food store starts with 72 hours of no-cook food and builds toward a 14-day rotating pantry of foods the household already eats. The key principle is rotation — stored food should be consumed and replaced regularly, not packed away and forgotten.
Related: FIFO (First In, First Out), Pantry Discipline
The practice of anticipating future needs, risks, and conditions before they arrive. Foresight is the foundation of all preparedness: storing water before the outage, reviewing insurance before the storm, building savings before the job loss. It is not prediction; it is the habit of asking what could change and preparing accordingly.
Related: Prudence, Situational Awareness, Readiness
Strength of character and resolve when facing adversity, discomfort, or prolonged difficulty. Fortitude is what sustains a household through a week-long power outage, a months-long recovery, or the steady work of building self-reliance over years. It is built through small, repeated choices to do the harder, more useful thing.
Related: Resilience, Stoicism, Discipline
The total amount of combustible material — dead leaves, fallen branches, standing dead trees, dense undergrowth — present in a given area of wildland. High fuel loads mean more material for a fire to consume, producing more intense heat and faster spread. A century of fire suppression in U.S. forests has allowed fuel loads to build far beyond historical levels in many ecosystems.
Related: Wildfire, Prescribed Burn, Fire Behavior Triangle
G
A mechanical device installed on a home's electrical panel that prevents a portable generator from back-feeding power into the utility grid — which can electrocute lineworkers. An interlock or transfer switch is required by the National Electrical Code for any generator connected to a home's wiring. Running a generator without one is both illegal and potentially fatal to utility workers restoring power.
Related: Power Grid, Portable Generator
A water filtration device that moves water through filter elements using gravity alone, requiring no electricity, pumps, or plumbing connection. Water poured into an upper chamber drips slowly through the filter media into a lower chamber ready to drink. Most household gravity filters use carbon block or ceramic elements and sit on a countertop.
Related: Reverse Osmosis, Hollow Fiber Membrane, NSF/ANSI Certification, PFAS (Per- and Polyfluoroalkyl Substances)
H
Strengthening a system, structure, or process against failure. A home can be hardened against storms with impact-resistant shutters; a financial position can be hardened with emergency savings; a communication plan can be hardened with backup channels. Hardening is preventive work done before conditions deteriorate.
Related: Resilience, Readiness, Operational Readiness
A USDA nutritionist who developed the four-tier dietary framework (liberal, moderate, minimum, restricted) that became the basis for federal food assistance policy. Her 1936 bulletin 'Diets to Fit the Family Income' demonstrated that a family could eat nutritiously at minimal cost — a framework that directly influenced what became the USDA Thrifty Food Plan, the basis for modern SNAP benefits.
Related: Bureau of Home Economics, Thrifty Food Plan, Supplemental Nutrition Assistance Program (SNAP)
A rigid, food-safe plastic identified by recycling symbol number 2, used in purpose-built water storage containers, food storage bins, and cutting boards. HDPE does not leach harmful chemicals into water under normal storage conditions and is rated for long-term food and water contact by the FDA. It is the standard material for emergency water storage containers.
Related: Potable
A prolonged period of abnormally high temperatures that poses health risks, strains power grids, and can be fatal — especially for elderly people, outdoor workers, and those without air conditioning. Heat is the deadliest weather hazard in the United States in most years, killing more people than hurricanes, tornadoes, and floods combined. The definition varies by region — 95°F in Seattle is more dangerous than 95°F in Phoenix because the population and infrastructure are not adapted to it.
Related: Power Grid, Rolling Blackout, Drought
A filtration technology using thousands of tiny tubes with microscopic pores that physically block bacteria, protozoa, and sediment while allowing water molecules to pass through. Hollow fiber filters are the core technology in portable filters like the Sawyer Squeeze and LifeStraw. They can be restored to near-original flow rate by backflushing water through the filter in reverse.
Related: Micron, Backflush, Gravity Filter
The process of modifying a home's exterior to resist ignition from wildfire embers, radiant heat, and direct flame contact. Key measures include replacing wood shake roofs with Class A rated materials, installing metal mesh over vents, using tempered or multi-pane windows, and removing combustible materials from within five feet of the structure. Research shows that home hardening and defensible space together are more effective than either alone.
Related: Defensible Space, Wildland-Urban Interface (WUI), Building Code, Fire-Adapted Community
A large rotating storm system that forms over warm ocean water, with sustained winds of 74 mph or higher. Hurricanes bring a combination of wind, storm surge, inland flooding, and tornadoes that can devastate coastlines and penetrate hundreds of miles inland. The Atlantic hurricane season runs from June 1 through November 30.
Related: Storm Surge, Saffir-Simpson Hurricane Wind Scale, Evacuation Order, National Oceanic and Atmospheric Administration (NOAA)
I
The standardized management structure used to organize emergency response in the United States. ICS provides a common framework — Incident Commander, Operations, Planning, Logistics, Finance — that allows multiple agencies to work together during any type of incident. Every FEMA-coordinated response and most local emergency responses use ICS.
Related: Emergency Operations Center (EOC), Community Emergency Response Team (CERT), Federal Emergency Management Agency (FEMA)
Freedom from dependence on systems, services, or other people for essential needs. Independence in preparedness is practical, not ideological. It means a household can provide its own water, power, heat, food, and communication for a meaningful period when normal supply is interrupted. Full independence is rare; meaningful independence is achievable.
Related: Autonomy, Self-Sufficiency, Resilience
A professional who inspects property damage after a disaster and determines how much the insurance company will pay on a claim. Adjusters may work for the insurance company (staff adjuster), for the policyholder (public adjuster), or independently. Policyholders have the right to hire a public adjuster to represent their interests, typically for 5–15% of the claim settlement.
Related: National Flood Insurance Program (NFIP)
J
A supply chain strategy in which goods are delivered to stores and warehouses only as they are needed, minimizing storage costs but reducing the buffer against disruption. Most U.S. grocery stores operate on a 3-day just-in-time cycle, meaning the store's shelves represent roughly three days of normal demand. Any disruption to transportation, distribution, or demand patterns can empty shelves within days.
Related: Cold Chain
L
The downslope movement of rock, soil, or debris driven by gravity, often triggered by heavy rainfall, earthquakes, or wildfire that destroys stabilizing vegetation. Post-wildfire landscapes are especially vulnerable to debris flows because the burned soil repels water instead of absorbing it. Landslides cause an average of 25–50 deaths per year in the U.S. and billions in property damage.
Related: Wildfire, Earthquake, Flood
An embankment — earthen or concrete — built along a waterway to contain floodwater and protect adjacent land. Levees are designed to a specific capacity; when a flood exceeds that design basis, the levee can be overtopped or may fail structurally. The U.S. has roughly 30,000 miles of levees, and the Army Corps of Engineers rates many as deficient.
Related: Floodplain, Flood, Design Basis
A bacterium that can grow even in refrigerated conditions, unlike most foodborne pathogens, making it a particular concern in soft cheeses, deli meats, and unpasteurized dairy. Listeriosis, the illness it causes, is especially dangerous for pregnant women, older adults, and people with weakened immune systems. Careful pasteurization and proper aging are the main defenses in home food preparation.
M
A community preparedness program that organizes neighbors into small groups (typically 15–20 households) to identify skills, resources, and vulnerabilities on their block before a disaster occurs. MYN was developed by the Washington State Emergency Management Division and has been adopted by communities across the country. The program takes about two hours to complete and produces a resource map, contact list, and simple action plan.
Related: Communication Tree, Social Capital, Block Captain, Community Emergency Response Team (CERT)
A trained volunteer who completes 40–100 hours of horticultural education through a state's Cooperative Extension Service and then provides gardening advice and community education in return. Master Gardener programs exist in all 50 states and are free or low-cost to participants. They are one of the most accessible civic on-ramps for learning food production skills.
Related: Cooperative Extension Service
A unit of measurement equal to one millionth of a meter, used to describe the pore size of water filters. A filter's micron rating indicates the smallest particle it will physically block: a 0.1-micron filter blocks bacteria and protozoa, while a 0.2-micron filter blocks protozoa but may allow some bacteria through. Viruses, at 0.02 to 0.3 microns, pass through most hollow fiber filters.
Related: Hollow Fiber Membrane, Gravity Filter, Reverse Osmosis
The process of identifying, containing, and removing mold growth from a building after water damage. Mold can begin growing within 24–48 hours of water intrusion and poses respiratory health risks, especially for children, elderly people, and those with asthma. Professional remediation is recommended when mold covers more than 10 square feet or is found inside wall cavities or HVAC systems.
Related: Structural Assessment
A practice of reciprocal support in which community members voluntarily share resources, skills, and labor based on need rather than charity. Mutual aid networks are peer-to-peer — participants both give and receive — distinguishing them from top-down charitable organizations. Historical examples include Depression-era cooperative buying clubs, community canning centers, and church dinner rotations.
Related: Social Capital, Communication Tree
N
The USDA-funded research center at the University of Georgia that develops and maintains the current science-based guidelines for safe home food preservation. NCHFP recommendations are the definitive authority on canning times, pressures, and methods in the United States. Any historical preservation recipe should be cross-checked against NCHFP guidelines before use.
Related: Pressure Canner, Water-Bath Canning
The federal program that provides flood insurance to property owners, renters, and businesses in participating communities. Standard homeowner's insurance does not cover flood damage — NFIP policies are typically the only source of flood coverage for most households. NFIP policies have a 30-day waiting period before coverage takes effect.
Related: Flood, Floodplain, Federal Emergency Management Agency (FEMA)
The federal science agency responsible for monitoring oceans, atmosphere, and climate, and for providing weather and climate data. NOAA is the parent agency of the National Weather Service, the National Hurricane Center, and the Storm Prediction Center. NOAA satellites provide the imagery and data that power most weather forecasting in the United States.
Related: National Weather Service (NWS), NOAA Weather Radio
The federal agency within NOAA responsible for weather forecasting, severe weather warnings, and climate monitoring in the United States. The NWS operates 122 local forecast offices that issue watches, warnings, and advisories for their respective regions. NWS forecasters are the source of tornado warnings, hurricane forecasts, flood watches, Red Flag Warnings, and winter storm alerts.
Related: National Oceanic and Atmospheric Administration (NOAA), NOAA Weather Radio, Red Flag Warning, SKYWARN
A nationwide network of radio stations that broadcast continuous weather information directly from National Weather Service offices. Weather radios can be programmed to sound an alarm for specific hazards in your county — severe thunderstorms, tornadoes, flash floods, and other warnings. It is the only alert system that works without internet or cell service.
Related: Wireless Emergency Alert (WEA), Red Flag Warning, National Weather Service (NWS)
An independent product certification issued by NSF International verifying that a water treatment device meets specific performance standards. Each standard number covers different contaminants: NSF 42 covers taste and odor, NSF 53 covers health contaminants including PFAS when specifically listed, and NSF 58 covers reverse osmosis systems. A product certified to one standard is not automatically certified to others.
Related: PFAS (Per- and Polyfluoroalkyl Substances), Gravity Filter, Reverse Osmosis
O
Being fully capable of acting immediately when conditions require it. Operational readiness means supplies are accessible, equipment is tested and maintained, plans are current, and household members know their roles. It is the difference between having a plan and being ready to execute it right now.
Related: Readiness, Discipline, Capability
P
The systematic practice of maintaining, rotating, and inventorying a household food supply so that nothing expires unused and staples are always available. Pantry discipline includes FIFO rotation, regular inventory checks, purchasing based on what's actually used (not aspirational), and seasonal restocking. The USDA Bureau of Home Economics taught these systems in the 1930s as basic household economics.
Related: FIFO (First In, First Out), Food Storage, Shelf Life
A serious, sometimes fatal illness caused by eating shellfish that have accumulated toxins produced by certain algae blooms, commonly called red tide. PSP toxins are not destroyed by cooking, which is why shellfish harvesting depends on checking official closure status before every outing rather than on any preparation method. Symptoms can begin within minutes and progress to respiratory paralysis in severe cases.
Related: Danger Zone (Food Safety)
A group of more than 12,000 synthetic chemical compounds used in industrial processes and consumer products since the 1940s. PFAS do not break down naturally in the environment or the human body, earning the name 'forever chemicals.' Exposure through drinking water has been linked to thyroid disruption, immune system effects, and elevated risk of certain cancers.
Related: NSF/ANSI Certification, Reverse Osmosis, Gravity Filter
A measurement of acidity or alkalinity on a scale of 0 to 14, with lower numbers indicating higher acidity. In home food preservation, pH determines which canning method is safe: foods at pH 4.6 or below can be safely water-bath canned, while foods above that threshold require pressure canning to destroy botulism spores. Testing pH matters most when a recipe adds acid to a naturally low-acid food.
Related: Water-Bath Canning, Pressure Canner, Botulism
A fuel-powered engine that produces electricity for temporary use during a power outage. Portable generators can power essential appliances — refrigerators, medical devices, lights, phone chargers — but must be operated outdoors due to carbon monoxide risk. Carbon monoxide from generators kills more people after hurricanes than the storms themselves in many events.
Related: Generator Interlock, Power Grid, Carbon Monoxide (CO)
The practice of confirming a wild plant, mushroom, or other foraged food matches a single edible species with total certainty, using multiple physical characteristics rather than a partial resemblance. Positive identification is the foundational discipline of foraging, because look-alike species can be mildly unpleasant or fatally toxic. The rule among experienced foragers is simple: never eat on a maybe.
Safe for human consumption — meaning the water has been treated, tested, or verified to be free of harmful biological and chemical contaminants at levels exceeding health standards. Tap water from a public water system is potable; untreated surface water from a stream or rain barrel is not.
Related: Boil Water Advisory, Gravity Filter, Reverse Osmosis
Water that is safe to drink, cook with, and use for personal hygiene without risk of illness. Municipal tap water in the U.S. is treated to potable standards, but that treatment depends on functioning infrastructure — power to run treatment plants, intact distribution pipes, and chemical supply chains. When any of those fail, tap water may no longer be potable, and a boil water advisory or do-not-use order is issued.
Related: Boil Water Advisory, Water Storage
The interconnected network of generation plants, transmission lines, and distribution systems that delivers electricity from producers to consumers. The U.S. grid operates as three major interconnections — Eastern, Western, and ERCOT (Texas) — that function largely independently. The grid is the single most complex machine in the country, with roughly 160,000 miles of high-voltage transmission lines.
Related: Cascading Failure, Electric Reliability Council of Texas (ERCOT), Rolling Blackout, Generator Interlock
A planned, intentionally set fire used to manage vegetation, reduce fuel loads, and restore fire-dependent ecosystems. Prescribed burns are conducted under specific weather conditions by trained crews with containment resources in place. Decades of fire suppression have created a prescribed burn deficit — the backlog of land that needs burning far exceeds current capacity.
Related: Wildfire, Defensible Space, Fuel Load
A specialized piece of kitchen equipment that processes food in sealed jars at temperatures above 240°F — the temperature required to destroy Clostridium botulinum spores in low-acid foods like vegetables, meat, and poultry. A pressure canner is not the same as a pressure cooker; canners are larger, have a pressure gauge or weighted regulator, and are tested to specific standards. Pressure canning is the only safe method for home preservation of low-acid foods.
Related: National Center for Home Food Preservation (NCHFP), Water-Bath Canning
Making careful, forward-thinking decisions that account for future consequences. Prudent preparedness means building capability steadily rather than panic-buying, choosing reliable equipment over the cheapest option, and maintaining what you have before acquiring more.
Related: Foresight, Discipline, Sustainability
R
A container that captures and stores rainwater from a roof's gutter system for later use in irrigation, cleaning, or emergency water supply. Rain barrels are legal in most U.S. states, though some states regulate the volume that can be collected. A single barrel typically holds 50–80 gallons; the water is not potable without treatment.
Related: Water Storage
The state of being equipped, informed, and mentally prepared to respond to challenges or emergencies. In a preparedness context, readiness means having plans, supplies, skills, and the calm confidence to act when conditions change.
Related: Resilience, Operational Readiness, Capability
A forecast alert issued by the National Weather Service when weather conditions are especially favorable for wildfire ignition and rapid spread — typically a combination of low humidity, high temperatures, and strong winds. Red Flag Warnings trigger increased staffing at fire stations and pre-positioning of suppression resources. They do not mean a fire has started — they mean conditions are dangerous if one does.
Related: Wildfire, National Weather Service (NWS), NOAA Weather Radio
The capacity to withstand disruption and recover from hardship without permanent loss of function. Resilience applies at every scale, from a single household maintaining normalcy during a power outage to a community rebuilding after a flood. Physical preparedness, financial reserves, social networks, and mental fitness all contribute to resilience.
Related: Readiness, Fortitude, Sustainability
The ability to solve problems with whatever is available rather than waiting for ideal conditions or supplies. Resourcefulness is a skill that improves with practice. Heritage-era households, working with far fewer commercial products, developed resourcefulness as a core survival trait.
Related: Capability, Fieldcraft, Resilience
A water filtration method that forces water under pressure through a semi-permeable membrane with pores small enough to block dissolved contaminants, including PFAS, arsenic, nitrates, fluoride, and lead. Reverse osmosis systems are certified to NSF/ANSI 58 and remove a broader range of chemical contaminants than carbon or gravity filters. They require electricity and produce waste water alongside purified water.
Related: PFAS (Per- and Polyfluoroalkyl Substances), NSF/ANSI Certification, Gravity Filter, Micron
An intentional, temporary shutdown of electricity to rotating sections of the grid to prevent a total system collapse when demand exceeds supply. Rolling blackouts typically last 15–60 minutes per area before power is restored and the blackout moves to the next zone. They are a last-resort measure that signals the grid is at or beyond its limits.
Related: Power Grid, Electric Reliability Council of Texas (ERCOT), Cascading Failure
S
The 1–5 rating system used to classify hurricane intensity based on sustained wind speed, from Category 1 (74–95 mph, minimal damage) to Category 5 (157+ mph, catastrophic damage). The scale measures only wind — it does not account for storm surge, rainfall, or flooding, which often cause more damage and deaths than wind alone. A Category 1 hurricane with heavy rain can cause more flooding damage than a Category 4 with less rain.
Related: Hurricane, Storm Surge
A low-interest loan from the U.S. Small Business Administration available to homeowners, renters, businesses, and nonprofits after a declared disaster. Despite the name, SBA disaster loans are available to individuals, not just businesses — they cover property damage, personal property replacement, and economic injury. Loan amounts can reach $500,000 for real estate and $100,000 for personal property.
Related: Federal Emergency Management Agency (FEMA), Disaster Declaration, FEMA Individual Assistance (IA)
The modification of an existing building to make it more resistant to earthquake damage — typically by bolting the structure to its foundation, bracing cripple walls, and reinforcing connections between floors and walls. In earthquake-prone regions, seismic retrofits are among the most cost-effective preparedness investments a homeowner can make. Some jurisdictions offer incentive programs that cover a portion of retrofit costs.
Related: Earthquake, Building Code, Structural Assessment
The ability to meet your own essential needs without relying on outside support. Self-sufficiency exists on a spectrum, from maintaining a three-day water supply to growing a significant portion of your own food. Most households benefit from building toward greater self-sufficiency incrementally rather than attempting full independence overnight.
Related: Autonomy, Independence, Sustainability
The length of time a food product remains safe and nutritionally adequate when stored under recommended conditions. 'Best by' and 'use by' dates on most shelf-stable foods are quality indicators, not safety cutoffs — many products remain safe well past those dates. The exception is infant formula, which has a federally regulated use-by date tied to nutrient degradation.
Related: FIFO (First In, First Out), Food Storage, Pantry Discipline
An emergency instruction to remain inside your current building and seal it against an external hazard — typically a chemical release, severe weather, or active threat. Sheltering in place is distinct from evacuation; it means staying put, closing windows and doors, and in chemical events, sealing gaps with plastic and tape. The decision to shelter vs. evacuate depends on the specific hazard.
Related: Evacuation Order, 72-Hour Bag, NOAA Weather Radio
Understanding your environment, recognizing what is normal, and noticing when conditions change. In preparedness, situational awareness means knowing the hazards in your region, understanding the systems your household depends on, and maintaining enough attention to recognize when something shifts. It is a trainable skill, not an innate trait.
Related: Vigilance, Foresight, Operational Readiness
A National Weather Service program that trains volunteer weather spotters to identify and report severe weather conditions — tornadoes, large hail, damaging winds, and flash flooding — to their local NWS forecast office. SKYWARN training is free, typically 2–3 hours, and available through local NWS offices. Spotter reports are a critical data source for NWS forecasters issuing warnings.
Related: National Weather Service (NWS), NOAA Weather Radio, Community Emergency Response Team (CERT)
A device that converts sunlight into electricity using photovoltaic cells. For household preparedness, solar panels paired with battery storage provide backup power that does not depend on fuel or the grid. A basic portable solar setup (200W panel + battery station) can keep phones charged, run LED lights, and power a small refrigerator during a multi-day outage.
Related: Generator Interlock, Power Grid
A philosophical tradition emphasizing emotional self-regulation, focus on what you can control, and endurance through difficulty. In a preparedness context, stoic principles apply directly: control your response rather than the situation, prepare for what is likely rather than fear what is possible, and maintain composure so those around you can function.
Related: Fortitude, Discipline, Agency
An abnormal rise in sea level generated by a storm's winds pushing ocean water onshore. Storm surge is the deadliest hazard associated with hurricanes, responsible for more fatalities than wind in most major events. Surge heights can exceed 20 feet in extreme storms.
Related: Hurricane, Evacuation Order, Flood
A professional evaluation of a building's structural integrity after a disaster — determining whether the structure is safe to enter, safe to occupy, or requires demolition. Structural assessments should be performed by a licensed structural engineer, not a general contractor. A typical post-disaster residential assessment costs $300–$600.
Related: Mold Remediation, Building Code
The federal agency within HHS that leads public behavioral health efforts, including disaster mental health response. SAMHSA operates the Disaster Distress Helpline (1-800-985-5990) — a 24/7 crisis counseling service for people experiencing emotional distress related to any natural or human-caused disaster. The helpline is free, multilingual, and confidential.
A severe thunderstorm characterized by a deep, persistent rotating updraft called a mesocyclone. Supercells are the most dangerous type of thunderstorm and are responsible for nearly all significant tornadoes, as well as very large hail, damaging winds, and flash flooding. They can persist for hours and travel hundreds of miles.
Related: Tornado, Enhanced Fujita (EF) Scale
The federal program that provides nutrition assistance to low-income individuals and families through an electronic benefits transfer (EBT) card usable at authorized retailers. SNAP benefits are calculated based on the USDA Thrifty Food Plan — the minimum-cost nutritionally adequate diet. After a presidential disaster declaration, D-SNAP (Disaster SNAP) can provide temporary food benefits to disaster-affected households that don't normally qualify.
Related: Thrifty Food Plan, Hazel Stiebeling, Federal Emergency Management Agency (FEMA)
Maintaining long-term viability with limited or finite resources. In preparedness, sustainability means building systems that can function over weeks and months, not just the first 72 hours. A garden that produces food year after year is more sustainable than a stockpile that depletes. Sustainable preparedness plans account for resupply, rotation, and maintenance.
Related: Self-Sufficiency, Resilience, Prudence
T
A measure of the combined concentration of all inorganic and organic substances dissolved in water, expressed in milligrams per liter or parts per million. TDS includes minerals like calcium and magnesium (which are harmless or beneficial), as well as contaminants like nitrates and heavy metals. A high TDS reading does not indicate unsafe water; a low reading does not confirm safety.
Related: Reverse Osmosis, Turbidity
The USDA's estimate of the minimum cost of a nutritionally adequate diet, used as the basis for calculating SNAP (food stamp) benefits. The Thrifty Food Plan is a direct descendant of Hazel Stiebeling's 1936 four-tier dietary framework. It is updated periodically — the most recent revision in 2021 increased the estimated cost by roughly 20%.
Related: Hazel Stiebeling, Supplemental Nutrition Assistance Program (SNAP), Bureau of Home Economics
A violently rotating column of air extending from a thunderstorm to the ground. Tornadoes can produce winds exceeding 300 mph and destroy well-built structures in seconds. The U.S. experiences roughly 1,200 tornadoes per year, more than any other country.
Related: Supercell, Enhanced Fujita (EF) Scale
A series of ocean waves generated by a large-scale disturbance — usually an undersea earthquake, volcanic eruption, or submarine landslide. Tsunami waves can travel across entire ocean basins at jet speed and arrive at coastlines with devastating force. The Pacific Northwest and Alaska are the U.S. regions with the highest tsunami risk, though the Atlantic and Gulf coasts have historical exposure.
Related: Earthquake, Evacuation Order
A measure of water cloudiness caused by suspended particles — sediment, algae, or other matter that scatters light passing through the water. High turbidity can interfere with chemical disinfection by shielding pathogens from UV light or chlorine contact. Turbid water should be pre-filtered or allowed to settle before chemical treatment.
Related: Potable, Hollow Fiber Membrane, Backflush
U
The federal science agency responsible for studying the nation's landscape, natural resources, and natural hazards — including earthquakes, volcanoes, landslides, and wildfire. USGS operates the earthquake monitoring network, produces wildfire risk maps, and maintains stream gauges that feed flood forecasting models. USGS data is the foundation of most natural hazard risk assessments in the United States.
Related: Earthquake, Wildfire, National Oceanic and Atmospheric Administration (NOAA)
V
Sustained, calm attention to conditions that could affect household safety or stability. Vigilance is not anxiety. It is the practiced habit of monitoring weather alerts, checking supplies on a schedule, maintaining equipment, and staying informed through reliable sources without letting the monitoring itself become a source of stress.
Related: Situational Awareness, Foresight, Discipline
The process of identifying which households on a block have members who may need additional help during an emergency — people who live alone, have mobility limitations, depend on medical equipment, have young children, or don't speak English. Vulnerability maps are sensitive documents that should be maintained on paper by 2–3 trusted block coordinators and updated annually. The goal is to ensure no one is forgotten during an evacuation or outage.
Related: Block Captain, Map Your Neighborhood (MYN), Communication Tree
W
A large underground pipe that carries treated drinking water from a distribution hub to neighborhoods and buildings. Water mains in the U.S. range in age from new installations to cast-iron pipes over 100 years old. The American Society of Civil Engineers estimates there are approximately 240,000 water main breaks per year in the U.S., resulting in the loss of roughly 6 billion gallons of treated water daily.
Related: Distribution System, Boil Water Advisory
A commercial sodium hypochlorite additive formulated to maintain a protective chlorine residual in stored water for up to five years when added at the manufacturer's specified dose at fill time. It addresses the natural dissipation of chlorine residual that occurs in tap water stored in sealed containers over months. One package typically treats up to 55 gallons and costs $10 to $15.
Related: Potable, HDPE (High-Density Polyethylene)
The practice of maintaining a supply of clean drinking water for use during disruptions to the municipal water system. The standard recommendation is one gallon per person per day for at least three days — covering drinking, cooking, and basic hygiene. Stored water should be replaced every six months if using tap water, or stored in commercially sealed containers with longer shelf lives.
Related: Boil Water Advisory
A home preservation method in which sealed jars of high-acid food — fruits, pickles, jams, tomatoes with added acid — are processed in boiling water (212°F) for a specified time. Water-bath canning is safe only for high-acid foods (pH 4.6 or below); low-acid foods require pressure canning. The method has been used in American households since the 19th century and is documented extensively in USDA bulletins.
Related: Pressure Canner, National Center for Home Food Preservation (NCHFP)
An unplanned fire burning in natural vegetation — forests, grasslands, or brush. Wildfires can be ignited by lightning or human activity and may spread across thousands of acres when conditions align. The U.S. averages roughly 70,000 wildfires per year.
Related: Wildland-Urban Interface (WUI), Defensible Space, Prescribed Burn, Fire Behavior Triangle
The zone where developed land — houses, businesses, infrastructure — meets or intermingles with undeveloped wildland vegetation. Homes in the WUI face elevated wildfire risk because fire can move directly from wildland fuels to residential structures. As of 2020, the WUI contains roughly 44 million U.S. homes — 32% of all housing.
Related: Defensible Space, Wildfire, Fire-Adapted Community
A weather event bringing heavy snow, ice, freezing rain, or extreme cold over a wide area. Winter storms can collapse power grids, make roads impassable, and isolate households for days. Ice storms are particularly damaging to power infrastructure because ice accumulation on lines and trees causes widespread outages.
Related: Generator Interlock, Rolling Blackout
A public safety system that pushes short emergency alerts directly to cell phones in a targeted geographic area without requiring a subscription or app. WEA messages include AMBER alerts, severe weather warnings, and presidential alerts. WEA depends on cell tower coverage — if towers are down or the area lacks coverage, the alert will not reach phones in that zone.
Related: NOAA Weather Radio, Evacuation Order, Emergency Alert System (EAS)
A New Deal agency (1935–1943) that employed millions of Americans on public works projects during the Great Depression, including construction, arts, and writing. The WPA's Federal Writers' Project produced the 'America Eats' manuscripts documenting regional foodways and roughly 2,900 life-history interviews with ordinary Americans — both now invaluable primary sources for understanding Depression-era household economics.
Related: Federal Writers' Project, Bureau of Home Economics, America Eats (WPA)
This glossary is updated as the site grows. Last updated: 2026-07-16. 139 terms defined.
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Social Capital
The networks of relationships among people in a community that enable cooperation, trust, and collective action. In disaster research, social capital is the single strongest predictor of both survival and recovery — stronger than income, infrastructure quality, or government response speed. Neighborhoods where residents know each other by name evacuate faster, share resources more effectively, and rebuild more completely.
Related: Mutual Aid, Communication Tree, Block Captain