Disaster Management: Comprehensive Notes
Definitions and Overview
A “disaster” can be defined as "any occurrence that causes damage, ecological disruption, loss of human life or deterioration of health and health services on a scale sufficient to warrant an extraordinary response from outside the affected community or area" (1). A “hazard” can be defined as any phenomenon that has the potential to cause disruption or damage to people and their environment (2). Emergencies and disasters do not only affect health and well-being of people; frequently, large numbers of people are displaced, killed or injured, or subjected to greater risk of epidemics. Considerable economic harm is also common. Disasters cause great harm to the existing infrastructure and threaten the future of sustainable development. Disasters are not confined to a particular part of the world; they can occur anywhere and at any time. Major emergencies and disasters have occurred throughout history and, as the world's population grows and resources become more limited, communities are increasingly vulnerable to the hazards that cause disaster. Statistics gathered since 1969 show a rise in the number of people affected by disasters. Since there is little evidence that the actual events causing disasters are increasing in either intensity or frequency, it can only be concluded that vulnerability to disaster is growing. For each disaster listed in officially recognized disaster databases, there are some other smaller emergencies with destructive impact on local communities that are unacknowledged.
There are many types of disasters such as earthquakes, cyclones, floods, tidal waves, landslides, volcanic eruptions, tornadoes, fires, hurricanes, snow storms, severe air pollution (smog), heat waves, famines, epidemics, building collapse, toxicologic accidents (e.g., release of hazardous substances), nuclear accidents and warfare etc. Warfare is a special category, because damage is the intended goal of action. Every catastrophic event has its own special features. Some can be predicted several hours or days beforehand, as in the case of cyclones or floods; others such as earthquakes occur without warning.
The relative number of injuries and deaths differ, depending on factors such as the type of disaster, the density and distribution of the population, environmental condition, level of preparedness, and the opportunity of warning. Injuries usually exceed deaths in explosions, earthquakes, typhoons, hurricanes, fires, tornadoes etc. Death frequently exceeds injuries in landslides, avalanches, volcanic eruptions, tidal waves, floods etc. (3).
Types of Disasters and Predictability
The types of emergency vary according to the kind of disaster, and how and when it strikes. In earthquakes, there is a high level of mortality, as a result of people being crushed by falling objects. The risk is greater inside or near dwellings but very small in the open. Consequently, earthquakes at night are more deadly. During the night fractures of pelvis, thorax and spine are common, because earthquakes strike while people are lying in bed. In volcanic eruptions, mortality is high in the case of mudslides (e.g., deaths in Colombia in 1985) and glowing clouds (e.g., deaths at Saint-Pierre in Martinique). There may be injuries, burns and suffocation. In floods, mortality is high mainly in cases of sudden flooding, e.g., flash floods, collapse of dams or tidal waves. Fractures, injuries and bruises may occur. If the weather is cold, cases of accidental hypothermia may occur. In cyclones and hurricanes, mortality is not high unless tidal waves occur. The combined effect of wind and rain may cause houses to collapse. A large number of objects may be lifted in the air and carried along by the wind, giving rise to injuries. In droughts, mortality may increase in areas where drought leads to famines, with protein-calorie malnutrition and vitamin deficiencies (particularly vitamin A), leading to xerophthalmia and blindness. In famine conditions measles, respiratory infections and diarrhoea with dehydration may cause a massive increase in infant mortality. When people migrate and settle on the outskirts of famine-hit areas, poor hygiene and overcrowding may facilitate spread of endemic diseases such as tuberculosis, parasitic diseases and malaria (4).
Short-Term Health Effects and the Disaster Cycle
On the whole, morbidity resulting from a disaster can be classified into four types:
a. Injuries;
b. Emotional stress;
c. Epidemic of disease;
d. Increase in indigenous diseases.
The short-term effects of major disasters are summarized in Table 1. There are three fundamental aspects of disaster management:
a. disaster response;
b. disaster preparedness;
c. disaster mitigation.
These three aspects correspond to different phases in the so-called “disaster cycle” as shown in Fig. 1.
Disaster Impact and Medical Management
Medical treatment for a large number of casualties is likely to be needed only after certain types of disaster. Most injuries are sustained during the impact, and thus the greatest need for emergency care occurs in the first few hours. The management of mass casualties can be divided into search and rescue, first aid, triage and stabilization of victims, hospital treatment and redistribution of patients to other hospitals if necessary.
Search, Rescue and First Aid
After a major disaster, the need for search, rescue and first aid is so great that organized relief services will meet only a small fraction of the demand. Most immediate help comes from uninjured survivors.
Field Care
Most injured persons converge spontaneously to health facilities, using whatever transport is available, regardless of facility status. Resources must be redirected to this new priority. Bed availability and surgical services should be maximized. Provisions should be made for food and shelter. A central contact point should respond to inquiries from patients’ relatives and friends. Priority should be given to victim identification and adequate mortuary space should be provided.
Triage
When the quantity and severity of injuries overwhelm the capacity of health facilities, triage is used. The principle of “first come, first treated” is not followed in mass emergencies. Triage rapidly classifies the injured by injury severity and the likelihood of survival with prompt care. It must be adapted to locally available skills. Higher priority is given to victims whose immediate or long-term prognosis can be dramatically improved with simple intensive care. Moribund patients with questionable benefit have the lowest priority. Triage is the only approach to maximize benefits for the greatest number of injured in a major disaster.
Although different triage systems exist, the most common uses a four-color code:
Red: high priority treatment or transfer,
Yellow: medium priority,
Green: ambulatory patients,
Black: dead or moribund.
Triage should be carried out at the disaster site to determine transport priority and admission to hospital or treatment centers where care priorities will be reassessed. Ideally, local health workers should be taught triage principles as part of disaster training.
Persons with minor or moderate injuries should be treated at their own homes to avoid social dislocation and further drain on central facilities. Seriously injured should be transported to hospitals with specialized treatment facilities.
Tagging
All patients should be identified with tags stating their name, age, place of origin, triage category, diagnosis, and initial treatment.
Identification of Dead
Care of the dead is essential. A large number of dead can impede rescue activities. Care of the dead includes: (1) removal from the disaster scene; (2) shifting to the mortuary; (3) identification; (4) reception of bereaved relatives. Proper respect for the dead is important. Health hazards from cadavers are minimal if death results from trauma, and corpses are unlikely to cause disease outbreaks such as typhoid, cholera or plague. If bodies contaminate streams, wells, or water sources (as in floods), they may transmit gastroenteritis or food poisoning. Dead bodies also represent a social problem.
Relief Phase and Humanitarian Aid
Relief phase begins when external assistance reaches the disaster area. The type and quantity of humanitarian relief supplies are determined by (1) the type of disaster and (2) the type and quantity of supplies available locally. Immediately after a disaster, the most critical health supplies are those needed for treating casualties and preventing the spread of communicable diseases. After the initial emergency phase, needed supplies include food, blankets, clothing, shelter, sanitary engineering equipment and construction material. A rapid damage assessment identifies needs and resources. Disaster managers must be prepared to receive large quantities of donations. Four principal components in managing humanitarian supplies are:
(a) acquisition of supplies;
(b) transportation;
(c) storage;
(d) distribution.
Epidemiologic Surveillance and Disease Control
Disasters can increase the transmission of communicable diseases through several mechanisms:
Overcrowding and poor sanitation in temporary settlements.
Population displacement may introduce diseases to susceptible populations.
Disruption and contamination of water supply, sewerage, and power systems.
Disruption of routine control programs as funds and personnel are diverted to relief work.
Ecological changes may favor breeding of vectors.
Displacement of domestic and wild animals can carry zoonoses (e.g., leptospirosis, rabbies, etc.).
Emergency food, water and shelter from new sources may itself be a disease source.
Outbreaks of gastroenteritis are the most commonly reported post-disaster disease; acute respiratory infections rise in displaced populations. Vector-borne diseases may take weeks to reach epidemic levels. Veterinary services may be needed to evaluate risks from animals. Dogs, cats and other domestic animals near shelters can be reservoirs for leptospirosis, rickettsiosis, etc. Wild animals can carry infections such as equine encephalitis, rabies, etc. The principles for preventing and controlling communicable diseases after a disaster are: (a) implement public health measures quickly to reduce transmission; (b) organize reliable disease reporting systems to identify outbreaks and promptly initiate control; (c) investigate all disease outbreaks rapidly (5).
Vaccination (5)
Health authorities often face pressure to begin mass vaccination programs (typhoid, cholera, tetanus). WHO does not recommend routine typhoid and cholera vaccines in endemic areas. Newer typhoid and cholera vaccines have better efficacy, but because they are multi-dose, compliance is likely to be poor. They have not proven effective as a mass public health measure. Vaccination programs require many workers who could be better used elsewhere. Supervision of sterilization and injection techniques may be impossible, potentially causing more harm; mass vaccination may give a false sense of security and neglect other control measures. However, these vaccines are recommended for health workers. Supplying safe drinking water and proper disposal of excreta remain the most practical and effective strategy. Significant tetanus increases have not occurred after natural disasters; mass vaccination against tetanus is usually unnecessary. The best protection is maintaining high routine immunity and proper wound cleaning and treatment. If tetanus immunization occurred more than 5 years ago and there is an open wound, a tetanus toxoid booster is effective. In unimmunized injured patients, tetanus toxoid should be given as part of routine vaccination campaigns in camps with many children.
Disruption of polio and measles vaccination programs should be monitored. If cold-chain facilities are inadequate, requests should be made to improve them. Vaccination policy is decided at senior levels.
Nutrition and Food Security
Disasters may affect nutritional status depending on the disaster type, duration, and pre-existing conditions. Infants, children, pregnant women, nursing mothers, and the sick are especially vulnerable after prolonged droughts or events like hurricanes, floods, landslides, volcanic eruptions, or tsunamis that damage crops or food distribution systems. Immediate steps for effective food relief include: (a) assessing food supplies after the disaster; (b) gauging nutritional needs; (c) calculating daily food rations and needs for large populations; (d) monitoring nutritional status.
Rehabilitation and Environmental Health Measures
Rehabilitation aims to restore pre-disaster conditions. It starts from the earliest moments of a disaster. Rapid external medical care can create expectations that may be difficult to meet later; withdrawal of sophisticated care can leave communities with unmet needs. In the first weeks after a disaster, health needs shift from casualty treatment to routine primary care, and services should be reorganized. Priorities shift from health care to environmental health measures, including:
Water Supply
Survey all public water supplies, including distribution and source.
Assess system integrity, remaining capacities, and bacteriological/chemical quality.
Priority is to disinfect water by chlorination; target residual chlorine level . Low pressure increases risk of contamination.
Repair mains and reservoirs must be cleaned and disinfected.
Identify and analyze potential chemical contaminants.
Protective measures for water sources: restrict access, erect fences, ensure safe excreta disposal, prohibit upstream bathing and animal husbandry, upgrade wells, estimate maximum well yield, ration water if needed.
Water may be trucked; water tankers should be inspected and disinfected before transport.
Food Safety
Poor hygiene is a major cause of foodborne disease in disasters. Kitchen sanitation is critical in feeding programs; monitor personal hygiene of food handlers.
Sanitation and Personal Hygiene
Many communicable diseases spread through fecal contamination of water and food. Emergency latrines should be provided; washing and bathing facilities for displaced persons are essential.
Vector Control
Intensify vector-borne disease control during emergency and rehabilitation periods, especially in known endemic areas. Dengue and malaria (mosquitoes), leptospirosis and rat-bite fever (rats), typhus (lice/fleas), and plague (fleas) are of special concern. Flood waters provide breeding opportunities for mosquitoes.
Child Welfare and Orphans
A major disaster with high mortality leaves displaced populations including orphans who require care. If relatives cannot be found, health and social agencies assume responsibility. Reintegrate survivors quickly through institutional programs coordinated by health ministries, social welfare, education, and NGOs.
Disaster Mitigation in the Health Sector
Emergency prevention and mitigation aim to prevent hazards or lessen effects. Measures include flood mitigation, land-use planning, building codes, and protecting vulnerable populations and structures. Health-sector responsibilities focus on safety of health facilities, water supply, and sewerage systems. Contamination or interruption of water supplies imposes social costs and heavy reconstruction needs; mitigation complements preparedness and response.
Disaster Preparedness
Emergency preparedness is defined as "a programme of long-term development activities whose goals are to strengthen the overall capacity and capability of a country to manage efficiently all types of emergency. It should bring about an orderly transition from relief through recovery, and back to sustained development" (1). The objective is to ensure that systems, procedures and resources are in place to provide prompt effective assistance and to facilitate relief and rehabilitation.
The community as the cornerstone: individuals, communities, organizations, and administration should drive preparedness (2). Reasons for community preparedness include: (a) communities have the most to lose and gain; (b) responders come from within the community; (c) resources are easiest to pool locally; (d) sustained development is best achieved by allowing communities to design and manage assistance programs. Disaster preparedness is an ongoing multisectoral activity forming part of the national system responsible for disaster management across prevention, mitigation, preparedness, response, rehabilitation, and reconstruction. Core tasks across sectors (5):
Evaluate country/region disaster risk;
Adopt standards and regulations;
Organize communication, information and warning systems;
Ensure coordination and response mechanisms;
Ensure availability of resources and financing for readiness and mobilization;
Develop public education programs;
Coordinate information sessions with media;
Organize disaster simulation exercises to test response mechanisms.
Emergency preparedness and management do not exist in a vacuum; programs must be appropriate to context, varying by country and community.
Policy Development and Sectors
Policy development is defined as "the formal statement of a course of action". Policy is strategic, performing functions to:
(a) establish long-term goals;
(b) assign responsibilities for achieving goals;
(c) establish recommended work practices; and
(d) determine criteria for decision making.
Policies tend to be top-down, while implementation of strategies is bottom-up, with support from higher levels. Six sectors are required for response and recovery: communication, health, social welfare, police/security, search and rescue, and transport.
Personal Protection in Emergencies
Personal protection involves ensuring people know what to do in emergencies and take appropriate precautions to aid collective management. Key measures for all types of emergencies include:
Do not use the telephone except to call for help, to keep lines free for responders.
Listen to radio and media for updates.
Follow official instructions from radio or loudspeakers.
Maintain a family emergency kit ready.
In all emergencies, it is better to: be prepared, obtain information to organize, and wait rather than act hastily.
Specific Hazard Guidance: Floods, Storms, Earthquakes, and Toxic Fumes
FLOODS
Before-hand
Town planning is a government responsibility; individuals should know local risks and signals for dam threats. Small floods can be foreseen by watching water levels after heavy rain and through weather forecasts. Hurricanes and cyclones may be announced hours to days in advance.
During
Turn off electricity to reduce electrocution risk.
Protect people and property: move vulnerable people to upper floors; move belongings upstairs where possible.
Beware water contamination; if water looks/smells suspicious, purify it.
Evacuate danger zones as advised; bring emergency supplies.
After
Do not return home until authorities declare it safe.
Ensure water is safe to drink; clean and disinfect flooded rooms; boil water for dishes and utensils.
Dispose of food and consumables that have been in or near floodwater.
STORMS, HURRICANES AND TORNADOES
Before-hand
Know the types of storms in your region, select a shelter in advance (cellar, basement, alcove), minimize damage (remove dead trees, prune branches, check roofs and drainage), take flood-prevention measures, prepare a family emergency kit.
During
Listen to authorities; do not drive during a storm.
Evacuate if advised; take emergency kit.
Secure loose objects; brace doors/windows; prepare for wind loading.
If outdoors, seek shelter; if in a boat, return to shore; avoid fences and electrical cables.
In a thunderstorm, stay away from doors/windows/conductors; unplug electrical devices.
If outside, seek shelter in a building; never shelter under a tree; lie in a ditch if shelter isn’t available.
After
Follow authorities’ instructions; stay indoors; report hazards; ensure water safety; check refrigerators/freezers contents.
EARTHQUAKES
Before-hand
Build according to risk-area regulations; secure electrical and gas appliances and piping; avoid storing heavy items high; hold evacuation drills; prepare a family emergency kit.
During
Stay calm and indoors; move to the building’s central area; avoid stairs.
If outdoors, stay away from buildings and electrical lines; if in a vehicle, park away from bridges/buildings.
After
Obey authorities; do not re-enter damaged buildings; give first aid and report fires or burst pipes; keep a radio handy; ensure water safety and food storage.
CLOUDS OF TOXIC FUMES
Before-hand
Know evacuation plans and alarm signals; reinforce doors/windows; prepare family emergency kits.
During
Do not use telephone; keep lines free for rescue.
Listen to radio and follow instructions; close doors/windows; seal cracks; organize water reserve; turn off ventilators/air conditioning.
After
Comply with authorities; avoid going outside until risk passes; perform decontamination measures as required.
MAN-MADE DISASTERS
Disasters caused by human actions can be categorized as:
(a) Sudden disasters (e.g., Bhopal Gas Tragedy, 3 December 1984): leakage of methyl isocyanate; about people exposed; around deaths. Long-term effects persist.
(b) Insidious disasters: chronic exposure (chemical or radiation exposure) from facilities.
(c) Wars and civil conflicts: modern conflicts disrupt food systems, populations, and infrastructure; latest example cited: the attack on the World Trade Center twin towers (~ deaths). Since World War II there have been about wars and war-related deaths; civilians have comprised more than half of fatalities in many conflicts. Arms race and nuclear weapons have altered public health planning.
Public health response focuses on primary prevention: preventing occurrence and reducing consequences, including tighter regulatory controls on chemical plants, safer plant siting, engineering controls, early warning, and protection against human error.
During early 20th century wars and conflicts, civil defense programs evolved and adapted to nuclear threats, with a shift toward reducing civilian risk and protecting ecosystems.
Disasters in India: Context and Institutional Framework
India is highly disaster-prone in Asia-Pacific, averaging about major natural calamities per year. Common events include floods, cyclones, droughts, earthquakes, and epidemics; major accidents occur in railways, mines, and factories. Northern mountain regions face snow-storms, landslides, and earthquakes; eastern coastal areas face severe floods and cyclones (e.g., Andhra Pradesh, West Bengal, Orissa). Bihar, Assam and Uttar Pradesh experience major floods almost yearly; western deserts face droughts. Notable events include the Orissa super cyclone (29 Oct 1999) with many lives lost and homelessness; the Gujarat earthquake; the 2004 Indian Ocean tsunami; 2013 Kedarnath cloudburst; 2014 floods in Kashmir; 1984 Bhopal disaster. In 1984, methyl isocyanate gas leakage at Union Carbide in Bhopal killed ~ people with long-term health effects.
Administration: In India's federal system, states execute relief, while the central government provides supplementary resources. The central nodal ministry for disaster coordination is the Ministry of Agriculture; health is overseen by the DGHS (Department of Health and Family Welfare), which houses the Emergency Medical Relief Wing coordinating health activities. Public education and community involvement are vital; World Disaster Reduction Day is observed on the second Wednesday of October annually.
Role of agencies and capabilities: The Indian Meteorological Department (IMD) plays a key warning role, with five centres on the east coast and satellite/cyclone-warning capabilities; 31 special observation posts along the east coast; warnings issued to ships; INSAT Disaster Warning System (DWS) receivers are deployed in coastal regions; the Snow and Avalanche Study Establishment (SASE) at Manali issues avalanche warnings 24–48 hours in advance.
International Agencies Providing Health Humanitarian Assistance
Countries in need can receive health humanitarian assistance from multiple sources. Bilateral assistance (personnel, supplies, or cash) is a major source. International/regional agencies include the United Nations: Office for the Coordination of Humanitarian Affairs (OCHA), World Health Organization (WHO), UNICEF, World Food Programme (WFP), Food and Agriculture Organization (FAO). Inter-governmental bodies include the European Community Humanitarian Office (ECHO), Organization of American States (OAS), and regional centers for disaster prevention. Non-governmental organizations (NGOs) include CARE, International Committee of the Red Cross, International Council of Voluntary Agencies (ICVA), and the International Federation of Red Cross and Red Crescent Societies (IFRC).
References (selected)
Coping with major emergencies - WHO strategy and approaches to humanitarian action, Geneva, World Health Organization, 1995.
WHO (1999). Community Emergency Preparedness: a manual for managers and policy-makers, WHO.
Maxy Rosenay, Medicine, 13th Edition, Last (1992), Public Health and Preventive.
WHO (1989). Coping with Natural Disasters: The role of local health personnel and the community.
PAHO (2000). Natural Disasters, Protecting the Public's Health, Scientific Publication No. 575.
Govt. of India (2001). Annual Report 2000-2001, Ministry of Health and Family Welfare, New Delhi.
Note on figures and conventions: Throughout the notes, numerical data from the transcript is preserved and presented in LaTeX within where appropriate to facilitate copying into mathematical contexts or further formatting. Some percentages and counts are cited as approximations (e.g., unacknowledged smaller emergencies for each disaster; mass casualty figures such as exposed in Bhopal; deaths; etc.).