|Disaster Mitigation - 2nd Edition (Department of Humanitarian Affairs/United Nations Disaster Relief Office - Disaster Management Training Programme - United Nations Development Programme , 1994, 64 p.)|
|Part 2 - Actions to reduce risk|
The techniques or measures that an authority might consider in assembling an appropriate package for disaster mitigation can be classified as:
Engineering and construction
Management and institutional
Engineering and construction measures
Engineering measures are of two types. Those that result in stronger individual structures that are more resistant to hazards, and those that create structures whose function is primarily disaster protection - flood control structures, dikes, levees, infiltration dams, etc.
Actions of the first type are mainly actions on individual buildings and structures and are sometimes referred to as 'hardening' facilities against hazard forces. Improving the design and construction of buildings, agricultural structures, infrastructure and other facilities can be achieved in a number of ways. Design standards, building codes and performance specifications are important for facilities designed by engineers. Engineering design against the various hazards may include design for vibration, lateral loads, load surcharges, wind loads, impact, combustibility, flood resistance and other safety factors. Building codes are the critical front line defence for achieving stronger engineered structures, including large private buildings, public sector buildings, infrastructure, transportation networks and industrial facilities.
Disaster-resistance based building codes are unlikely to result in stronger buildings unless the engineers who have to implement the code accept its importance and endorse its use, understand the code and the design criteria required of them and unless the code is fully enforced by authorities through checking and penalizing designs that do not comply. A code has to fit into an environment prepared to receive it. Part of the measures necessary to achieve the 'engineering' mitigation measures may include increased levels of training for engineers and designers, explanatory manuals to interpret the code requirements and the establishment of an effective administration to check code compliance in practice: the recruitment of ten new municipal engineers to enforce an existing code may have more effect in increasing construction quality in a city than proposing higher standards in building codes.
Code enforcement by inspection of structures under construction is an important element of maintaining a strong building stock in hazard-prone areas.
Municipal inspection, Dharan, Yemen Arab Republic
A large number of the buildings likely to be affected in a disaster, and those most vulnerable to hazards are not designed by engineers and will be unaffected by safety standards established in the building codes. These are houses, workshops, storerooms and agricultural buildings built by the owners themselves or by craftsmen or building contractors to their own designs. In many countries these non-engineered buildings make up a large percentage of the total building stock. The 'engineering' measures that are needed to improve the disaster-resistance of non-engineered structures involve the education of builders in practical construction techniques. The resistance of houses to cyclone winds is ultimately dependent on how well the roofing sheets are nailed down, and the quality of the joints in the building frame and its attachment to the ground. Training techniques to teach builders the practicalities of disaster resistant construction are now well understood and form part of the menu of mitigation actions available to the disaster manager.
Training of builders in hazard-resistant construction techniques is best carried out through practical exercises and advice on-site.
Yemen earthquake reconstruction builder training project
Persuading owners and communities to build safer, more disaster-resistant structures and to pay the additional costs involved is required to make builder training effective. The building contractor may play a role in persuading the client to build to higher specifications, but unless this is carried out within a general public awareness of the disaster risk and acceptance of the need for protection, the contractor is unlikely to find many customers. Grant systems, preferential loans and supply of building materials have also been used as incentives to help improve the hazard-resistance of non-engineered buildings. Legalizing land ownership and giving tenants protective rights also encourages people to upgrade building stock with security of tenure and a stake in their own future.
Apart from new buildings, the existing building stock also may need to be 'hardened' against future hazard impacts. The vulnerability of existing buildings can be reduced to some degree by regular maintenance and structural care. Strengthening existing structures ('retrofit' protection) can be achieved through adding bracing, stiffening and new structural elements.
Important existing buildings can be strengthened to reduce their vulnerability to hazards:
Retrofit earthquake-resistant strengthening in Mexico City, Court Tribunal Building
The cost of adding strength to an existing building tends to be more expensive (and disruptive) than making new building design stronger, so strengthening is unlikely to be an economic option for the large majority of the building stock; for average buildings, with relatively short life expectancies (10 to 50 years), it may be better to take a long-term view of building stock upgrading, waiting until buildings come naturally to the end of their useful lives, demolishing them and building new structures in their place that conform to building code safety requirements.
For special structures, critical facilities or historic buildings with long expected life spans, retrofit strengthening techniques are now well established and a considerable amount of expertise has been developed in this field, though these are generally too costly to be useful in development projects
The engineering of large-scale flood control and water-supply measures is complex, lengthy and capital-intensive; and their construction frequently has adverse consequences for those they are intended to protect, for example some people may be forced off their land, land-use patterns may be changed and other adverse effects felt. Experience has shown that small-scale flood control measures which can be managed by community-based organizations can be effective in risk mitigation while simultaneously achieving other development goals. They tend to make use of local materials, labor and management resources to build on traditional mitigation knowledge rather than replacing it, and to enhance the community's own self-reliance rather than undermining it. Such measures can play an important role in disaster-mitigation within integrated agricultural or rural development projects.
Physical planning measures
Many hazards are localized with their likely effects confined to specific known areas: Floods affect flood plains, landslides affect steep soft slopes, etc. The effects can be greatly reduced if it is possible to avoid the hazardous areas being used for settlements or as sites for important structures. Most urban masterplans involving land use zoning probably already attempt to separate hazardous industrial activities from major population centers. Urban planning needs to integrate awareness of natural hazards and disaster risk mitigation into the normal processes of planning the development of a city.
Services provided by one central facility are always more at risk than those provided by several smaller facilities.
Location of public sector facilities is easier to control than private sector location or land use. The careful location of public sector facilities can itself play an important role in reducing the vulnerability of a settlement - schools, hospitals, emergency facilities and major infrastructural elements like water pumping stations, electrical power transformers and telephone exchanges represent a significant proportion of the functioning of a town. An important principle is deconcentration of elements at risk: services provided by one central facility are always more at risk than those provided by several smaller facilities. The collapse of the central telephone exchange in the Mexico City earthquake of 1985 cut communications in the city completely. In the reconstruction, the central exchange was replaced by a number of mini exchanges in different locations around the city to make the telephone system less vulnerable. The same principle applies equally to hospitals and schools, for example as it does to power stations and water treatment plants.
The principle of deconcentration also applies to population densities in a city: a denser concentration of people will always have more disaster potential than if they are more dispersed. Where building densities can be controlled the urban masterplan should reflect the spatial distribution of hazard severity levels in its zoning for permitted densities of development. Indirect control of densities is sometimes possible through simpler methods such as using wide roads, height limitations and road layouts that limit the size of plots available for development. Creation of park lands reduces urban densities, and also provides space in the city, greenery, allows drainage to decrease flood risk, provides refuge areas for the population in the event of urban fires and may provide space for emergency facilities in the event of a disaster.
At a regional level, the concentration of population growth and industrial development in a centralized city is generally less desirable than a decentralized pattern of secondary towns, satellite centers and development spread over a broader region.
The design of service networks - roads, pipelines, and cables also needs careful planning to reduce risk of failure. Long lengths of supply line are at risk if they are cut at any point. Networks that interconnect and allow more than one route to any point are less vulnerable to local failures provided that individual sections can be isolated when necessary. Vehicle access to a specific point is less likely to be cut by a road blockage in a circular road system than in a radial one.
Urban planners may also be able to reduce risks by changing the use of a vulnerable building being used for an important function - a school in a weak building could be moved to a stronger building and the weak building used for a less important function, like storage.
It is often private sector land use, the informal sectors and shanty towns that pose the highest risks of disaster.
The location of public sector facilities is easier to control than those in the private sector. In many rapidly developing cities, the control of private sector land use through urban masterplanning and development permissions is almost impossible. It is often private sector land use, the informal sectors and shanty towns that pose the highest risks of disaster. Hood plains and steep slopes are often the marginal lands that are available to the lower-income communities and the most vulnerable social groups. The economic pressures that drive these groups, first to the city for jobs and opportunity, and second to the marginal lands to live, need to be fully understood as the context for reducing their risk. Prohibition or measures to clear settlers from hazardous areas are unlikely to be successful for long if the background pressures are not addressed. Some indirect measures may be effective, such as making safer land available, or making alternative locations more attractive. This may be through better provision of income sources, access to public transport and better service provision. Deterring further development in unoccupied areas by declaring areas dearly as hazard zones, denying services, reducing accessibility and limiting availability of building materials may also be effective. Ultimately, however, it is only when the local community recognizes the true extent of the hazard and accepts that the risk outweighs the benefit to them of being in that location that they will locate elsewhere or protect themselves in other ways.
A strong economy in which the benefits are shared throughout the society is the best protection against a future disaster.
Equitable economic development is the key to disaster mitigation. A strong economy in which the benefits are shared throughout the society is the best protection against a future disaster. A strong economy means more money to spend on stronger buildings and larger financial reserves to cope with future losses. The interdependency between Disasters and Development is the subject of another module in this training course.
Mitigation measures that help the community reduce future economic losses, help members withstand losses and improve their ability to recover after loss and measures that make it possible for communities to afford higher levels of safety are important elements of an overall mitigation program.
Inevitably it is those who have least that, proportionally, lose most in a disaster. The weakest members of the economy have few economic reserves. If they lose their house or their animals they have no means of recovering them. They are unlikely to have insurance or access to credit and can quickly become destitute. Large scale drought or flood disasters in rural areas can result in an acceleration of urbanization in the region and possibly increased risks as families with their livelihoods destroyed migrate to the towns in search of better opportunities. The destruction of industries and loss of jobs and incomes may well make recovery of the region a long and slow process or make it more vulnerable to a future disaster. Reconstruction plans often extend generous loans to victims to aid their recovery but a family without an income has little prospect of making repayments and is therefore unable to benefit.
Economic development is likely to be the main objective of any regional planner or national government agency, regardless of disaster mitigation objectives. The processes of economic development are complex and beyond the direct focus of this training course, however, disaster mitigation should be seen as a part of the process of economic development.
A single industry (or single-crop) economy is always more vulnerable than an economy made up of many different activities.
Some aspects of economic planning are directly relevant to reducing disaster risk. Diversification of economic activity is as important an economic principle as deconcentration is in physical planning. A single industry (or single-crop) economy is always more vulnerable than an economy made up of many different activities. The linkages between different sectors of an economy - the transportation of goods, the flow of information, the labor market - may be more vulnerable to disruption from a disaster than the physical infrastructure that is the means of production. Tourism as an economic sector is extremely vulnerable to disaster, or even the rumor of a potential disaster. The reliance of industry and the economy on infrastructure - the roads, transportation networks, power, telephone services etc., means that a high priority should be placed on protecting these facilities: the consequential losses of failure are costly to the whole community.
Economic incentives and penalties are an important part of the powers of any authority. Grants, loans, taxes, tax concessions and fines can be used to influence the decisions people make to reduce disaster-related risks. Industrial location is commonly influenced by government incentives which can be used to attract industry to safer locations or to act as a focus for population relocation. Property taxation can be used to penalize more vulnerable structures and structures built in less desirable locations. Grants and loans can be offered to assist owners to upgrade their property and make buildings more disaster resistant.
In industrialized countries, insurance is one of the major economic protection devices. If the risk of economic loss is spread widely over a large number of premium payers, the loss is safely dissipated. Commercial insurance is expensive and its viability is determined by accurate calculation of risk. With only a small number of premium payers, premiums remain high and are prohibitive to potential policy holders. The more widespread policy holding becomes, the lower the premiums are and the more widespread insurance use is likely to be. Encouragement of people to protect themselves through insurance ensures that a level of protection is built up. Compulsory insurance schemes have not been successful and national governments rarely have the financial resources to dedicate to disaster insurance guarantees, although many countries build up a disaster reconstruction fund through general taxation. Disaster insurance is high-risk finance and only multi-national insurance companies can gather the resources to cover the losses of any sizeable disaster. It is unlikely to be available to protect poorer or rural communities and their disaster-protection investments unless backed by a large development agency.
Management and institutional measures
The institutionalization of disaster mitigation requires a consensus of opinion that efforts to reduce disaster risk are of continual importance.
Disaster mitigation also requires certain organizational and procedural measures. The time span over which a significant reduction can be achieved in the potential for disaster is long. Changes in physical planning, upgrading structures and changes in the characteristics of building stock are processes that take decades. The objectives and policies that guide the mitigation processes have to be sustained over a number of years, and have to survive the changes in political administration that are likely to happen within that time, the changes in budgetary priorities and policies on other matters. The institutionalization of disaster mitigation requires a consensus of opinion that efforts to reduce disaster risk are of continual importance.
Education, training and professional competence, and political will, are necessary aspects of institutionalizing disaster mitigation. The professional training of engineers, planners, economists, social scientists and other managers to include hazards and risk reduction within their normal area of competence is gradually becoming common. Increasing the exposure of these groups to international expertise and transfer of technology in disaster mitigation is an important part of building capability in the affected country.
Information is a critical element in planning for disaster mitigation, but there are many hazard-prone countries where the basic meteorological and geological observatories to monitor hazards have not been established or do not have the resources to carry out their job. Research, technical expertise and policy-making organizations are important resources for developing mitigation strategies both nationally and locally.
Administrative and organizational powers for disaster mitigation include the checking procedures and planning powers to realize mitigation plans, consultation procedures and representation of the community in mitigation decisions and management of the implementation of mitigation activities.
Information management and personnel training forms a major part of mitigation activities
Staff of Disaster Preparedness Center, Federal District of Mexico operates computerized emergency database system.
Additional staff resources and organizational structure may be needed to implement mitigation plans. Some countries have established Ministries of Civil Protection or sub-departments whose responsibilities are disaster management and the development of protection measures. It may not be necessary to establish an autonomous unit for disaster mitigation, and it is often argued that disaster mitigation is better integrated within existing activities than carried out as a separate exercise. An administration that carries policy through to implementation is essential.
At the local level, community-based mitigation requires the strengthening of the capability of the local institutions to carry out local protection measures - such training and support can often be carried out most effectively by national or international NGOs.
Community-based mitigation requires the strengthening of the capability of local institutions to formulate plans, to manage local protection measures and to negotiate with government to provide assistance.
A workshop for community leaders in Rimac Valley, Peru, organized by a local NGO in 1985.
Source: Maskrey 1989
The mitigation of disasters will only come about when there is a consensus that it is desirable, feasible and affordable. In many places, the individual hazards that threaten are not recognized, the steps that people can take to protect themselves are not known and the demand of the community to have themselves protected is not forthcoming. Mitigation planning should aim to develop a disaster 'safety culture' in which the people are fully aware of the hazards they face, protect themselves as fully as they can and fully support efforts made on their behalf to protect them.
The objective is to develop an everyday acknowledgment of hazard safety where people take conscious, automatic precautions through being aware of, but not terrified of, the possibility of hazard occurrence.
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. Education should attempt to familiarize and de-sensationalize. Everyone who lives in a hazard-prone area should understand hazards as a fact of life. Information about hazards should be part of the standard curriculum of children at school and be part of everyday information sources, with occasional mentions of them in stories, TV soap operas, newspapers and other common media. The objective is to develop an everyday acknowledgment of hazard safety where people take conscious, automatic precautions through being aware of, but not terrified of, the possibility of hazard occurrence. Their understanding should include being aware of what to do in the event, and a sense that their choice of house, the placement of that bookcase or stove and the quality of construction of the garden wall around their children's play area all affect their own safety.
Awareness of risk locally is aided by reminders of past events: a bollard erected with markings to show the high water mark of past floods; the ruins of a building preserved as a monument to a past earthquake.
It is also important to de-sensationalize hazards. Most occurrences of hazards are not disastrous. Reporting only catastrophic hazards causes fear and fatalism: "If an earthquake lays waste a town, what difference does it make where I put my bookcase?". The treatment of fictional hazards in the media should be aimed at showing how a household copes or doesn't cope with a disruptive occurrence of the hazard, not the annihilation of the soap opera family through cataclysm.
Involvement of the community in mitigation planning processes may involve public meetings and consultations, public inquiries and full discussion of decisions in the normal political forum.
Societal awareness is important for disaster mitigation. Drills and public participation in practices can maintain awareness.
Simulated evacuation of General Hospital Balbuena during a disaster, Mexico City
Further awareness is developed through drills, practice emergencies and anniversary remembrances. In hospitals, schools and large buildings it is often common to have evacuation practices to rehearse what the occupants should do in the event of fire, earthquake or other hazard. In schools children may practice earthquake drills by getting under desks. This reinforces awareness and develops behavioral responses.
In some countries, the anniversary of a major disaster is remembered as Disaster Awareness Day - 1 September in Japan, 20 September in Mexico, and the month of April in California, USA. On this day drills are performed, ceremonies and activities held to promote disaster mitigation. The United Nations General Assembly in its adoption of the International Decade for Natural Disaster Reduction (Resolution 44/236, 22 December 1989) designated the second Wednesday of October as an International Day for Natural Disaster Reduction which may be an opportunity for many other countries to carry out disaster awareness activities.
Disaster awareness can be promoted through national days or months dedicated to hazard-' related exercises. California's Earthquake Preparedness Month in April 1989 involved exercises for business, schools, government and emergency services.
Q. Five types of measures were discussed as being available for planners to use as tools for designing a mitigation program. What are they? Which of these measures are available to you through your office or position?
The five types of mitigation measures discussed in the text are: