Previous PageTable of Contents Next Page




This chapter defines natural hazards and their relationship to natural resources (they are negative resources), to environment (they are an aspect of environmental problems), and to development (they are a constraint to development and can be aggravated by it). The chapter demonstrates that the means of reducing the impact of natural hazards is now available. The factors that influence susceptibility to vulnerability reduction-the nature of the hazard, the nature of the study area, and institutional factors-are discussed. The core of the chapter explains how to incorporate natural hazard management into the process of integrated development planning, describing the process used by the OAS-Study Design, Diagnosis, Action Proposals, Implementation-and the hazard management activities associated with each phase. The chapter goes on to show how the impact of natural hazards on selected economic sectors can be reduced using energy, tourism, and agriculture as examples. Finally, the significance of a hazard management program to national and international development institutions is discussed.

The planning process in development areas does not usually include measures to reduce hazards, and as a consequence, natural disasters cause needless human suffering and economic losses. From the early stages, planners should assess natural hazards as they prepare investment projects and should promote ways of avoiding or mitigating damage caused by floods, earthquakes, volcanic eruptions, and other natural catastrophic events. Adequate planning can minimize damage from these events. It is hoped that familiarizing planners with an approach for incorporating natural hazard management into development planning can improve the planning process in Latin America and the Caribbean and thereby reduce the impact of natural hazards.


1. How Natural Are Natural Hazards?
2. Environment, Natural Hazards and Sustainable Development
3. The Impact of Natural Hazards Can Be Reduced

A widely accepted definition characterizes natural hazards as "those elements of the physical environment, harmful to man and caused by forces extraneous to him" (Burton, 1978). More specifically, in this document, the term "natural hazard" refers to all atmospheric, hydrologic, geologic (especially seismic and volcanic), and wildfire phenomena that, because of their location, severity, and frequency, have the potential to affect humans, their structures, or their activities adversely. The qualifier "natural" eliminates such exclusively manmade phenomena as war, pollution, and chemical contamination. Hazards to human beings not necessarily related to the physical environment, such as infectious disease, are also excluded from consideration here. Figure 1-1 presents a simplified list of natural hazards, and the boxes on the following pages briefly summarize the nature of geologic hazards, flooding, tsunamis, hurricanes, and hazards in arid and semi-arid areas.

1. How Natural Are Natural Hazards?

Not with standing the term "natural," a natural hazard has an element of human involvement. A physical event, such as a volcanic eruption, that does not affect human beings is a natural phenomenon but not a natural hazard. A natural phenomenon that occurs in a populated area is a hazardous event. A hazardous event that causes unacceptably large numbers of fatalities and/or overwhelming property damage is a natural disaster. In areas where there are no human interests, natural phenomena do not constitute hazards nor do they result in disasters. This definition is thus at odds with the perception of natural hazards as unavoidable havoc wreaked by the unrestrained forces of nature. It shifts the burden of cause from purely natural processes to the concurrent presence of human activities and natural events.



Tropical storms


Fault ruptures
Ground shaking
Lateral spreading


Debris avalanches
Expansive soils
Rock falls
Submarine slides


Coastal flooding
Erosion and sedimentation
River flooding
Storm surges


Tephra (ash, cinders, lapilli)
Lava flows
Projectiles and lateral blasts
Pyroclastic flows



Although humans can do little or nothing to change the incidence or intensity of most natural phenomena, they have an important role to play in ensuring that natural events are not converted into disasters by their own actions. It is important to understand that human intervention can increase the frequency and severity of natural hazards. For example, when the toe of a landslide is removed to make room for a settlement, the earth can move again and bury the settlement. Human intervention may also cause natural hazards where none existed before. Volcanoes erupt periodically, but it is not until the rich soils formed on their eject are occupied by farms and human settlements that they are considered hazardous. Finally, human intervention reduces the mitigating effect of natural ecosystems. Destruction of coral reefs, which removes the shore's first line of defense against ocean currents and storm surges, is a clear example of an intervention that diminishes the ability of an ecosystem to protect itself. An extreme case of destructive human intervention into an ecosystem is desertification, which, by its very definition, is a human-induced "natural" hazard.

All this is the key to developing effective vulnerability reduction measures: if human activities can cause or aggravate the destructive effects of natural phenomena, they can also eliminate or reduce them.

2. Environment, Natural Hazards and Sustainable Development

The work of the OAS/DRDE is focused upon helping countries plan spatial development and prepare compatible investment projects at a prefeasibility level. In a general sense, these tasks may be called "environmental planning"; they consist of diagnosing the needs of an area and identifying the resources available to it, then using this information to formulate an integrated development strategy composed of sectoral investment projects. This process uses methods of systems analysis and conflict management to arrive at an equitable distribution of costs and benefits, and in doing so it links the quality of human life to environmental quality. In the planning work, then, the environment-the structure and function of the ecosystems that surround and support human life-represents the conceptual framework. In the context of economic development, the environment is that composite of goods, services, and constraints offered by surrounding ecosystems. An ecosystem is a coherent set of interlocking relationships between and among living things and their environments. For example, a forest is an ecosystem that offers goods, including trees that provide lumber, fuel, and fruit. The forest may also provide services in the form of water storage and flood control, wildlife habitat, nutrient storage, and recreation. The forest, however, like any physical resource, also has its constraints. It requires a fixed period of time in which to reproduce itself, and it is vulnerable to wildfires and blights. These vulnerabilities, or natural hazards, constrain the development potential of the forest ecosystem.


Earthquakes are caused by the sudden release of slowly accumulated strain energy along a fault in the earth's crust, Earthquakes and volcanoes occur most commonly at the collision zone between tectonic plates. Earthquakes represent a particularly severe threat due to the irregular time intervals between events, lack of adequate forecasting, and the hazards associated with these:

- Ground shaking is a direct hazard to any structure located near the earthquake's center. Structural failure takes many human lives in densely populated areas.

- Faulting, or breaches of the surface material, occurs as the separation of bedrock along lines of weakness.

- Landslides occur because of ground shaking in areas having relatively steep topography and poor slope stability.

. - Liquefaction of gently sloping unconsolidated material can be triggered by ground shaking. Rows and lateral spreads (liquefaction phenomena) are among the most destructive geologic hazards.

- Subsidence or surface depressions result from the settling of loose or unconsolidated sediment. Subsidence occurs in waterlogged soils, fill, alluvium, and other materials that are prone to settle.

- Tsunamis or seismic sea waves, usually generated by seismic activity under the ocean floor, cause flooding in coastal areas and can affect areas thousands of kilometers from the earthquake center.


Volcanoes are perforations in the earth's crust through which molten rock and gases escape to the surface. Volcanic hazards stem from two classes of eruptions:

- Explosive eruptions which originate in the rapid dissolution and expansion of gas from the molten rock as it nears the earth's surface. Explosions pose a risk by scattering rock blocks, fragments, and lava at varying distances from the source.

- Effusive eruptions where material flow rather than explosions is the major hazard. Flows vary in nature (mud, ash, lava) and quantity and may originate from multiple sources. Flows are governed by gravity, surrounding topography, and material viscosity.

Hazards associated with volcanic eruptions include lava flows, falling ash and projectiles, mudflows, and toxic gases. Volcanic activity may also trigger other natural hazardous events including local tsunamis, deformation of the landscape, floods when lakes are breached or when streams and rivers are dammed, and tremor-provoked landslides.


The term landslide includes slides, falls, and flows of unconsolidated materials. Landslides can be triggered by earthquakes, volcanic eruptions, soils saturated by heavy rain or groundwater rise, and river undercutting. Earthquake shaking of saturated soils creates particularly dangerous conditions. Although landslides are highly localized, they can be particularly hazardous due to their frequency of occurrence. Classes of landslide include:

- Rockfalls, which are characterized by free-falling rocks from overlying cliffs. These often collect at the cliff base in the form of talus slopes which may pose an additional risk.

- Slides and avalanches, a displacement of overburden due to shear failure along a structural feature. If the displacement occurs in surface material without total deformation it is called a slump.

- Flows and lateral spreads, which occur in recent unconsolidated material associated with a shallow water table. Although associated with gentle topography, these liquefaction phenomena can travel significant distances from their origin.

The impact of these events depends on the specific nature of the landslide. Rockfalls are obvious dangers to life and property but, in general, they pose only a localized threat due to their limited areal influence. In contrast, slides, avalanches, flows, and lateral spreads, often having great areal extent, can result in massive loss of lives and property. Mudflows, associated with volcanic eruptions, can travel at great speed from their point of origin and are one of the most destructive volcanic hazards.

A survey of environmental constraints, whether focused on urban, rural, or wildland ecosystems, includes (1) the nature and severity of resource degradation; (2) the underlying causes of the degradation, which include the impact of both natural phenomena and human use; and (3) the range of feasible economic, social, institutional, policy, and financial interventions designed to retard or alleviate degradation. In this sense, too, natural hazards must be considered an integral aspect of the development planning process.

Recent development literature sometimes makes a distinction between "environmental projects" and "development projects." "Environmental projects" include objectives such as sanitation, reforestation, and flood control, while "development projects" may focus on potable water supplies, forestry, and irrigation. But the project-by-project approach is clearly an ineffective means of promoting socioeconomic well-being. Development projects, if they are to be sustainable, must incorporate sound environmental management. By definition, this means that they must be designed to improve the quality of life and to protect or restore environmental quality at the same time and must also ensure that resources will not be degraded and that the threat of natural hazards will not be exacerbated. In short, good natural hazard management is good development project management.

Indeed, in high-risk areas, sustainable development is only possible to the degree that development planning decisions, in both the public and private sectors, address the destructive potential of natural hazards. This approach is particularly relevant in post-disaster situations, when tremendous pressures are brought to bear on local, national, and international agencies to replace, frequently on the same site, destroyed facilities. It is at such times that the pressing need for natural hazard and risk assessment information and its incorporation into the development planning process become most evident.

To address hazard management, specific action must be incorporated into the various stages of the integrated development planning study: first, an assessment of the presence and effect of natural events on the goods and services provided by natural resources in the plan area; second, estimates of the potential impact of natural events on development activities; and third, the inclusion of measures to reduce vulnerability in the proposed development activities. Within this framework, "lifeline" networks should be identified: components or critical segments of production facilities, infrastructure, and support systems for human settlements, which should be as nearly invulnerable as possible and be recognized as priority elements for rehabilitation following a disaster.

3. The Impact of Natural Hazards Can Be Reduced

Experiences both in and out of Latin American and the Caribbean show that the record of hazard mitigation is improving. The installation of warning systems in several Caribbean countries has reduced the loss of human life due to hurricanes. Prohibition of permanent settlement in floodplains, enforced by selective insurance coverage, has significantly reduced flood damage in many vulnerable areas.

In the field of landslide mitigation, a study in the State of New York (U.S.A.) showed that improved procedures from 1969 to 1975 reduced the cost of repairing landslide damage to highways by over 90 percent (Hays, 1981). Experience of the city of Los Angeles, California, indicates that adequate grading and soil analysis ordinances can reduce landslide losses by 97 percent (Petak and Atkisson, 1982).

A study in the San Fernando Valley, California, after the 1971 earthquake showed that of 568 older school buildings that did not satisfy the requirements of the Field Act (a law stipulating design standards), 50 were so badly damaged that they had to be demolished. But all of the 500 school buildings that met seismic-resistance standards suffered no structural damage (Bolt, 1988). The Loma Prieta earthquake in 1989 was the costliest natural disaster in U.S. history, but provisions in local zoning and building codes kept it from being even worse. In the San Francisco Bay area post-1960 structures swayed but stayed intact, while older buildings did not fare nearly as well. Unreinforced masonry structures suffered the worst damage. Buildings on solid ground were less likely to sustain damage than those constructed on landfill or soft mountain slopes (King, 1989).

Mitigation techniques can also lengthen the warning period before a volcanic eruption, making possible the safe evacuation of the population at risk. Sensitive monitoring devices can now detect increasing volcanic activity months in advance of an eruption. Still more sophisticated assessment, monitoring, and alert systems are becoming available for volcanic eruption, hurricane, tsunami, and earthquake hazards.

Sectoral hazard assessments conducted by the OAS of, among others, energy in Costa Rica and agriculture in Ecuador have demonstrated the savings in capital and continued production that can be realized with very modest investments in the mitigation of natural hazard threats through vulnerability reduction and better sectoral planning.


Two types of flooding can be distinguished: (1) land-borne floods, or river flooding, caused by excessive run-off brought on by heavy rains, and (2) sea-borne floods, or coastal flooding, caused by storm surges, often exacerbated by storm run-off from the upper watershed. Tsunamis are a special type of sea-borne flood.

a. Coastal flooding

Storm surges are an abnormal rise in sea water level associated with hurricanes and other storms at sea. Surges result from strong on-shore winds and/or intense low pressure cells and ocean storms. Water level is controlled by wind, atmospheric pressure, existing astronomical tide, waves and swell, local coastal topography and bathymetry, and the storm's proximity to the coast.

Most often, destruction by storm surge is attributable to:

- Wave impact and the physical shock on objects associated with the passing of the wave front.
- Hydrostatic/dynamic forces and the effects of water lifting and carrying objects.

The most significant damage often results from the direct Impact of waves on fixed structures. Indirect impacts include flooding and undermining of major infrastructure such as highways and railroads.

Hooding of deltas and other low-lying coastal areas is exacerbated by the influence of tidal action, storm waves, and frequent channel shifts.

b. River flooding

Land-borne floods occur when the capacity of stream channels to conduct wafer is exceeded and water overflows banks. Floods are natural phenomena, and may be expected to occur at irregular intervals on all stream and rivers. Settlement of floodplain areas is a major cause of flood damage.


Tsunamis are long-period waves generated by disturbances such as earthquakes, volcanic activity, and undersea landslides. The crests of these waves can exceed heights of 25 meters on reaching shallow water. The unique characteristics of tsunamis (wave lengths commonly exceeding 100 km, deep-ocean velocities of up to 700 km/hour, and small crest heights in deep water) make their detection and monitoring difficult. Characteristics of coastal flooding caused by tsunamis are the same as those of storm surges.


Hurricanes are tropical depressions which develop into severe storms characterized by winds directed inward in a spiraling pattern toward the center. They are generated over warm ocean water at low latitudes and are particularly dangerous due to their destructive potential, large zone of influence, spontaneous generation, and erratic movement. Phenomena which are associated with hurricanes are:

- Winds exceeding 64 knots (74 mi/hr or 118 km/hr), the definition of hurricane force. Damage results from the wind's direct impact on fixed structures and from wind-borne objects.

- Heavy rainfall which commonly precedes and follows hurricanes for up to several days. The quantity of rainfall is dependent on the amount of moisture in the air, the speed of the hurricane's movement, and its size. On land, heavy rainfall can saturate soils and cause flooding because of excess runoff (land-borne flooding); it can cause landslides because of added weight and lubrication of surface material; and/or it can damage crops by weakening support for the roots.

- Storm surge (explained above), which, especially when combined with high tides, can easily flood low-lying areas that are not protected.

Hazards in Arid and Semi-Arid Areas

a. Desertification

Desertification, or resource degradation in arid lands that creates desert conditions, results from interrelated and interdependent sets of actions, usually brought on by drought combined with human and animal population pressure. Droughts are prolonged dry periods in natural climatic cycles. The cycles of dry and wet periods pose serious problems for pastoralists and farmers who gamble on these cycles. During wet periods, the sizes of herds are increased and cultivation is extended into drier areas. Later, drought destroys human activities which have been extended beyond the limits of a region's carrying capacity.

Overgrazing Is a frequent practice In dry lands and is the single activity that most contributes to desertification. Dry-land farming refers to rain-fed agriculture In semiarid regions where water is the principal factor limiting crop production. Grains and cereals are the most frequently grown crops. The nature of dry-land farming makes it a hazardous practice which can only succeed if special conservation measures such as stubble mulching, summer fallow, strip cropping, and clean tillage are followed. Desertified dry lands in Latin America can usually be attributed to some combination of exploitative land management and natural climate fluctuations.

b. Erosion and Sedimentation

Soil erosion and the resulting sedimentation constitute major natural hazards that produce social and economic losses of great consequence. Erosion occurs in all climatic conditions, but is discussed as an arid zone hazard because together with salinization, it is a major proximate cause of desertification. Erosion by water or wind occurs on any sloping land regardless of its use. Land uses which increase the risk of soil erosion Include overgrazing, burning and/or exploitation of forests, certain agricultural practices, roads and trails, and urban development. Soil erosion has three major effects: loss of support and nutrients necessary for plant growth; downstream damage from sediments generated by erosion; and depletion of the water storage capacity, because of soil loss and sedimentation of streams and reservoirs, which results in reduced natural stream flow regulation.

Stream and reservoir sedimentation is often the root of many water management problems. Sediment movement and subsequent deposition in reservoirs and river beds reduces the useful lives of water storage reservoirs, aggravates flood water damage, impedes navigation, degrades water quality, damages crops and infrastructure, and results in excessive wear of turbines and pumps.

c. Salinization

Saline water is common in dry regions, and soils derived from chemically weathered marine deposits (such as shale) are often saline. Usually, however, saline soils have received salts transported by water from other locations. Salinization most often occurs on irrigated land as the result of poor water control, and the primary source of salts impacting soils is surface and/or ground water. Salts accumulate because of flooding of low-lying lands, evaporation from depressions having no outlets, and the rise of ground water close to soil surfaces. Salinization results in a decline in soil fertility or even a total loss of land for agricultural purposes. In certain instances, farmland abandoned because of salinity problems may be subjected to water and wind erosion and become desertified.

Inexpensive water usually results in over-watering. In dry regions, salt-bearing ground water is frequently the major water resource. The failure to properly price water from irrigation projects can create a great demand for such projects and result in misuse of available water, causing waterlogging and salinization.

However, much remains to be done. The overall record of hazard management in Latin America and the Caribbean is unimpressive for a number of reasons-among them lack of awareness of the issue, lack of political incentive, and a sense of fatalism about "natural" disasters. But techniques are becoming available, experiences are being analyzed and transmitted, the developing countries have demonstrated their interest, and the lending agencies are discussing their support. If these favorable tendencies can be encouraged, significant reduction of the devastating effects of hazards on development in Latin America and the Caribbean is within reach.


1. The Nature of the Hazard
2. The Nature of the Study Area
3. The Participants in the Drama

1. The Nature of the Hazard

a. Rapid Onset vs. Slow Onset
b. Controllable Events vs. Immutable Events
c. Frequency vs. Severity
d. Mitigation Measures to Withstand Impact vs. Mitigation Measures to Avoid Impact

a. Rapid Onset vs. Slow Onset

The speed of onset of a hazard is an important variable since it conditions warning time. At one extreme earthquakes, landslides, and flash floods give virtually no warning. Less extreme are tsunamis, which typically have warning periods of minutes or hours, and hurricanes and floods, where the likelihood of occurrence is known for several hours or days in advance. Volcanoes can erupt suddenly and surprisingly, but usually give indications of an eruption weeks or months in advance. (Colombia's Volcán Ruiz gave warnings for more than a year before its destructive eruption in 1985.) Other hazards such as drought, desertification, and subsidence act slowly over a period of months or years. Hazards such as erosion/sedimentation have varying lead times: damage may occur suddenly as the result of a storm or may develop over many years.

b. Controllable Events vs. Immutable Events

For some types of hazards the actual dimensions of the occurrence may be altered if appropriate measures are taken. For others, no known technology can effectively alter the occurrence itself. For example, channelizing a stream bed can reduce the areal extent of inundations, but nothing will moderate the ground shaking produced by an earthquake.

c. Frequency vs. Severity

Where flooding occurs every year or every few years, the hazard becomes part of the landscape, and projects are sited and designed with this constraint in mind. Conversely, in an area where a tsunami may strike any time in the next 50 or 100 years, it is difficult to stimulate interest in vulnerability reduction measures even though the damage may be catastrophic. With so long a time horizon, investment in capital intensive measures may not be economically viable. Rare or low-probability events of great severity are the most difficult to mitigate, and vulnerability reduction may demand risk-aversion measures beyond those justified by economic analysis.

d. Mitigation Measures to Withstand Impact vs. Mitigation Measures to Avoid Impact

Earthquake-resistant construction and floodproofing of buildings are examples of measures that can increase the capacity of facilities to withstand the impact of a natural hazard. Measures such as zoning ordinances, insurance, and tax incentives, which direct uses away from hazard-prone areas, lead to impact avoidance.

2. The Nature of the Study Area

The high density of population and expensive infrastructure of cities makes them more susceptible to the impacts of natural events. Mitigation measures are both more critically needed and more amenable to economic justification than in less-developed areas. Urban areas are likely to have or are able to establish the institutional arrangements necessary for hazard management.

For small towns and villages non-structural mitigation measures may be the only affordable alternative. Such settlements rely on the government to only a limited extent for warning of an impending hazard or assistance in dealing with it. Thus organizing the local community to cope with hazards is a special aspect of hazard management.

The physical characteristics of the land, land-use patterns, susceptibility to particular hazards, income level, and cultural characteristics similarly condition the options of an area in dealing with natural hazards.

3. The Participants in the Drama

Among the "actors" involved in the process of hazard management are planning agencies, line ministries, emergency preparedness and response centers, the scientific and engineering community, local communities, technical assistance agencies, development finance agencies, and non-governmental organizations, not to mention the equally diverse list of private-sector players. Each has its own interests and approach. These varied and sometimes conflicting viewpoints can add to the constraints of planning and putting into operation a hazard management program, but having advance knowledge of the difficulties each may present can help the practitioner deal with them.

Planning agencies are often unfamiliar with natural hazard information, or how to use it in development planning.

Line ministries similarly have little familiarity with natural hazard information or with the techniques of adapting it for use in planning. Projects for the development of road, energy, telecommunications, irrigation systems, etc., often lack hazard mitigation consideration. Furthermore, ministries tend to have little experience in collaborating with each other to identify the interrelationships between projects or to define common information requirements so that information that suits the needs of many users can be collected cooperatively.

The emergency preparedness community has tended to view its role exclusively as preparing for and reacting to emergencies and has therefore neglected linking preparedness to long-term mitigation issues. Furthermore, emergency centers have paid insufficient attention to the vulnerability of their own infrastructure. When these lifeline facilities are wiped out, disaster victims have nowhere to turn. Emergency preparedness policies are beginning to change. For example, international emergency relief organizations such as the International League of Red Cross and Red Crescent Societies have stated that they will devote more effort in developing countries to prevention.

The scientific and engineering community often sets its agenda for research and monitoring on the basis of its own scientific interests without giving due consideration to the needs of vulnerability reduction or emergency preparedness. For example, a volcano may be selected for monitoring because of its scientific research value rather than its proximity to population centers. Valuable information on hazards is often published in scientific journals in abstruse language. The scientific community should ensure that data are translated into a form suitable for use by hazard management practitioners.

Local communities are jarringly aware of the impact of natural hazards. But they usually have little opportunity to participate in the preparation of large infrastructure and production projects that impinge on them, and even less in setting agendas for natural hazard assessment and vulnerability reduction.

Technical cooperation agencies do not normally include natural hazard assessment and vulnerability reduction activities as a standard part of their project preparation process. "Hazard impact statements" that, like environmental impact statements, are conducted after the project is formulated, are not adequate. Hazard considerations must be introduced earlier in the process so that projects are prepared with these constraints in mind.

Development financing agencies engage actively in post-disaster reconstruction measures, yet do not insist on hazard assessment, mitigation, and vulnerability reduction measures in their ordinary (non-disaster-related) development loans, and are reluctant to incorporate such considerations into project evaluation.

Other institutional considerations: Knowledge of and experience with hazard management techniques are rare commodities in most agencies in Latin America and the Caribbean. Thus, if a technical cooperation agency proposes to incorporate these ideas into planning and project formulation, it invariably has to overcome the skepticism of the relevant local personnel. This adds to the cost of formulating a project, but the extra cost can pay high dividends.

Greater consideration should be given to the private sector, as is pointed out by Andrew Natsios (1990) in "Disaster Mitigation and Economic Incentives." Natsios, following Charles Schultze, claims that policy-makers can change social behavior more effectively by changing the incentives of the marketplace, i.e., the public use of private interest, than by regulation. For example, casualty insurance companies could offer a large premium differential for earthquake- and hurricane-resistant construction. He suggests that governments should specify the desired outcome of policy, but leave the method of achieving that outcome to the economic actors.

At the national level, giving a single entity total responsibility for hazard management tends to cause other agencies to see it as an adversary. Instead, each agency that formulates projects as part of its standard activities should appreciate the importance of introducing hazard considerations into the process of project formulation. Planning agencies should take an advocacy position on hazard management and on introducing non-structural mitigation strategies early in the planning process. Such agencies should have personnel trained for these functions.

Similarly, at the project level responsibility for mitigating the impact of natural hazards does not lie with a single individual or component but is an overall responsibility of the project, requiring the cooperation of all components.

Post-disaster reconstruction activities often lack support for hazard assessments intended to ensure characterize potential hazardous events. Ideally, a natural hazard assessment promotes an awareness of the issue in a developing region, evaluates the threat of natural hazards, identifies the additional information needed for a definitive evaluation, and recommends appropriate means of obtaining it. that the impact of the next event is less destructive. The problem lies with both the lender and the recipient: the stricken country rarely includes this item in its request, but when it does, the lending agencies often reject it. Reconstruction projects, especially when they are very large, are often managed by newly created implementation agencies. This results in a drain of the already limited supply of technical personnel from the existing agencies and complicates coordination between long-term development and short-term rehabilitation.


1. Hazard Management Activities
2. Incorporating Mitigation Measures into the Stages of an Integrated Development Planning Study
3. Advantages of Integrated Development Planning for Natural Hazard Management

For purposes of this discussion, development planning is considered the process by which governments produce plans-consisting of policies, projects, and supporting actions-to guide economic, social, and spatial development over a period of time. The hazard management process consists of a number of activities designed to reduce loss of life and destruction of property. Natural hazard management has often been conducted independently of development planning. A distinctive feature of OAS technical assistance is the integration of the two processes.

1. Hazard Management Activities

a. Disaster Mitigation
b. Natural Hazard Prediction
c. Emergency Preparedness
d. Disaster Rescue and Relief
e. Post-Disaster Rehabilitation and Reconstruction
f. Education and Training Activities

The natural hazard management process can be divided into pre-event measures, actions during and immediately following an event, and post-disaster measures. In approximate chronological order these are as follows:

1. Pre-event Measures:

a. Mitigation of Natural Hazards:

- Data Collection and Analysis
- Vulnerability Reduction

b. Preparation for Natural Disasters

- Prediction
- Emergency Preparedness (including monitoring, alert, evacuation)
- Education and Training

2. Measures During and Immediately After Natural Disasters:

a. Rescue
b. Relief

3. Post-disaster Measures:

a. Rehabilitation
b. Reconstruction

a. Disaster Mitigation

An accurate and timely prediction of a hazardous event can save human lives but does little to reduce economic losses or social disruption; that can only be accomplished by measures taken longer in advance. Included in the concept of disaster mitigation is the basic assumption that the impact of disasters can be avoided or reduced when they have been anticipated during development planning. Mitigation of disasters usually entails reducing the vulnerability of the elements at risk, modifying the hazard-proneness of the site, or changing its function. Mitigation measures can have a structural character, such as the inclusion of specific safety or vulnerability reduction measures in the design and construction of new facilities, the retrofitting of existing facilities, or the building of protective devices. Non-structural mitigation measures typically concentrate on limiting land uses, use of tax incentives and eminent domain, and risk underwriting through insurance programs.

Many countries are making efforts to introduce mitigation measures in hazard-prone areas. For example, the coastal area of Ecuador and the northern area of Peru are often affected by severe floods caused by "El Niño" or the El Niño Southern Oscillation (ENSO) phenomenon, which recurs approximately every 3 to 16 years. Between November 1982 and June 1983, heavy rains created the most dramatic series of floods reported this century, affecting 12,000 square kilometers in this region, with total losses estimated at US$1,200 million. Subsequently, Peru transferred six of the most affected villages to higher elevations (a non-structural mitigation measure), and introduced special adobe-building techniques to strengthen new constructions against earthquakes and floods (a structural mitigation measure).

Disaster mitigation also includes the data collection and analysis required to identify and evaluate appropriate measures and include them in development planning. The data collection involves essentially three kinds of studies:

Natural Hazard Assessments

Studies that assess hazards provide information on the probable location and severity of dangerous natural phenomena and the likelihood of their occurring within a specific time period in a given area. These studies rely heavily on available scientific information, including geologic, geomorphic, and soil maps; climate and hydrological data; and topographic maps, aerial photographs, and satellite imagery. Historical information, both written reports and oral accounts from long-term residents, also helps characterize potential hazardous events. Ideally, a natural hazard assessment promotes an awareness of the issue in a developing region, evaluates the threat of natural hazards, identifies the additional information needed for a definitive evoluation, and recommends appropriate means of obtaining it.

Vulnerability Assessments

Vulnerability studies estimate the degree of loss or damage that would result from the occurrence of a natural phenomenon of given severity. The elements analyzed include human population/capital facilities and resources such as settlements, lifelines, production facilities, public assembly facilities, and cultural patrimony; and economic activities and the normal functioning of settlements. Vulnerability can be estimated for selected geographic areas, e.g., areas with the greatest development potential or already developed areas in hazardous zones. The techniques employed include lifeline (or critical facilities) mapping and sectoral vulnerability analyses for sectors such as energy, transport, agriculture, tourism, and housing. In Latin America and the Caribbean vulnerability to natural hazards is rarely considered in evaluating an investment even though vulnerability to other risks, such as fluctuating market prices and raw-material costs, is taken into account as standard practice.

Risk Assessments

Information from the analysis of an area's hazards and its vulnerability to them is integrated in an analysis of risk, which is an estimate of the probability of expected loss for a given hazardous event. Formal risk analyses are time-consuming and costly, but shortcut methods are available which give adequate results for project evaluation. Once risks are assessed, planners have the basis for incorporating mitigation measures into the design of investment projects and for comparing project versus no-project costs and benefits.

b. Natural Hazard Prediction

Even short notice of the probable occurrence and effects of a natural phenomenon is of great importance in reducing loss of life and property. The prediction of a natural event is a direct outcome of scientific investigation into its causes and is aimed at establishing the probability of the next occurrence in terms of time, place, and range of severity. Increasingly sophisticated monitoring stations, both manned and remote, collect information of potentially hazardous events for more accurate prediction.

Some hazards, such as hurricanes and floods, can be forecast with high accuracy, but most geologic events cannot. Alert systems for some kinds of disasters suffer from a very short lead time. In the case of tsunamis, for example, the Pacific Warning Center, which constantly monitors the oceans, provides advance notice that varies from ten minutes to a few hours. At best, these warnings provide enough time to withdraw the population, but not to take other preventive measures.


Human Settlements:

Human population and associated housing and services.

Critical Facilities:

(1) Essential services, such as telecommunications, water, energy, and sanitation; (2) emergency medical services, fire and police stations, and disaster organizations; and (3) local, national, and international transportation facilities and carriers.

Economic Production Facilities:

Major sources of livelihood of the population, such as industries, banking and commerce buildings, public markets, agroprocessing plants and areas of agricultural production, livestock, forestry, mines, and fisheries production.

Public Assembly Sites:

Buildings such as schools, churches, auditoriums, theatres, public markets, and public and private office buildings.

Cultural Patrimony:

Buildings of significant cultural and community value or use, and buildings of architectural importance.

Although world-wide efforts to anticipate earthquakes persist, their prediction is still an incipient science. Few forewarnings have been as successful as the one made in February 1975 when the people of Haicheng, China, were evacuated six hours before a magnitude M.7 earthquake struck. Other predictions have been disastrous, as was the case with the erroneous warning of an imminent earthquake in Peru in 1981. Thousands of people fled, causing some deaths and long-term disruption of investment and tourism.

c. Emergency Preparedness

Emergency preparedness is aimed at minimizing the loss of life and property during a natural event. Preparedness includes actions taken in anticipation of the event and special activities both during and immediately after the event.

Two levels of preparedness can be identified: public safety information and hazard awareness planning. The first includes a number of efforts aimed at increasing the amount of information disseminated to the public and at promoting cooperation between the public and the authorities in case of an emergency. In the course of an event, or in its aftermath, social and public behavior undergoes important changes. This results in new organizational responsibilities for the public sector. Hazard information and education programs can improve public preparedness and social conduct during a disaster.

Hazard awareness planning is concerned about improving the ability of a particular area, region, or nation to respond to natural disasters. Disaster preparedness promotes the development of a system for monitoring known hazards, a warning system, emergency and evacuation plans, emergency routes, and the formulation of educational programs for public officials and professionals. Many Latin America and Caribbean countries are developing and adopting emergency plans in order to identify and effectively mobilize human and national resources in case of a disaster.

d. Disaster Rescue and Relief

After a natural calamity, local residents usually undertake the first relief activities. However, their efforts must usually be complemented with those of national or regional authorities. The keystones of post-disaster relief are the preparation of lifelines or critical facilities for emergency response, training, disaster rehearsals, and the identification and allocation of local and external resources.

Relief activities are affected by broad-scale planning decisions, but they are not a part of the mainstream national and regional planning processes. Although relief and disaster preparedness receive the most resources at the international, national, regional, and local levels, cost-effective mitigation measures are not adequately considered. This lack of forethought exacerbates the effects of natural disasters in terms of loss of life and property. Meanwhile, natural disasters continue to occur worldwide, and the number of people affected is increasing faster than the population growth rate.

e. Post-Disaster Rehabilitation and Reconstruction

Concurrent with or immediately after relief activities, post-disaster rehabilitation is carried out to restore the normal functions of public services, business, and commerce, to repair housing and other structures, and to return production facilities to operation. However, mitigation is often ignored in this phase: rehabilitation proceeds without any measures to reduce the chances of the same impact if the event happens again. In developing countries, road systems that are flooded or blocked by landslides year after year are commonly rebuilt at the same site and with similar design specifications.

In considering reconstruction costs, existing development policies and sectoral projects need to be reevaluated. In many cases, they are no longer appropriate or do not coincide with the best use of natural resources. For this reason, the natural hazard management process must examine any changes in the resources, goals, objectives, and products of development plans and incorporate these factors into subsequent planning activities.

f. Education and Training Activities

Education and training, both formal and informal, prepare people at all levels to participate in hazard management. Universities, research centers, and international development assistance agencies play the leading formal role in preparing individuals in a variety of skill levels such as natural hazards assessment, risk reduction, and natural phenomena prediction. These activities are also carried out by operational entities such as ministries of agriculture, transportation, public works, and defense.

Informal learning can be delivered through brochures, booklets, and audio and video tapes prepared by national and international agencies involved in disaster preparedness and mitigation programs, and through the national media. Additionally, courses, workshops, conferences, and seminars organized by national and international disaster assistance agencies disseminate great amounts of information on natural hazard management strategies.

Finally, direct observation after a disaster has proved to be one of the most effective means of learning. Post-disaster investigations describe the qualitative and quantitative aspects of natural hazards, often improving on information produced by modelling and conjecture by indicating areas where development should be extremely limited or should not take place. A direct outcome of the learning process is (1) the improvement of policies and program actions, building codes, standards, construction and design skills; (2) the development of legislation to mandate the adoption of these policies and the strengthening or creation of new disaster organizations; (3) the improvement of the key logistical aspects of disaster prevention, such as communication and warning systems; and (4) the establishment of community and resource organizations to confront future disasters.

2. Incorporating Mitigation Measures into the Stages of an Integrated Development Planning Study

a. Preliminary Mission: Designing the Study
b. Phase I: Development Diagnosis
c. Phase II: Project Formulation and Action Plan Preparation
d. Implementing the Study Recommendations

Integrated development planning is a multidisciplinary, multisectoral approach to planning.

Issues in the relevant economic and social sectors are brought together and analyzed vis-a-vis the needs of the population and the problems and opportunities of the associated natural resource base. A key element of this process is the generation of investment projects, defined as an investment of capital to create assets capable of generating a stream of benefits over time. A project may be independent or part of a package of projects comprising an integrated development effort. The process of generating projects is called the project cycle. This process proceeds from the establishment of development policies and strategies, the identification of project ideas, and the preparation of project profiles through prefeasibility and feasibility analyses (and, for large projects, design studies) to final project approval, financing, implementation, and operation.

While the process is more or less standardized, each agency develops its own version. The development planning process evolved by the OAS/DRDE consists of four stages: Preliminary Mission, Phase I (development diagnosis), Phase II (project formulation and preparation of an action plan), and Implementation. Because the process is cyclical, activities relating to more than one stage can take place at the same time. The main elements of the process are shown in Figure 1-2, and a synthesis of the activities and products of each stage is shown in Figure 1-3. A comprehensive set of guidelines for executing a study following this process is given in Regional Development Planning: Guidelines and Case Studies from OAS Experience.

Figure 1-2 - Key elements in the process of OAS assistance for integrated regional development planning

Source: OAS. Integrated Regional Development Planning: Guidelines and Case Studies from OAS Experience (Washington, O.C.: OAS, 1984).

Figure 1-3 - Synthesis of the OAS integrated development planning process








Development Diagnosis

Project Formulation and Preparation of Action Plan


Receipt and analysis of request for cooperation

Diagnosis of the region

Project formulation (pre-feasibility or feasibility) and evaluation

Assistance for specific programs and projects

- sectoral analysis

- production sectors (agriculture, forestry, agroindustry, industry, fishing, mining)

Assistance in incorporating proposed investments into the national budget

- spatial analysis

- support services (marketing, credit, extension)

Advisory services for private sector actions

Preliminary Mission

- institutional analysis

- social development (housing, education, labor training, health)

Support to executing agencies

- pre-diagnosis

- environmental analysis

- infrastructure (energy, transportation, communications)

Support in the inter- institutional coordination

- cooperation agreement preparation

- synthesis: needs, problems, potentials, constraints

- urban services

Relation to national plans, strategies and priorities

- natural resource management

Development strategies

- formulation and analysis of alternatives

Action plan preparation

- identification of project ideas, preparation of project profiles

- formulation of project packages

- determination of policies for priority areas and sectors

- enabling and incentive actions

- investment timetable

- evaluation of funding sources

- institutional development and training

- promotion


Signed agreement

Interim Report (Phase I)

Final Report

Execution by government of

- definition of the study products

- diagnosis of the region

- development strategy

- final design studies

- financial commitments of participants

- preliminary development strategy

- action plan

- project implementation

- preliminary workplan

- identified projects

- formulated projects

- changes in legislation and regulations

- supporting actions

Improved operational capability of institutions

Time Frame:

3 to 6 months

9 to 12 months

12 to 18 months


This presentation of the procedures of an integrated study features the incorporation of hazard management considerations at each stage. The relationships of the integrated development planning process, the hazard management process, and the project cycle are summarized in Figure 1-4.

Generally, planners depend on the science and engineering community to provide the required information for natural hazard assessments. If the information available is adequate, the planner may decide to make an assessment. If it is not adequate, the planner usually decides that the time and cost of generating more would be excessive, and the assessment is not made. While the information available on hurricanes and geologic hazards is often adequate for a preliminary evaluation, the information on desertification, flooding, and landslide hazards rarely is. The OAS has developed fast, low-cost methodologies that make these evaluations possible in the context of a development study. The differences in treating the various hazards in each stage of the process are highlighted in the following discussion.

a. Preliminary Mission: Designing the Study

The first step in the process of technical assistance for an integrated development planning study is to send a "preliminary mission" to consult with officials in the interested country. Experience has shown that this joint effort of OAS staff and local planners and decision-makers is frequently the most critical event in the entire study. They take action to:

- Determine whether the study area is affected by one or more natural hazards. For example, the National Environmental Study of Uruguay conducted by the OAS with financial support from the Inter-American Development Bank determined in the preliminary mission that natural hazards were an important environmental problem, and consequently an assessment of all significant hazards, to be conducted by reviewing existing information, was programmed for Phase I.

- Identify the information available for judging the threat posed by those hazards in the study area: history of hazardous events; disaster and damage reports; assessments of hazards, vulnerability, risk; maps and reports on natural resources and hazards; topographic maps, aerial photographs, satellite imagery.

- Determine whether the available data are sufficient to evaluate the threat of hazards. If they are not, determine what additional data collection, hazard assessment, remote sensing, or specialized equipment will be needed for the next stage of the study. For example, in preliminary missions in Dominica, Saint Lucia, and St. Vincent and the Grenadines, landslides were determined to be a serious problem, and landslide assessments were included in the work plan for Phase I.

- Determine whether the studies required would serve more than one sector or project. If so, establish coordination.

- Establish coordination with the national institution responsible for disaster planning.

- Prepare an integrated work plan for Phase I that specifies the hazard work to be done, the expertise needed, and the time and cost requirements.



- Is there a history of significant natural hazards in the study area?

- What is the likelihood of occurrence of natural hazard phenomena during the time frame of the development project?

- If hazards pose a threat, what is their expected severity, frequency, and the demarcation of the affected zone?


- Natural hazards are (or are not) a threat in the study area and therefore consideration of hazards should (or should not) be included in the development planning process.

- Natural hazards identified in the study should be considered in the definition and design of the planning framework, spatial context, study goals, and project procedures management.

- The workplan should include the financial and personnel resources needed for obtaining the appropriate hazard information in the various stages of project design and formulation.

- If natural hazard phenomena are found to constitute a significant threat to the study area, mitigation efforts should be built into the study design or alternatives to development should be proposed.

- If the information available is insufficient for a recommendation on the above decisions in the Preliminary Mission, Phase I should include the necessary data collection effort so that appropriate recommendations can be made.

Figure 1-4 - Integrated development planning process, natural hazard management, and the project cycle



- Is the project area vulnerable to natural hazards? Which ones?

- Do natural hazards currently constitute a significant constraint in determining a development strategy and identifying projects?

- Are modifications in the project study needed at this stage? Which ones?


- Can non-structural mitigation measures be included as part of the development strategy? Which ones?

- Is it likely that structural mitigation measures will have to be considered?

- What mechanism will be used to incorporate the vulnerability assessment information into the overall study activities?

- Would mitigation measures hinder project implementation? What is the social cost of a decision of this nature? How can such an outcome be avoided?

How and by whom can the assessment information be summarized for project formulation and action plan preparation?

- Is more information on hazardous events and critical facilities in the project area needed for the next stage of project formulation? How will this information be collected?

- Should the design of the planning framework, spatial context, and management structure be reevaluated and mitigation strategies incorporated into project formulation and action plans?

b. Phase I: Development Diagnosis

In Phase I, the team analyzes the study region and arrives at detailed estimates of development potentials and problems of the region and selected target areas. From this analysis a multisectoral development strategy and a set of project profiles are prepared for review by government decision-makers. Phase I also includes a detailed assessment of natural hazards and the elements at risk in highly vulnerable areas which facilitates the early introduction of non-structural mitigation measures. During this phase the team will:

- Prepare a base map.

- Determine the goods, services, and hazards of the region's ecosystems. Identify cause-and-effect relationships between natural events and between natural events and human activity. In the hilly Chixoy region of Guatemala, for example, it was found that inappropriate road construction methods were causing landslides and that landslides, in turn, were the main problem of road maintenance. In Ecuador, the discovery that most of the infrastructure planned for the Manabí Water Development Project was located in one of the country's most active earthquake zones prompted a major reorientation of the project.

- Evaluate socioeconomic conditions and institutional capacity. Determine the important linkages between the study region and neighboring regions.

- Delineate target areas of high development potential, followed by more detailed natural resource and socioeconomic studies of these areas.

- In planning the development of multinational river basins or border areas where a natural disaster could precipitate an international dispute, make an overall hazard assessment as part of the resource evaluation. Examples of such studies include those for the development of the San Miguel-Putumayo River Basin, conducted in support of the Colombia-Ecuador Joint Commission of the Amazon Cooperation Project, and for the Dominican Republic and Haiti Frontier Development Projects.

- Conduct assessments of natural hazards determined to be a significant threat in the study region. For hurricanes and geologic hazards, the existing information will probably suffice; if the information on geologic hazards is inadequate, an outside agency should be asked to conduct an analysis. For flooding, landslides, and desertification, the planning team itself should be able to supplement the existing information and prepare analyses. The studies of the Honduran departments of Atlántida and Islas de la Bahía included flood hazard assessment as part of the coastal area development plan and landslide hazard assessments for some of the inland areas.

- Conduct vulnerability studies for specific hazards and economic sectors. Prepare lifeline maps, hazard zoning studies, and multiple hazard maps as required. The study of the vulnerability of the Ecuadorian agriculture sector to natural hazards and of ways to reduce the vulnerability of lifelines in St. Kitts and Nevis, for example, both generated project ideas which could be studied at the prefeasibility level in Phase II. The study of the Paraguayan Chaco included flood and desertification assessments and multiple-hazard zoning. The execution of these hazard-related activities did not distort the time or cost of the development diagnosis.

- Identify hazard-prone areas where intensive use should be avoided.

- Prepare a development strategy, including non-structural mitigation measures as appropriate.

- Identify project ideas and prepare project profiles that address the problems and opportunities and that are compatible with political, economic, and institutional constraints and with the resources and time frame of the study.

- Identify structural mitigation measures that should be incorporated into existing facilities and proposed projects.

- Prepare an integrated work plan for the next stage that includes hazard considerations.

c. Phase II: Project Formulation and Action Plan Preparation

At the end of Phase I a development strategy and a set of project profiles are submitted to the government. Phase II begins after the government decides which projects merit further study. The team now makes prefeasibility and feasibility analyses of the projects selected. Refined estimates are made of benefits (income stream, increases in production, generation of employment, etc.) and costs (construction, operation and maintenance, depletion of resources, pollution effects, etc.). Valuative criteria are applied, including net present value, internal rate of return, cost-benefit ratio, and repayment possibilities. Finally, the team assembles packages of investment projects for priority areas and prepares an action plan. More detail on this phase is given in the section on Hazard Mitigation Strategies for Development Projects, but broadly speaking the team must:

- Examine the human activities that could contribute to natural hazards (e.g., irrigation, plowing in the dry season, and animal husbandry could cause or exacerbate desertification) and the social and cultural factors that could influence project vulnerability during and after implementation.

- Determine the levels of technology, credit, knowledge, information, marketing, etc., that it is realistic to expect will be available to the users of the land, and ensure that the projects formulated are based on these levels.

- Prepare site-specific vulnerability and risk assessments and appropriate vulnerability reduction measures for all projects being formulated. For example, the multimillion-dollar program for the development of the metropolitan area of Tegucigalpa, Honduras, featured landslide mitigation components. Flood alert and control projects were central elements in the comprehensive Water Resource Management and Flood Disaster Reconstruction Project for Alagoas, Brazil.

- Mitigate the undesirable effects of the projects, avoid development in susceptible areas, recommend adjustments to existing land use and restrictions for future land use.

- Examine carefully the compatibility of all projects and proposals.

- Define the specific instruments of policy and management required for the implementation of the overall strategy and the individual projects; design appropriate monitoring programs.



- To what degree do hazards pose a significant risk to existing or proposed development projects?

- Is the information resulting from Phase I sufficient to proceed with investment project formulation? If not, will additional assessment activities take place within or outside of the planning study?

- Which areas should be included in any additional assessment?


- Who will be responsible for incorporating additional information in project formulation activities?

- Are there certain non-structural mitigation measures that should be included in the formulation of investment projects, such as regulation of land use, warning systems, and the creation of hazard-oriented organizations?

- Should structural mitigation measures be considered as part of project investment? How much would they cost? Are they economically, socially, and politically feasible? Who will carry out the mitigation measures identified in the project? How and by whom will risk information be incorporated into study documents?

- What complementary activities should the study team carry out to maximize the use of the hazard assessment and mitigation information by potential funders and disaster-oriented institutions?

d. Implementing the Study Recommendations

The fourth stage of the development planning process helps implement the proposals by preparing the institutional, financial, and technical mechanisms necessary for successful execution and operation. Efforts made to consider hazards in previous stages will be lost unless mitigation measures are closely adhered to during the projects' execution. Either the planning agency or the implementing agency should:

- Ensure that suitable hazard management mechanisms have been included in all investment projects; provide for monitoring of construction to insure compliance with regulations, and for ongoing monitoring to ensure long-term compliance with project design.

- Ensure that national disaster management organizations have access to the information generated by the study. Point out hazardous situations for which the study did not propose vulnerability reduction measures.

- Arrange for the continuing collection of hazard data and the updating of information of planning and emergency preparedness agencies.

- Prepare legislation mandating zoning codes and restrictions, building and grading regulations, and any other legal mechanisms required.

- Include adequate financing for hazard mitigation measures.

- Involve the private sector in the vulnerability reduction program.

- For community-based vulnerability reduction programs, establish national training and hazard awareness programs for town and village residents, a feature of OAS technical assistance programs for Saint Lucia and Grenada.

- Generate broad-based political support through the media, training programs, and contacts with community organizations. Use products of the studies (photos, maps, charts, etc.) for mass communication. Use personnel who participated in the studies in public meetings to promote the concept of vulnerability reduction.

- Accelerate the implementation of projects that include hazard mitigation considerations; if budget cutbacks occur, reduce the number of projects rather than dropping the hazard mitigation components.



- How are mitigation and risk information be used in project funding approval and implementation activities?


- How and by whom will mitigation and risk information be integrated into the project funding and implementation of activities?

- Which institutions are responsible for the update, control, and dissemination of new and existing information?

3. Advantages of Integrated Development Planning for Natural Hazard Management

Even though integrated development planning and hazard management are usually treated in Latin America and the Caribbean as parallel processes that intermix little with each other, it is clear that they should be able to operate more effectively in coordination, since their goals are the same-the protection of investment and improved human well-being-and they deal with similar units of space. Some of the advantages of such coordination are the following:

- There is a greater possibility that vulnerability reduction measures will be implemented if they are part of a development package. The possibility increases if they are part of specific development projects rather than stand-alone disaster mitigation proposals. Furthermore, including vulnerability reduction components in a development project can improve the cost-benefit of the overall project if risk considerations are included in the evaluation. A dramatic example is the case study on vulnerability reduction for the energy sector in Costa Rica.

- Joint activities will result in a more efficient generation and use of data. For example, geographic information systems created for hazard management purposes can serve more general planning needs.

- The cost of vulnerability reduction is less when it is a feature of the original project formulation than when it is incorporated later as a modification of the project or an "add-on" in response to a "hazard impact analysis." It is even more costly when it is treated as a separate "hazard project," independent of the original development project, because of the duplication in personnel, information, and equipment.

- Exchanging information between planning and emergency preparedness agencies strengthens the work of the former and alerts the latter to elements whose vulnerability will not be reduced by the proposed development activities. In the Jamaica study of the vulnerability of the tourism sector to natural hazards, for example, solutions were proposed for most of the problems identified, but no economically viable solutions were found for others. The industry and the national emergency preparedness agency were so warned.

- With its comprehensive view of data needs and availability, the planning community can help set the research agenda of the science and engineering community. For example, when a planning team determines that a volcano with short-term periodicity located close to a population center is not being monitored, it can recommend a change in the priorities of the agency responsible.

- Incorporating vulnerability reduction into development projects builds in resiliency for the segment of the population least able to demand vulnerability reduction as an independent activity. A clear example of this situation was the landslide mitigation components of the metropolitan Tegucigalpa study: the principal beneficiaries were the thousands of the city's poor living in the most hazard-prone areas.


1. Energy in Costa Rica
2. Tourism in Jamaica
3. Agriculture in Ecuador
4. Strategies Derived from the Case Studies

The managers of public and private sectoral agencies share a concern about the vulnerability of their sectors to hazardous events: What hazards threaten which services? Where are the weak links? How much damage might be done? How would the damage affect sector investment, income, employment, and foreign currency earnings? What is the impact of losing x service in y city for z days? What investment in mitigation would resolve that problem? What is the cost/benefit of that investment? In the experience of the OAS the sectors that can benefit most from vulnerability assessments are energy, transport, tourism, and agriculture, since these sectors typify problems of disaster impact faced by developing countries.

Presented below are case studies of hazard assessments for the energy sector, the tourism sector, and the agriculture sector. The section ends with some strategies for conducting such assessments for selected economic sectors.

1. Energy in Costa Rica

In 1989 the Costa Rican Sectoral Directorate of Energy asked the OAS to assist in analyzing the vulnerability of the energy sector to natural hazards. The study first defined the nature of possible impacts. These included:

- Loss of infrastructure; associated investment losses
- Loss of income to the sector from forgone energy sales
- Effect on the production of goods and services; associated losses of employment income
- Loss of foreign exchange
- Negative impact on the quality of life

It was clear that the study would have to cover not only the energy subsectors, but also the service and economic sectors that could affect or be affected by energy supply. Thus it included the electric power system, the hydrocarbon system, railroads, roads, telecommunications, the metropolitan aqueduct, and the major economic production sectors. Existing information was analyzed for earthquakes, volcanic eruptions, landslides, hurricanes, flooding, drought, and erosion.

To evaluate the vulnerability of each facility, the study used two methods simultaneously: field examination and the preparation of a geographic information system which could overlay each hazard with each energy and service system. Figure 1-5 shows one of the CIS overlays: landslide threats to transmission lines. Matrices prepared to show impacts were rated as follows:

- No impact
- Potential threat, major or minor
- Confirmed threat, major or minor

A rapid examination of the threats yielded a number of serious problems. The confirmed major impacts caused by each hazard in each sector are shown in Figure 1-6. The most important problems were studied in greater detail and actions to deal with them were recommended. Some examples follow.

- The worst event would be a strong earthquake or volcanic eruption that breached Arenal dam or crippled the Arenal and Corobici hydroelectric plants, cutting off half of the hydropower in the country. The probability of such an event is low, but the magnitude of the catastrophe is so great it has to be planned for. The report recommended contingency plans for emergency generation and the establishment of new power plants outside the Arenal system.

- Two critical substations and two transmission lines are threatened by earthquakes, landslides, volcanic eruptions, flooding, and severe windstorms. The multiple hazards make the probability of occurrence moderate, and the loss of any of these components would cut off power from the Arenal system to the central region. The report recommended building an alternate transmission line that would bypass the four components.

- Landslides periodically damage one segment of the railroad that carries heavy petroleum derivatives from the refinery on the Atlantic Coast to a critical substation in San Jose. Since having the substation out of commission for a long time would be a major catastrophe for the region and rerouting the railroad would be too expensive, the report recommended equipping a West Coast port with facilities for handling a substitute supply which could be trucked to San Jose.

Figure 1-5 COSTA RICA: Energy sector vulnerability to landslide hazardz

Source: Adapted from Departamento de Desarrollo Regional/Organización de los Estados Americanos (OEA) and Dirección Sectorial de Energía/Ministerio de Recursos Naturales, Energía y Minas de Costa Rica (MIRENEM). Amenazas Naturales y la Infraestructura Energética de Costa Rica (San Jose, Costa Rica: unpublished report, 1989).


Electric Power Subsector

Oil and Gas Subsector a/



Hydropower plants

Thermal plants

Transmission lines















Landslides b/




























River flooding


















a/ No confirmed major impacts on port or substations
b/ Caused by earthquakes, volcanic eruptions, flooding, hurricanes

Source: Adapted from Departamento de Desarrollo Regional/Organización de los Estados Americanos (OEA) and Dirección Sectorial de Energía/Ministerio de Recursos Naturales, Energía y Minas de Costa Rica (MIRENEM). Amenazas Naturales y la Infraestructura Energética de Costa Rica. (San José, Costa Rica: unpublished report, 1989).

The Government found the recommendations valid and is now seeking financing for feasibility studies of the most critical ones. It is noteworthy that so many serious problems could be identified in a three-month study and, more importantly, that many were amenable to mitigation by relatively modest investments.

2. Tourism in Jamaica

The geographic and climatic setting of the Caribbean and the siting of tourism projects on or near the beaches combine to make Caribbean tourism especially vulnerable to disruption from natural disasters. In the island countries hurricanes are the most damaging hazard, but land-based flooding, landslides, earthquakes, and wildfires also exact a toll.

Direct damage caused by Hurricane Gilbert to property and equipment of the tourism industry amounted about US$85 million. The indirect damage was much greater. In foreign exchange alone the cost from September to December 1988 was US$90 million - a particularly painful loss since the foreign exchange was needed to finance recovery programs. The temporary closing of hotels for repairs meant fewer visitors to the island, causing other indirect effects such as loss of income for the national airline and reduction in employment and the purchase of local goods and services.

The vulnerability of the tourism industry is not confined to its own capital stock, as was demonstrated by the Jamaican experience. Damage to roads, utilities, airports, harbors, and shopping centers also affected the industry. Conscious of the need to minimize damage from future events, the Government of Jamaica requested OAS technical cooperation in preparing an assessment of the vulnerability of the tourism sector to natural hazards and recommending mitigation actions.

The assessment disclosed that much of the damage to tourism facilities, as to other buildings, was due to lack of attention to detail in construction and maintenance, particularly in roof construction. Roof sheeting was poorly interlocked. Tie-downs of roof structures were inadequate. Nail heads were rusted off. Timber strength was reduced by termites, and metal strength by corrosion. Much glass was needlessly blown out because of faulty installation and poor design criteria, but also because windows were not protected from flying debris. Drains clogged with debris caused excessive surface runoff, resulting in erosion and scouring around buildings. Local water shortages developed because the lack of back-up generators prevented pumping. Although a major contributor to the damage, faulty building practices and maintenance deficiencies are easy to correct: it was calculated that proper attention to these matters would have increased the cost of construction less than 1 percent.

Long-term mitigation measures were also identified. The study recommended the protection of beach vegetation, sand dunes, mangroves, and coral reefs, all of which help to protect the land from wave and wind action. New construction sites should be evaluated for susceptibility to hazards. Setback distance from the shore should be enforced, and the quality of sewage outfall should be maintained to protect live coral formations.

In short, the preliminary study, conducted in one month, identified a number of possible actions that would substantially reduce the impact of future hurricanes and other natural hazards. The preliminary analysis indicated that many of these actions would have a high cost-benefit ratio. Subsequently, Jamaica requested IDB financing to undertake feasibility analyses of these proposals and to implement them. The ultimate objective of this work is for the tourism sector to arrive at a "practical and effective loss reduction strategy and program in response to the risks posed by natural disasters to the industry."

3. Agriculture in Ecuador

In Ecuador, as in most Latin American and Caribbean countries, agriculture is one of the most important sources of income, employment, investments, and foreign exchange earnings. However, it is perhaps the most vulnerable and least protected sector in terms of infrastructure and institutional support to cope with natural hazards. In the floods caused by the El Niño phenomenon in 1982-83, for example, the agricultural sector suffered 48 percent of the US $232 million in damage. Furthermore, besides generating inflationary pressures on domestic prices, the disaster had a significant impact on the balance of payments due to the loss of export crops and the need to import basic food products to compensate for domestic production losses (ECLAC, 1983).

In 1990, the Ministry of Agriculture asked the OAS to assist in evaluating the vulnerability of the agricultural sector to natural hazards and identifying appropriate mitigation strategies to reduce it to acceptable levels. These strategies would be identified as project ideas or project profiles, some of which would be selected by local officials to be further studied and evaluated to determine their economic and technical viability.

The study, conducted at the national level, first defined 14 of the most important crops, grouped in three categories: basic food crops, strategic crops, and export crops. Key infrastructure support elements for the production, processing, storage, transportation, and distribution of agricultural products were also defined and geographically located. This information was overlaid in a geographic information system (GIS; see Chapter 5) with information on drought, erosion, floods, landslides, volcanic eruptions, and seismic hazards.

By relating province-level socioeconomic data to potential affected areas, the study was able to determine the impacts of natural events in terms of sectoral income, employment, investments, foreign exchange earnings, and national food security. On the basis of these criteria, 49 different situations were selected as the most critical. It was found, for example, that erosion hazards in Carchi Province would affect in the medium to long run 11,750 ha of the potato-growing area, which accounts for more than 43 percent of the national production and for 40 percent and 80 percent, respectively, of the employment and income produced by the sector in the province.

The most serious problems according to each of the five criteria were identified, and policy options that would achieve the best gains were established. It was determined, for example, that policies oriented to avoid unemployment should seek to mitigate flood hazards in Guayas Province and erosion hazards in Tungurahua Province. To protect foreign exchange earnings, the most effective actions would be to protect banana production in El Oro Province against drought hazards and to mitigate flood hazards in Guayas Province, especially in areas used for coffee and banana production.

Possible mitigation strategies were also identified as part of the study and planned or on-going programs and projects in the Ministry of Agriculture and other institutions were identified as suitable for carrying out some of these mitigation strategies and more detailed studies. A report describing the major findings and recommendations was prepared and submitted to the government for review. Based on these recommendations a US$317,000 technical cooperation proposal for hazard mitigation activities within the sector has been prepared by the Government and is to be presented to outside agencies for financing.

4. Strategies Derived from the Case Studies

The following observations are common to many sectors. Of course, many additional strategies apply to individual sector studies.

Sectors are useful units of analysis for examining hazard assessment and vulnerability reduction issues. Sectors are recognizable and legitimate program subjects. Banks make loans on the basis of sectors. A sectoral approach fits the organizational structure of both international finance agencies and national governments. The knowledge and experience of most technical professionals is built around a sectoral approach. Information for the development diagnosis (Phase I of an integrated development planning study) is collected and analyzed on a sectoral basis. Sectoral studies need not be restricted to economic sectors: urban and rural sectors and the poor also make valid units of study.

Vulnerability reduction measures can be cost-effective, either as stand-alone projects or. more commonly, as component elements of overall sector development programs. Including such measures can improve the cost-benefit ratio of investment projects.

Sector vulnerability studies are a new approach which can be considered for inclusion in development diagnosis (Phase I) studies. Initial national-level studies allow for a quick and low-cost assessment of policies and projects at a profile level that can be examined in greater detail later.

Sectoral studies reveal previously unrecognized linkages between disasters and development. Often a sector is unaware of its role in the lifeline or critical facilities network. In many cases it has no strategy for dealing with abnormal situations resulting from any exogenous event. The complex interrelationships among the components of some sectors make it difficult to cope with the impact of a natural event. This is particularly true when the sector is more concerned with one set of components, such as the production or generation of power, than with another set such as transmission, distribution, and storage. Furthermore, sectors usually do not have an adequate understanding of the effect a curtailment of service can have on other sectors.

A sector may have to select between competing objectives to arrive at a vulnerability reduction strategy. Criteria that define those competing objectives include investment in the sector, income stream, export earnings, employment, and sector security. The cost of a component may be disproportionate to the impact of its loss as measured by one of these criteria.


1. Technical Cooperation Agencies
2. Convincing Financing Agencies

1/This section is largely extracted from a previous OAS document, "Incorporating Natural Hazards Assessment and Mitigation into Project Preparation," published by the Committee of International Development Institutions on the Environment (CIDIE) in 1989.

The different categories of development assistance agencies (technical cooperation agencies, bilateral and multilateral lending agencies) each have a potential role in supporting the assessment and mitigation of natural hazards. Technical cooperation agencies such as the OAS support institution-building, research, planning, and project formulation as requested. Their financial impact and their political or technical leverage are limited. But their contribution to natural hazard assessment and mitigation in regional and sectoral planning, project identification, and prefeasibility studies is important.

Bilateral agencies such as AID, CIDA, and the members of the OECD Development Assistance Committee provide funds for projects as well as for technical cooperation. Most bilateral funds are concessional, and financial returns are less important to these agencies than to the development banks. They can exert considerable leverage over projects they fund.

The multilateral development banks, mainly the World Bank and the regional development banks, fund development projects but are also increasingly involved in sector policies, institutional strengthening, program lending, and structural adjustment. The dominant factors that shape their lending programs are the financial and economic soundness of an investment and the creditworthiness of the borrowing institutions. Within these parameters they can significantly influence hazard mitigation issues.

The conditions for increasing national and international attention to disaster mitigation issues may be stated as follows:

- The more developed a country's planning institutions and processes, the more easily natural hazards assessment and mitigation issues can be adopted.

- The more experience a country has gained in hazards assessment and mitigation issues can be adopted assessing specific hazards, often following a major disaster, the more likely it will be to request assistance for continuing such assessments.

- The more scientific, engineering, and prevention-related information available to countries and to donors, the easier it will be to apply natural hazards assessment and mitigation to individual programs and projects.

- The more experience governments and donors have concerning the kinds of mitigation measures that are most cost-effective and implementable, the less reluctant they are to include such measures in projects.

- The more experience and confidence there is in evaluating mitigation measures at various decision points in the project cycle, the more likely it is that the staffs of both the national and the assistance agencies will be prepared to undertake the analysis.

1. Technical Cooperation Agencies

For technical cooperation agencies such as the OAS, the activities that should be included in a strategy for promoting natural hazards assessment and mitigation are:

- Support for national planning institutions. Unless they have the institutional capacity to incorporate natural hazards information into the planning process on an inter-sectoral basis, governments are not likely to show any enthusiasm about looking at individual investment projects from this perspective.

- Support for pilot projects. By initiating natural hazards assessments on a pilot basis, it is possible to demonstrate how to do them and what mitigation measures can be proposed, and thereby generate further demand when governments request project funding from donors.

- Support for establishing an information base. Once the information necessary for natural hazard assessments is available, its implications for individual investment projects become difficult to ignore.

- Linkage with relief and reconstruction efforts. In the aftermath of disasters it is easier than it would otherwise be to interest governments and development assistance agencies in natural hazards assessment and mitigation.

- Hazards assessment in sector planning. By building natural hazards assessment into the planning of the agriculture, energy, housing, tourism, transportation, and other sectors, it should be possible to focus attention on hazards in relation to various types of projects before specific investments are identified.

- Inclusion of financial and economic aspects of hazards in project preparation methods. Estimating the benefits of avoiding direct losses from natural hazards and the costs of appropriate non-structural mitigation measures will make it easier to examine their true importance in individual investment projects. An awareness of the investment losses and repair costs to governments and the private sector, and the distribution of these costs and damages, is likely to increase sensitivity to the issue among all concerned.

- Case studies of project design principles or components aimed at natural hazard mitigation. Examples of relevant experiences-liability and insurance schemes for investments, property rights designed to create incentives for hazard mitigation, subsidies for mitigation measures, institutional responsibility for coordinating disaster relief with hazard assessment and mitigation, etc.-will show how funding activities can be made more responsive to natural hazards.

The OAS has initiated programs in all these activity areas though direct technical cooperation, training, applied research, and participation in international conferences and workshops. But the need for such activities is much greater than present resources allow. Financing agencies must also become more involved.

2. Convincing Financing Agencies

a. A Change in Context
b. Incentives for Analysis
c. Assignment of Accountability for Losses

A strategy to promote natural hazards assessment and mitigation must also find means of inducing the cooperation of the agencies that actually fund the investment projects. There are three elements that may offer this inducement: (1) a change in the context in which the donors perceive the governments and collaborating technical cooperation agencies to be addressing natural hazard assessment and mitigation issues; (2) incentives for analysis; and (3) the assignment of accountability for losses.

a. A Change in Context

Changing the context in which lending and donor agencies perceive natural hazard assessment and mitigation to be taking place includes most of the activities that the OAS is already promoting: assisting governments in regional planning, pilot natural hazards assessments, assistance for information systems, increasing the quality of project identification, and building the appropriate mitigation measures into pre-investment activities. Further development of these activities raises three strategic questions: What can be done that is most cost-effective in terms of improving both the commitment and the technical and institutional capacity for hazard assessment in a country? What outputs can be generated that are most likely to appeal to donors and therefore bridge the gap between hazard assessment and project preparation? What cooperative mechanisms can be developed between the technical assistance and donor agencies that will help reach the first two goals?

In response to the first question, implementation of the following ideas seems necessary:

- Focus on priority hazards. Efforts should be concentrated on assessing hazards that are sufficiently urgent to generate the necessary cooperation. Trade-offs must be made between the need for specific information and broad research interests.

- Focus on priority sectors. Losses in some sectors are likely to have greater immediate significance to governments and economic interests than in others, and it seems prudent to try to generate institutional support for attention to these.

- Choose simple and practical information collection and analysis systems. The burden of data collection and management often consumes all available technical and institutional capacity and resources, leaving none for decision-making and implementation. Information systems should reflect realistic priorities for hazards and the development activities that are affected.

As to the second question, the following guides should be used:

- Early identification and integration of mitigation issues. Mitigation measures built into projects from the earliest preparation stages are more likely to receive adequate review.

- Practical and cost-effective solutions to recurrent problems. For certain types of projects such solutions are less likely to be rejected if it can be shown that situations to which they are applicable are common.

- Commitment to implementation. Confidence in hazard mitigation is higher if governments appear committed to carrying it out.

As to the third question, the following ideas are suggested:

- Pooling of resources. Donor and technical assistance agencies should make their professional staff available for joint missions at varying stages of the project cycle.

- Exchange of experiences. Technical assistance agency representatives should periodically present case-study and other training material on the design and implementation of natural hazard assessment and mitigation techniques in project formulation taken from real field experiences. In turn, as their capability in this area improves, the donor agency staffs should present their policies, programs, and project evaluation criteria.

- Government institutional support. Natural hazard assessment and mitigation should be routinely included in staff development and training programs in conjunction with project formulation activities.

b. Incentives for Analysis

The project staff of a development financing agency will resist any requirement to incorporate natural hazards into project preparation and analysis unless it fits into the existing review mechanisms and appraisal methods. Various ways to promote this consistency exist:

- Provide reusable information. Agencies should set guidelines to alert their staffs to specific hazards, and give them examples of appropriate mitigation measures and implementation requirements. This approach depends on the institution of mechanisms to ensure that the guidelines are followed routinely.

- Integrate hazard concerns into existing review mechanisms such as programming missions, project identification reports, reconnaissance surveys, and project appraisal. Hazards will inevitably be one of many factors to be taken into account, and there is a danger that they will be overlooked if they are not made part of the standard format.

- Promote proven mitigation measures in relation to specific types of projects. Design standards, insurance schemes, diversification of crops, feasibility of hazard-resistant crops or designs are examples. Project staffs are more likely to become enthusiastic about positive project opportunities than about review mechanisms.

- Incorporate the costs and benefits of hazards mitigation into economic appraisal. This makes sense to the extent that decisions are made on the basis of economic returns, that the information on which to base the economic calculations is available, and that the analysis is geared towards improving project design. It is hard to generate support for a new activity unless it can be justified on the basis of financial and economic returns. From this point of view, it is an advantage to be able to show that hazard mitigation can save financial and economic costs in the conventional cost-benefit framework.

- Sensitize project staff members. This is especially important for project staff responsible for hazard-prone regions and sectoral advisers responsible for hazard-sensitive sectors. Training, cooperation, and publicity can contribute to making project staff more aware of the issue. This, probably more than any other factor, can offset the institutional and financial resistance to hazard assessment and mitigation on the part of governments and the development financing agencies alike.

c. Assignment of Accountability for Losses

The concern of development financing agencies for natural hazard assessment and mitigation depends on the degree to which projects they help plan or fund suffer losses from natural disasters. There are number of ways to assign accountability:

- Evaluate losses from natural hazards not only in the context of the creditworthiness of the government or a particular sector, but also of the donor's program area and its project design and loan repayment performance.

- Study, discuss, and publish evaluations in instances where losses have been incurred for projects that failed to consider or evaluate hazard mitigation measures.

- Promote professional standards on the part of the engineers, agronomists, or others responsible for planning and executing development projects that include natural hazards assessment and mitigation.


Bolt, B.A. Earthquakes (New York: W.H. Freeman and Company, 1988).

Burton, I., Kates, R.W., and White, G.F. The Environment as Hazard (New York: Oxford University Press, 1978).

ECLAC. Ecuador: Evaluation of the Effects of the 1982/83 Floods on Economic and Social Development (New York: ECLAC, 1983).

Hays, W.W. (ed.) Facing Geologic and Hydrologic Hazards. Earth-Science Considerations, Professional Paper 1240-B (Reston, Virginia: U.S. Geological Survey, 1981).

King, J. "In the Wake of the Quake" in Planning, December 1989 (Chicago, Illinois: APA, 1989).

Natsios, A.S. "Disaster Mitigation and Economic Incentives" in Colloquium on the Environment and Natural Disaster Management (Washington, D.C.: The World Bank, 1990).

Petak, W.J., and Atkisson, A.A. Natural Hazard Risk Assessment and Public Policy: Anticipating the Unexpected (New York: Springer-Verlag, 1982).

Previous PageTop of Page Next Page