RISK AND VULNERABILITY ASSESSMENTS
Disasters occur when natural or technological hazards have an impact on human beings and their environment. Those who have more resources both economic as well as social often have a greater capacity to withstand the effects of a hazard than the poorer members of a society.
· Rapid population growth
· urban or mass migration
· inequitable patterns of land ownership
· lack of education and awareness
· subsistence agriculture on marginal lands
lead to vulnerable conditions such as unsafe siting of buildings and settlements, unsafe homes, deforestation, malnutrition, unemployment, underemployment, and illiteracy.
Displaced people, forced to flee from conflict or collapsing economic conditions, represent a community of sorts that can fall within the purview of vulnerability assessments.
Vulnerability analysis is a continuing, dynamic process of people and organizations assessing the hazards and risks they face and determining what to do.
Individuals and organizations responsible for planning risk reduction and emergency response measures should begin by understanding the nature and probability of occurrence of the hazards that people face. They must assess the societal elements at risk (people, structures, services, and activities) due to these hazards, if and when they occur. Planners should also have a solid grasp of the target population’s specific vulnerabilities and capacities to help them effectively choose and design meaningful risk reduction measures that utilize and build on the target population’s strengths while reducing their vulnerabilities. They must also understand how a society or target population perceives its risks and what importance they place on reduction of specifics risks.
The concepts of vulnerability, hazard, and risk are dynamically related. The relationship of these elements can be expressed as a simple formula that illustrates the concept that the greater the potential occurrence of a hazard and the more vulnerable a population, then the greater the risk. It is also important to note that human vulnerability to disaster is inversely related to human capacity to withstand the effects of disasters.
Risk = Hazards X Vulnerability
Vulnerability: Human vulnerability is the relative lack of capacity of a person or social group to anticipate, cope with, resist, and recover from the impact of a hazard. Vulnerability has two components: exposure to hazards (e.g. drought, earthquake, etc.) and difficulty in coping with and recovering from them (due to lack of resources). Human vulnerability is inversely related to the concept of human capacity.
Structural or physical vulnerability is the extent to which a structure or service is likely to be damaged or disrupted by a hazard event. A building is said to be vulnerable to earthquake tremors if its construction lacks elements which would resist the effects of such tremors.
Capacities: Human capacities are the qualities and resources of an individual or community to anticipate, cope with, resist and recover from the impact of a hazard. According to Mary Anderson's People-Oriented Planning (POP) framework, human capacities include a person's or a community's material resources (food, animals, tools); social and organisational capacities (leadership, community groups); and attitudinal and motivational capacities (ideas, work values, efficacy).
A hazard is defined as the potential occurrence, in a specific time period and geographic area, of a natural phenomenon that may adversely affect human life, property or activity to the extent of causing a disaster. Methods of predicting various hazards and the likelihood and frequency of occurrence vary widely by type of hazard.
Risk refers to the expected or anticipated losses (lives lost, people injured, property damaged, and economic activities or livelihoods disrupted) from the impact of a given hazard on a given element at risk over a specific period of time. Risk is defined differently by people in different situations. Risk, as perceived by the politician or the disaster manager, is different from risk as understood by a scientist, or by an insurance company salesman, or by a family living in an earthquake zone.
Factors affecting human vulnerability
It is important to understand some of the major factors which make a population vulnerable. These factors include:
1. Poverty
2. Increased population density
3. Rapid urbanisation
4. Changes in way of life
5. Environmental degradation
6. Lack of awareness and information
7. War and civil strife
These seven factors frequently are interrelated. For example, poverty often results in people migrating to urban areas in search of work. Limited resources and opportunities in urban areas result in people settling in unsafe locations and can also produce tensions leading to civil unrest.
Poverty
Most disaster studies show that the wealthiest members of a population either survive a disaster unaffected or are able to recover quickly. Poverty generally makes people vulnerable to the impact of hazards. Poverty explains why people in urban areas are forced to live on hills that are prone to landslides or why people settle near volcanoes or rivers that invariably flood their banks. It also explains why famines more often than not are the result of a lack of purchasing power to buy food rather than an absence of food.
Increased population density
There is an obvious connection between the number and magnitude of losses from a disaster and the size of the population. If there are more people and structures where a disaster occurs, then it is likely there will be more of an impact. Population growth means that more people will be forced to live and work in unsafe areas and that more people are competing for a limited number of resources (such as employment opportunities and land), which may lead to conflict.
Rapid urbanization
Rapid population growth and migration are related to the major phenomenon of rapid urbanization. It is characterized by the rural poor or civilians in an area of conflict moving to metropolitan areas in search of economic opportunities and security. As a result, fewer opportunities are available. Competition for scarce resources, an inevitable consequence of rapid urbanization, can result in human-made disasters.
Changes in way of life
All societies are constantly changing and in a continual state of transition. These transitions are often extremely disruptive and uneven and may leave gaps in social coping mechanisms. These transitions include nomadic populations that become sedentary, rural people who move to urban areas, and both rural and urban people who move from one economic level to another. These transitions may also include severe changes in the way a country's economy or political system is managed. Many of the countries in the former Soviet Union have experienced this extreme transition from a centralised economy to a market economy, with a resulting increase in many people's vulnerability.
When people move from rural to urban centres, they may lose the social support system or network that traditionally would have assisted them in recovering from a disaster. Since these traditional coping mechanisms may not exist in the new setting, the population increasingly depends on outside intervention to help in the recovery process. Conflicting as well as transitional cultural practices can lead to civil conflict, for example, as a result of communal violence triggered by religious differences.
Environmental degradation
Many disasters are either caused or exacerbated by environmental degradation. Deforestation leads to rapid rain run off, which contributes to flooding. Companies that engage in mineral extraction often form disposal banks containing toxic substances which may lead to an increase in certain diseases among the population. The creation of drought conditions—and the relative severity and length of time the drought lasts is mainly a natural phenomenon, but agricultural development and the system of food distribution may exacerbate conditions. Similarly, climate changes, which are presumed to be a result of the phenomenon of global warming, may result in more disasters due to such hazards as flooding and desertification.
Lack of awareness and information
Disasters can also happen when people who are vulnerable to them simply do not know how to get out of harm’s way or what protective measures to take. There may be a lack of awareness about what measures can be taken to build safe structures on safe locations. Some people may not know about safe evacuation routes and procedures whereas others may not know where to turn for assistance in times of acute distress. In most disaster-prone societies, however, there is a wealth of understanding about disaster threats and responses. This understanding should be incorporated into external assistance esfforts.
War and civil strife
War and civil strife can be regarded as hazards, that is, extreme events that produce disasters. War and civil strife often result in displaced people who are more vulnerable as a result of their dislocation. Causes of war and civil strife include competition for scarce resources, religious or ethnic intolerance, and ideological differences the same factors that increase vulnerability to disasters.
Perception of risk
Individuals and organizations responsible for designing and implementing effective risk reduction measures must consider how the target population perceives its risks. A detached, scientific or professional assessment of risk, while technically accurate, often will fail to consider the local or target population's perceptions of risk and the choices available to reduce it. While experts like to rely on technical data and statistics, the general public and target populations are less comfortable with these statistical concepts and will base their perceptions on a range of other values, philosophies, concepts and calculations.
Disaster risks are unlikely to be considered important among populations that face much greater everyday threats from disease and food shortages. Even if the disaster risk is quite significant, it is unlikely to compare with the risk of child mortality in a society with a minimal or weakened primary health care system. Where resources and capacities are limited and everyday risks are too great, it becomes difficult to invest time and money in reducing a potential hazard risk.
Populations in disaster-prone areas may also trade-off perceived risks against real or potential benefits. Living near a chemical processing plant may pose certain risks but may also bring the benefit of employment and jobs for the nearby population. To those who choose to live near the plant, the benefits may outweigh the risks of a chemical accident. The risks associated with vaccinations and travelling to work are generally considered acceptable because the benefits are immediately obvious. The levels of acceptable risk appear to increase according to the benefits derived from exposure.
People’s perception of risks may decrease during times of rapid social and technological change or when there are long periods between major disaster events. Organizations such as National Red Cross/Red Crescent Societies can increase a community's awareness by informing the public of potential risks. Programmes to raise awareness are not only useful to increase perceptions of risk, but also to educate the public that risks are preventable and to encourage them to participate in protecting themselves.
· The public perception
· The benefits which may arise
· Other disasters
· Duration between the occurance of the events
Community hazard, risk and capacity mapping
As a way of raising awareness and changing perceptions about potential risks by engaging individuals and groups in producing local community hazard, risk and capacity maps. These maps can be used to:
· Show the general pattern of risks threatening certain population and the capacities they possess for overcoming those risks.
· Highlight local resources and capacities such as skills, food reserves, emergency housing options, community and social organizations, businesses, local leaders, cultural values and attitudes, and transportation sources such as school buses or ox carts that will help communities cope with disasters.
· Hazard maps assist in the preparation of plans which can reduce the danger in a community and in the identification of evacuation plans for risk areas.
The Pan American Health Organization (PAHO) has identified four main steps to produce a community risk and capacity map.
1. Identify and prioritize a list of common problems and needs
2. Visit areas and sites in the community that pose a risk
3. Based on these visits, draw distinct and detailed maps which show potential hazards, vulnerable people and resources in case of emergency. (Ideally, one map is drawn for each: one for the hazards, one for vulnerable people and one for community capacities and resources)
4. Organize a local disaster committee to plan risk reduction measures and/or to formulate a local emergency preparedness and response plan.
Any plans that are generated based on these maps need to be widely discussed and disseminated in a community—ideally through community meetings and presentations. The strategies for reducing risks will also need to be realistic and achievable, lest they raise expectations that cannot be met.
Reducing hazards vs. reducing vulnerability
The construction of levees along the banks of certain rivers reduces the chance of flooding in surrounding areas. It is also possible to prevent potential known landslides and rock falls by stabilizing land pressures, constructing retaining walls and improving the drainage of slopes. Engineering works can contain the destructive agents of some natural hazards or can divert the threat away from important elements with channels and excavation. In some cases, tree planting can be an effective way either to reduce the potential for floods and mudslides or to slow desertification.
The focus of disaster mitigation for these human-made disasters is preventing the hazards from occurring or reducing their impact if they do. Local capacity building measures seek to reduce human vulnerability by building and reinforcing a local community's skills, organizational systems and abilities and offering incentives to reduce risks. They also help communities prepare to respond effectively in case of disasters.
Since members of the local population of disaster-stricken areas are the first ones at the disaster site performing search and rescue activities as well as providing emergency treatment and relief to their families, friends and neighbors organizations such as Red Cross/Red Crescent Societies and the local Civil Defence can play an important role in improving the skills and knowledge of these “spontaneous” disaster responders. Offering education and training in preparedness measures, basic rescue techniques, and first aid and emergency treatment is an important component of risk reduction plans.
Risk reduction measures
The range of risk reduction measures can be classified into the following categories, each of which is discussed below:
1) Societal
2) Physical planning
3) Economic
4) Engineering and construction
5) Management and institutional memory
1) Societal
Risk reduction will occur when there is a consensus that it is desirable, feasible and affordable. Risk reduction planning should aim to develop a “safety culture” in which all members of society are aware of the hazards they face; know how to protect themselves; and will support the protection efforts of others, of society and of the local population as a whole.
Public education campaigns aim to create this safety culture. Public awareness can be raised in a number of ways, from short-term, high profile campaigns using broadcasts, literature and posters, to more long-term, low profile campaigns that are carried out through general education. Planning disaster awareness and disaster preparedness activities in isolation from people's daily lives will rarely succeed. Therefore, these programs are most effective when linked to ongoing and immediate daily community needs such as basic health care, water scarcity and portability, sanitation concerns, employment and community based first aid.
Local involvement in risk reduction planning processes can include public meetings and consultations; public inquiries; full discussion of decisions at special meetings and involvement in generating hazard, risk and capacity maps. Awareness can be developed through regular practice drills, practice emergencies, quizzes and anniversary remembrances. In hospitals, schools and large buildings, it is necessary to rehearse what the occupants should do in the event of a fire, earthquake or other hazard. This reinforces awareness and develops automatic behavioural responses.
Physical planning
Careful location of new facilities particularly community facilities such as schools, hospitals and infrastructure, plays an important role in reducing vulnerability. In urban areas, deconcentration of elements especially at risk is an important principle. That is, services provided by one central facility are always more at risk than those provided by several small facilities. This principle also applies to population density: a denser concentration of people will always increase the potential for disaster compared to a more dispersed population.
Economic
Linkages between different sectors of the economy may be more vulnerable to disruption by a disaster than the physical infrastructure. Diversification of the economy is an important way to reduce risk. A strong economy is the best defense against disaster. Within a strong economy, governments can use economic incentives to encourage individuals or institutions to take disaster mitigation actions.
Engineering
Engineering measures range from large-scale engineering works to strengthening individual buildings and small-scale, community-based projects. Codes of practice for disaster protection (such as building codes) are unlikely to be effective unless they are accepted and understood by the community. Training local builders in techniques that incorporate better protection into traditional structures such as buildings, roads, and embankments is likely to be an essential component of such measures.
Management and institutional
Building disaster-protection takes time. It needs to be supported by a programme of education, training and institution-building to provide the professional knowledge and competence required.
Risk reduction strategies
The general risk reduction strategies often are costly or necessitate enforced legislation and thus will require government, private sector or donor support. The local measures are less costly and promote the use of locally available resources and capacities.
1. Earthquakes
2. Land instabilities
3. Volcanic eruptions
4. Floods and water hazards
5. Storms (typhoons, hurricanes, tropical storms and tornadoes)
6. Droughts and desertification
7. Chemical and industrial accidents
Earthquakes
General risk reduction strategies
There are several hazard mitigation strategies for earthquakes. Structures can be engineered to withstand vibration forces and governments can develop and enforce seismic building codes and higher standards of construction quality. Governments can also ensure that important public sector buildings are constructed according to high engineering design standards. Additional measures can include training programmes to improve construction techniques in the building industry and public education programmes about these techniques. The effects of earthquakes can be mitigated by implementing location planning to reduce urban densities on geological areas known to amplify ground vibrations. In addition, incentives could be offered to remove unsafe buildings or buildings on unsafe sites or, more feasibly, to upgrade their level of safety.
Nearly every country has a means of communicating with its most remotely located citizens, either through the media or through informal communication networks. Public awareness programmes can be designed to reach every vulnerable person and may significantly reduce the social and material costs of an earthquake. Some examples of information to be provided include:
1. causes of earthquakes and warning signs
2. awareness of earthquake risks and ways to minimize personal vulnerability
3. practical ways to reinforce vulnerable houses
4. what to do in the event of an earthquake (with possible participation in a drill)
5. how to form teams to assist in the search for injured people and other post-disaster recovery activities
6. volunteer fire fighting and first aid training
Community-based risk reduction measures
An important element of earthquake mitigation is community awareness and participation. Awareness of earthquake risk and a desire to live in houses safe from seismic forces help motivate construction of earthquake-resistant buildings. Knowledge of what to do in the event of an earthquake can be increased by earthquake drills and public awareness programmes. Community fire fighting, search and rescue, and first aid training groups can also be formed.
Community organisations and local officials should develop plans to prepare and react to the emergency. The plan might include the following elements and activities:
· identifying and training teams for search and rescue operations
· ensuring the rapid availability of detection equipment
· identifying and training teams for disaster assessment
· identifying safe sites and emergency shelters where vulnerable populations could be relocated
· training personnel in trauma care and first aid
· planning for an alternative water supply
· preparing plans to clear streets for emergency access
· preparing emergency communication systems and messages to the public regarding their security
· training teams to determine if buildings are safe for reoccupancy
· preparing flood plans for susceptible areas
· coordinating preparations with voluntary organizations
Land instabilities (including landslides, mud flows, etc)
General risk reduction strategies
A primary mitigation strategy for landslides is location planning to avoid the use of hazardous areas for settlements or as sites for important structures. In addition, landslide risk may be reduced by creating shallower slope angles in hillsides through excavation of the top layers of earth; by increasing deep drainage and surface run-off drainage capacity; and by constructing engineering works such as pilings, ground anchors, and retaining walls. Terracing slopes and reforestation can also prevent loss of surface material. If expected, debris flows can be directed into specially constructed channels and rock fall protection barriers such as trenches; silt dams and vegetation barriers can also be constructed to protect settlements.
Enhancements and protective measures may be added to sites, such as improvement of soil drainage (by addition of permeable materials), slope modifications (reduction of slope angle prior to construction), and re-vegetation of slopes. Concrete retaining walls may stabilize possible sites.
Public education programmes involve descriptions of climatic conditions or hazards that provoke landslides and what actions to take when such conditions exist. Evacuation plans for high risk areas should be established and practiced, particularly when the risk of landslide is interconnected with the threat of seismic, volcanic or flood activity.
Community-based risk reduction measures
The most damaging landslides often occur as a result of the activities of people. Construction of roads, housing, and other infrastructure frequently causes landslides. Thus the most effective preparedness measures are those taken before people occupy a vulnerable area. Public education programmes help people understand the causes and effects of landslides in addition to helping them identify unstable areas and avoid settling there.
Communities should be trained to recognize potential land instabilities, identify active landslide areas, and avoid sitting houses in hazardous locations. Communities can also reduce the risk from land instabilities by constructing structures with strong foundations, compacting ground, preventing deforestation of slopes, stabilizing slopes through terracing and forestry, and creating rock fall barriers using trees and earth banking.
Areas susceptible to landslides may be monitored to allow timely warning and evacuation. Monitoring and warning systems should place inhabitants on alert when heavy rains occur or if ground water levels rise.
Volcanic eruptions
General risk reduction strategies
Potential methods for reducing the impact of volcanic eruptions include location planning to ensure that areas close to volcano slopes are not used for important activities and channeling, damming or diverting lava and debris flows away from settlements through the use of engineering works. Monitoring volcanoes is often feasible and can provide significant lead-time information about volcanic activity. Risks associated with volcanic eruptions can also be reduced by promoting fire-resistant structures as well as engineering structures to withstand the additional weight of ash deposits.
Community-based risk-reduction measures
Communities play an important role in mitigating their risk from volcanic eruptions. Community members should be aware of volcano risk and should identify potential danger zones. In addition, communities and families can prepare and practice evacuation plans. These should include a monitoring and scaled early warning system to alert the local population of eruptions.
Floods and water hazards
General risk reduction strategies
The main risk reduction strategies for floods and water hazards include land-use control and planning to avoid locating vulnerable facilities in flood plains. Retaining walls and levees along rivers and sea walls along coasts may keep high water levels out of flood plains. Structures which are located in flood plains should be engineered to withstand flood forces and designed with elevated floors to reduce damage from flood waters. Dams are capable of storing water so that it can be released at a manageable rate. Levees and dams are subject to failure and can also be damaged by earthquakes. They must be carefully engineered to anticipate maximum water levels since failures may cause much more damage than if the facilities had not been built.
Flood reduction aims to decrease the amount of runoff, usually by altering the watershed, and is most effective when employed over most of the drainage basin. Typical treatments include reforestation or reseeding; contour plowing or terracing; and protection of vegetation from fire, overgrazing and clear-cutting. Other approaches involve clearing sediment and debris from streams, deepening and widening the riverbed and constructing or preserving farm ponds and other water holding areas. In urban areas, water holding areas can be created in parks and ponds.
Community-based risk reduction measures
The majority of deaths and much of the destruction created by floods can be prevented by mitigation and preparedness measures. Where construction in flood-prone sites is necessary or cannot be avoided, houses can be constructed to be flood resistant using materials resistant to water damage and strong foundations. Awareness of water hazards can be reflected in living practices such as constructing elevated storage and sleeping areas. Crop cycles can be modified to avoid the flooding season, and flood-resistant crops can be introduced.
Communities can reduce the risk of personal harm by preparing flood evacuation plans which include the identification of evacuation routes and availability of boats or other appropriate transport and rescue equipment. Monitoring and warning systems at the local (and regional) level are also important components of a risk reduction strategy.
Some aspects of flood planning and response can be managed at the village level and upgraded with outside assistance. These are:
· issuing warnings at the local level
· Participating in flood fighting by organizing work parties to repair embankments or clear debris from drainage areas, pile sandbags and stockpile needed materials.
· facilitating agricultural recovery
· planning emergency supplies of food and clean drinking water
· identifying traditional mitigation and preparedness measures and determining their effectiveness
Programmes to promote public awareness of flood hazards may contain the following components:
· Explanations of the function of flood plains, location of local flood plains and drainage patterns
· Identification of flood hazard and warning signs
· Advice on how to flood-proof possessions and develop personal escape plans
· Explanation of local evacuation plans and warning systems, and appropriate post disaster activities
· Emphasis on personal responsibility for flood prevention/mitigation in day-to-day living practices. This includes the use of proper farming practices, prevention of deforestation and maintenance of drainage systems
· Provision of escape routes—neighbourhoods should have clear escape routes and designated areas of refuge on higher ground
· Evacuation procedures should be practised on a regular basis and ways to disseminate warnings via radio, television, warning sirens or bells should be devised
Storms (typhoons, hurricanes, tropical storms and tornadoes)
General risk reduction strategies
The main mitigation strategies for hazards due to storms include a public that is well informed regarding the hazard and an effective warning system. Engineering structures to withstand wind forces, developing wind load requirements in building codes and wind safety requirements for non-structural elements are also important. In addition, siting key facilities in less vulnerable areas (such as in the lee of hillsides), planting windbreaks, and planning forestry areas upwind of towns can also reduce the risks associated with storms. Strong, wind-safe public buildings which can be used for community shelter in vulnerable settlements can also reduce the risk to community members whose homes are not safe in storms. Crops can be protected by introducing agricultural practices and crops which are more resistant to high winds.
Community-based risk reduction measures
Communities can help reduce their risk of damage from storms by preparing evacuation plans and warning systems to be implemented in the event of a storm; by constructing wind-resistant or easily rebuilt houses; by securing and fastening down those elements that could blow away and cause damage or injury elsewhere, such as metal sheeting, fences, and signs; by taking shelter in strong, wind-resistant buildings; by taking protective measures for boats, building contents or other possessions at risk; and by protecting food storage facilities from storms.
Drought and desertification
General risk reduction strategies
Drought and desertification can be reduced by improved land and water management practices, such as water conservation practices, infiltration dams, irrigation, forest management, and range management (control of land use and animal grazing patterns).
The main risk reduction strategies for drought and desertification include rationing water; conserving or replacing failing water supplies through watershed management and construction of dams, pipelines or aqueducts; conserving soil and reducing erosion rates by using check dams, leveling, planting, and managing herds; reducing firewood cutting by using improved fuel stoves; introducing flexible farming and cropping patterns; raising awareness about the benefits of population control; and developing education and training programmes.
Community-based risk reduction measures
Communities can construct check dams, reservoirs, wells and water tanks as well as develop planting and re-forestation efforts to reduce the risks of drought and desertification. They can also change cropping patterns and livestock management practices, introduce water conservation policies, build sturdier wells, start dry-season well-irrigated gardens and develop alternative non-agricultural industries.
Chemical and industrial accidents
General risk reduction strategies
Technological hazards can be reduced by improving safety standards in plant and equipment design, by anticipating possible hazards in plant design, by developing safe design and operating procedures, by safe and regulated disposal of hazardous materials, and through proper preparedness planning. In addition risk reduction strategies include using fire-resistant materials, building fire barriers or installing devices to extract smoke, improving detectors and warning systems, engaging in preparedness planning by improving fire fighting and pollution dispersal capabilities, and emergency relief and evacuation planning for plant employees and nearby settlements (crew and passengers in the case of vehicles). In addition, on-site and off-site safety plans should be initiated and drills should be conducted in conjunction with local fire departments and other civil authorities.
The effects of a technological disaster may be reduced by providing accurate inventories and maps of storage locations of toxic/hazardous substances and their characteristics to those responding to technological disasters.
Community-based risk reduction measures
Communities should participate in actions to monitor pollution levels, ensure inspection and enforcement of existing safety standards, and improve safety legislation. They should also develop evacuation plans to be followed in the event of a technological disaster as well as regulate hazardous-materials transport routes away from schools and residential areas. Local leaders and officials also have a role to play with regard to chemical and industrial accidents. They represent the concerns or views of their constituents. Their responsibilities include:
· Communicating with local authorities and industry leaders regarding issues of concern to the local population
· Communicating with their constituency on programmes related to protecting public health and the environment
· Encouraging locally based organisations to participate in and conduct safety and preparedness training
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