File Name: environmental hazards and disasters .zip
Losses due to natural hazards e. One response to hazard-related losses is migration, with this paper offering a review of research examining the association between migration and environmental hazards.
SUMMARY 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.
SUMMARY 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.
How Natural Are Natural Hazards? Environment, Natural Hazards and Sustainable Development 3. 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, 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 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.
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. 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. 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. 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 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. Rows and lateral spreads liquefaction phenomena are among the most destructive geologic hazards. Subsidence occurs in waterlogged soils, fill, alluvium, and other materials that are prone to settle. Volcanoes 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. 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. 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.
If the displacement occurs in surface material without total deformation it is called a slump. 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. 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. 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. 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, A study in the San Fernando Valley, California, after the earthquake showed that of 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 school buildings that met seismic-resistance standards suffered no structural damage Bolt, The Loma Prieta earthquake in was the costliest natural disaster in U. In the San Francisco Bay area post 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, 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. Flooding 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. Coastal flooding Storm surges are an abnormal rise in sea water level associated with hurricanes and other storms at sea.
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.
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.
By Raheem A. Usman, F. Olorunfemi, G. Awotayo, A. Tunde and B. Environmental Change and Sustainability. Disaster refers to an emergency caused by natural hazards or human-induced actions that results in a significant change in circumstances over a relatively short time period.
There are a range of environmental health hazards that affect our wellbeing. Hazards can be grouped together to improve understanding and action planning. The actions that you need to carry out to protect the health of your community depend on knowing how these hazards can affect us all. In this study session, you will learn about the types and categories of environmental health hazards, the routes of exposure and the ways of preventing and controlling these hazards. In Study Session 1, you learned that environmental health addresses the assessment and control of environmental factors that can potentially affect health.
The scientific community now stresses that both the underlying causes of human vulnerability to hazards, and the role of environmental conditions in exacerbating.
It seems that you're in Germany. We have a dedicated site for Germany. This book examines the aspects of prevention, mitigation, and management of environmental hazards and disasters from an international perspective. In light of the recent debate on climate change and the possible effects of such a change upon increasing frequency and magnitude of extreme environmental events, this publication overviews various policy and response discourse. Several case studies, from various countries and world regions, depicting recent experience in mitigation policy and program development and implementation and establishing interlinks between vulnerability and mitigation are presented to provide further insights.
Environmental health is defined as the control of those factors in the environment that may have deleterious effects on people's physical, mental, or social well-being. Because natural disasters expose people to danger by disrupting or threatening to disrupt their immediate environment, effective management of environmental health after a natural disaster is of primary importance.
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From the beginning of 21st century, there has been an awareness of risk in the environment along with a growing concern for the continuing potential damage caused by hazards. In order to ensure environmental sustainability, a better understanding of natural disasters and their impacts is essential. It has been recognized that a holistic and integrated approach to environmental hazards needs to be attempted using common methodologies, such as risk analysis, which involves risk management and risk assessment. Indeed, risk management means reducing the threats posed by known hazards, whereas at the same time accepting unmanageable risks and maximizing any related benefits. The risk management framework involves evaluating the importance of a risk, either quantitatively or qualitatively.
An environmental hazard is a substance, state or event which has the potential to threaten the surrounding natural environment or adversely affect people's health , including pollution and natural disasters such as storms and earthquakes. It can include any single or combination of toxic chemical, biological, or physical agents in the environment, resulting from human activities or natural processes, that may impact the health of exposed subjects, including pollutants such as heavy metals, pesticides, biological contaminants, toxic waste, industrial and home chemicals. Human-made hazards while not immediately health-threatening may turn out detrimental to a human's well-being eventually, because deterioration in the environment can produce secondary, unwanted negative effects on the human ecosphere. The effects of water pollution may not be immediately visible because of a sewage system that helps drain off toxic substances. If those substances turn out to be persistent e. In that respect, a considerable number of environmental hazards listed below are man-made anthropogenic hazards. Environmental hazard identification is the first step in environmental risk assessment , which is the process of assessing the likelihood, or risk , of adverse effects resulting from a given environmental stressor.
In this module, we will review disaster definitions, classifications, and measures reddingvwclub.org 30 environmental hazards.
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