The primary effects of hurricanes are that they are one of the most destructive natural hazards, both in terms of frequency and death toll. They pose a major threat to coastal areas, related to the storm surge threat. They are a multiple hazard, since loss of life and property can be a result of one of several factors; Heavy rain, High wind velocity, Storm surge, as a result of the above and low central pressure they also include secondary effects, Flooding, landslides, and related damage. Impacts are a function of when and where the hurricane hits. Storm Surges a storm surge is a large dome of water, 50-100miles wide, which sweeps across the coastline near where the hurricane makes landfall. It is water pushed towards the shore by the force of the winds swirling around the storm, and the drop in pressure (260mm sea level rise for a 30mb fall in pressure) The surge combines with the normal tide to create a storm tide, and wind waves are then superimposed upon this. It can be more than 15ft deep. Most of the US Atlantic and Gulf coasts lie less than 10ft above sea level; therefore at risk. The major danger is from flooding, particularly when coinciding with natural high tides. This causes great potential for loss of life. They not only damage structures, but the debris which they carry is dangerous too. External debris can become deadly missiles in the wind force. Damage to tall objects, esp. power lines, telephone cables can cause disruption. High rise buildings are at risk from windows blowing out, particularly at higher levels, since wind speed increases with height. Winds can stay above hurricane level well inland.
Comprehensive Emergency Management is the preparation for and the carrying out of all emergency functions, other than functions for which the military forces are primarily responsible, to mitigate, prepare for, respond to, and recover from emergencies and disasters, and to aid victims suffering from injury or damage, resulting from disasters caused by all hazards, whether natural, technological, or human caused, and to provide support for search and rescue operations for persons and property in distress (Wikipedia).
When you think of local or State Hazard mitigation plans we took New Orleans’s plan for hurricanes before Katrina. Mitigation includes those activities, policies or programs developed and adopted by government officials which will reduce, eliminate, or alleviate damage caused by disasters. Proper and coordinated planning is a prerequisite to effective and efficient procedural changes required in addressing hazard mitigation. The City of New Orleans currently participates in, or has commenced the initial stages of several programs intended to reduce the risk to lives and to minimize damage to public and private properties. Training and education on Disaster Preparedness are essential to local government and non-government disaster agencies, in order to mitigate the loss of life and property in the event of a peacetime emergency. An understanding of emergency operations, plus recurring education and training in emergency response and disaster operations, is the basis of response effectiveness. Individuals with assigned tasks must receive preparatory training to maximize operations. The goal of emergency preparedness training is the preparation of individuals and organizations for effective and coordinated response to emergencies. Under the direction of the Mayor, the Office of Emergency Preparedness will coordinate activities in accordance with the Comprehensive Emergency Management Plan to assure the coordination of training programs for all planning, support, and response agencies. Departments, authorities, agencies, municipalities, and all private response organizations bear the responsibility of ensuring their personnel are sufficiently trained (http://www.thehighroad.org).
Mitigation programs include coordinated city, state and federal efforts that are currently in place, such as the National Flood Insurance Program, or future actions designed to reduce the loss of life and extensive property damage. The City of New Orleans is a participant in the National Flood Insurance Program (NFIP). The City's participation is conducted by the City Planning Commission (CPC). Citizens may receive information as to the NFIP rating of their properties at the City Hall (CPC) office. As much of the development now in place in New Orleans was developed prior to adoption of NFIP standards and rating zones, it is anticipated that should a major hurricane strike our area that many structures, both private and public, would have to be rebuilt or replaced by structures meeting NFIP standards. Future mitigation plans include: drainage network management, protection of wetlands and marshes, floodplain management, preservation of the levee system, providing hurricane shelter, restricting imprudent development, mitigation actions following natural disasters, and post disaster plan development. In response to a major destructive storm, future plans call for the preparation of a post disaster plan that will identify programs and actions that will reduce or eliminate the exposure of human life and property to natural hazards. To direct the City's hurricane recovery operations, the Mayor will appoint a Recovery Task Force (RTF). The RTF shall include the Chief Administrative Officer, the Director of the Emergency Preparedness, Public Works Director, Public Utilities Director, Director of Safety and Permits and any others as directed by the Mayor. Staff shall be provided by those appointed, as well as by those elements of the OEP responsible for recovery operations. The RTF shall provide the following tasks: review and decide upon emergency building permits, analyze and recommend hazard mitigation options, including reconstruction or relocation of damaged public facilities; coordinate the preparation of the post disaster redevelopment plan; recommend amendments to the Comprehensive Emergency Management Plan, and other appropriate policies and procedures; coordinate with state and federal officials disaster assistance. In order to ensure broad based local participation in guiding long term redevelopment, the following recommendations are submitted: That the RTF be tasked with overseeing long term disaster recovery and mitigation efforts, once the life threatening aspects of a major disaster has passed, as an adjunct operation of the OEP; That the RTF shall develop periodic reports on recovery efforts and operations for submission to the Mayor and City Council; That the RTF focus on such issues as Building Code modifications, zoning and land use management, building code compliance and enforcement, retrofitting public facilities, local legislation designed to reduce the risk of life and property in areas vulnerable to the impacts of predictable, recurring hazards (http://www.thehighroad.org). The risk posed by hurricanes to a particular region is a function of the likelihood that a hurricane of certain intensity will strike it and of the vulnerability of the region to the impact of such a hurricane. Vulnerability is a complex concept, which has physical, social, economic and political dimensions. It includes such things as the ability of structures to withstand the forces of a hazardous event, the extent to which a community possesses the means to organize itself to prepare for and deal with emergencies, the extent to which a country's economy depends on a single product or service that is easily affected by the disaster, and the degree of centralization of public decision-making (Wilches-Chaux, 1989).
Population centers and economic activities in the region are highly vulnerable to disruption and damage from the effects of extreme weather. They are largely concentrated in coastal plains and low-lying areas subject to storm surges and land borne flooding. High demands placed on existing lifeline infrastructure, combined with inadequate funds for the expansion and maintenance of these vital systems, have increased their susceptibility to breakdowns. Uncontrolled growth in urban centers degrades the physical environment and its natural protective capabilities. Building sites safe from natural hazards, pollution, and accidents have become inaccessible to the urban poor, who are left to build their shelters on steep hillsides or in flood-prone areas (Bender, 1989). Communities, countries, or regions differ greatly in vulnerability, and hence in the effects they may suffer from hurricanes of similar strength. The very size of a country is a critical determinant of vulnerability: small island nations can be affected over their entire area, and major infrastructure and economic activities may be crippled by a single event. Scarce resources that were earmarked for development projects have to be diverted to relief and reconstruction, setting back economic growth. To assess future risks, planners must study historical trends and correlate them with probable future changes. The main cause of increasing vulnerability is the population movement to high-risk areas. Most cities in the West Indies are in low coastal zones threatened by storm surge (Tomblin, 1979), and they continue to grow.
The economic sectors most affected by hurricanes are agriculture and tourism. Together, these represent a major portion of the economy for the countries in the Caribbean. Particularly for island countries, agriculture is the most vulnerable activity (ECLAC/UNEP, 1979). Hurricanes have disastrous effects on banana crops in particular. During Hurricane Alien, in August of 1980, Saint Lucia suffered US$36.5 million in damage, with 97 percent of the banana plantations destroyed. In St. Vincent 95 percent, and in Dominica 75 percent, of the banana plantations were ruined (Earthscan No. 34a, 1983). Damage to the tourism industry is more difficult to quantify since it includes many other economically identifiable sectors such as transportation and hotel services.
Crop statistics rarely account for long-term losses. The increased salinity in the soil due to the storm surge can have detrimental effects on production in subsequent years. For example, Hurricane Fifi decreased production in Honduras by 20 percent the year it occurred, but in the following year production was down by 50 percent. How much of this reduction was due to the increase in salinity is unclear, but it is known that salt destroys vegetation slowly. Once the risk posed by hurricanes is understood, specific mitigation measures can be taken to reduce the risk to communities, infrastructure, and economic activities. Human and economic losses can be greatly reduced through well-organized efforts to implement appropriate preventive measures, in public awareness and in issuing timely warnings. Thanks to these measures, countries in the region have experienced a drastic reduction in the number of deaths caused by hurricanes.
Mitigation measures are most cost-effective when implemented as part of the original plan or construction of vulnerable structures. Typical examples are the application of building standards designed for hurricane-force winds, the avoidance of areas that can be affected by storm surge or flooding, and the planting of windbreaks to protect wind-sensitive crops. Retrofitting buildings or other projects to make them hurricane-resistant is more costly and sometimes impossible. Once a project is located in a flood-prone area, it may not be feasible to move it to safer ground.
The overall record on mitigation of hurricane risk in the Caribbean and Central America is not very encouraging. Cases abound of new investments in the public or productive sectors that were exposed to significant hazard risk because of inappropriate design or location, and even of projects that were rebuilt in the same way on the same site after having been destroyed a first time. Other cases can be cited of schools and hospitals funded with bilateral aid that were built to design standards suitable for the donor country but incapable of resisting hurricane-strength winds prevalent in the recipient country.
The tourism sector in the Caribbean is notorious for its apparent disregard of the risk of hurricanes and associated hazards. A hotel complex built with insufficient setback from the high-water mark not only risks being damaged by wave action and storm surge, but interferes with the normal processes of beach formation and dune stabilization, thus reducing the effectiveness of a natural system of protection against wave action. After the first serious damage is incurred the owners of the hotel will most likely decide to rebuild on the same site and invest in a seawall, rather than consider moving the structure to a recommended setback. Reduction of risk at the international level suggests that In the past three decades the technological capacity to monitor hurricanes has improved dramatically, and along with it the casualty rate has declined. New technology permits the identification of a tropical depression and on-time monitoring as the hurricane develops. The greatest advance has occurred in the United States, but developing countries benefit greatly because of the effective warning mechanism. The computer models also generate vast quantities of information useful for planners in developing nations.
Computer models that estimate tracking, landfall, and potential damage were first implemented in 1968 by the U.S. National Hurricane Center (NHC). At this point there are five operational track guidance models: Beta and Advection Model (BAM), Climatology and Persistance (CLIPER), a Statistical-dynamical model (NHC90), Quasi-Lagrangian model (QLM) and the barotropic VICBAR. They vary in capacity and methodology and occasionally result in conflicting predictions, though fewer than formerly. The NHC evaluates incoming data on all tropical storms and hurricanes in the Atlantic and eastern Pacific tropical cyclone basin and issues an official track and intensity forecast consisting of center positions and maximum one-minute wind speeds for 0, 12, 24, 48, and 72 hours.
The NHC has also developed a hurricane surge model named Sea, Lake and Overland Surges (SLOSH) to simulate the effects of hurricanes as they approach land. Its predecessor SPLASH, used in the 1960s, was useful for modeling hurricane effects along smooth coastlines, but SLOSH adds to this a capability to gauge flooding in inland areas. These results can be used in planning evacuation routes.
A computerized model that assesses the long-term vulnerability of coastal areas to tropical cyclones has also been developed. This model, the National Hurricane Center Risk Analysis Program (HURISK), uses historical information on 852 hurricanes since 1886. The file contains storm positions, maximum sustained winds, and central pressures (unavailable for early years) at six-hour intervals. When the user provides a location and the radius of interest, the model determines hurricane occurrences, dates, storm headings, maximum winds, and forward speeds. Vulnerability studies begin when the median occurrence date, direction distribution, distribution of maximum winds, probability of at least x number of hurricanes passing over n consecutive years, and gamma distribution of speeds are determined. Planners can use these objective return period calculations to evaluate an otherwise subjective situation. Reduction of risk at the national level implements One of the most important steps a country can take to mitigate the impact of hurricanes is to incorporate risk assessment and mitigation measure design into development planning. The design of basic mitigation measures begins with the compilation of all historical records of former hurricane activity in the country, to determine the frequency and severity of past occurrences. Reliable meteorological data for each event, ranging from technical studies to newspaper reports, should be gathered. With all the information in place, a study of (1) the distribution of occurrences for months of a year, (2) frequencies of wind strengths and direction, (3) frequencies of storm surges of various heights along different coastal sections, and (4) frequencies of river flooding and their spatial distribution should be undertaken. The statistical analysis should provide quantitative support for planning strategies.
The design of mitigation measures should follow the statistical analysis and consider long-term effects. Both non-structural and structural mitigation measures should be considered, taking into account the difficulties of implementation.
Non-structural measures consist of policies and development practices that are designed to avoid risk, such as land use guidelines, forecasting and warning, and public awareness and education. Much credit for the reduction of casualties from hurricanes in the Caribbean should be given to the Pan Caribbean Disaster Preparedness and Prevention Project (PCDPPP), which has worked effectively with national governments on motivating the population to take preventive measures, such as strengthening roof tie-downs, and on establishing forecasting and warning measures.
Structural mitigation measures include the development of building codes to control building design, methods, and materials. The construction of breakwaters, diversion channels, and storm surge gates and the establishment of tree lines are a few examples of mitigation from a public works standpoint.
Reduction of risk at the local level involves The effectiveness of national emergency preparedness offices of countries in the region is often seriously limited because of inadequate institutional support and a shortage of technical and financial resources. In the smaller Caribbean islands, these offices are mostly one-person operations, with the person in charge responsible for many other non-emergency matters. It would be unrealistic to expect them to be able to act effectively at the local level in cases of area-wide emergencies, such as those caused by hurricanes. It is therefore essential to enhance the capacity of the population in small towns and villages to prepare for and respond to emergencies by their own means. From 1986 through 1989, the OAS/Natural Hazards Project has worked with several Eastern Caribbean countries to evaluate the vulnerability of small towns and villages to natural hazards, and train local disaster managers and community leaders in organizing risk assessments and mitigation in their communities. These activities have resulted in the preparation of a training manual with accompanying video for use by local leaders. This effort has focused on lifeline networks-transportation, communications, water, electricity, sanitation-and critical facilities related to the welfare of the inhabitants, such as hospitals and health centers, schools, police and fire stations, community facilities, and emergency shelters. Mitigation Plans form the foundation for a community's long-term strategy to reduce disaster losses and break the cycle of disaster damage, reconstruction, and repeated damage. The planning process is as important as the plan itself. It creates a framework for risk-based decision making to reduce damages to lives, property, and the economy from future disasters. Hazard mitigation is sustained action taken to reduce or eliminate long-term risk to people and their property from hazards. This process has four steps: Step 1: From the start, communities should focus on the resources needed for a successful mitigation planning process. Essential steps include identifying and organizing interested members of the community as well as the technical expertise required during the planning process. Step 2: Next, communities need to identify the characteristics and potential consequences of hazards. It is important to understand how much of the community can be affected by specific hazards and what the impacts would be on important community assets. Step 3: Armed with an understanding of the risks posed by hazards, communities need to determine what their priorities should be and then look at possible ways to avoid or minimize the undesired effects. The result is a hazard mitigation plan and strategy for implementation. Step 4: Communities can bring the plan to life in a variety of ways, ranging from implementing specific mitigation projects to changes in day-to-day organizational operations. To ensure the success of an ongoing program, it is critical that the plan remains relevant. Thus, it is important to conduct periodic evaluations and make revisions as needed. (http://www.fema.gov/plan/mitplanning/overview.shtm) State, Indian Tribal, and local governments are required to develop a hazard mitigation plan as a condition for receiving certain types of non-emergency disaster assistance, including funding for mitigation projects. The Robert T. Stafford Disaster Relief and Emergency Assistance Act (Public Law 93-288), as amended by the Disaster Mitigation Act of 2000, provides the legal basis for State, local, and Indian Tribal governments to undertake a risk-based approach to reducing risks from natural hazards through mitigation planning. The requirements and procedures for State, Tribal and Local Mitigation Plans are found in the Code of Federal Regulations (CFR) at Title 44, Chapter 1, Part 201 (44 CFR Part 201). FEMA's Multi-Hazard Mitigation Planning Guidance is the official guidance for State, local, and Indian Tribal governments to meet the requirements of the Mitigation Planning regulations under the Stafford Act and 44 CFR Part 201. (http://www.fema.gov/plan/mitplanning/guidance.shtm)

References
1. Wilches-Chaux, G. Desastres, Ecologismo y Formación Profesional (Popayán, Colombia: Servicio Nacional de Aprendizaje, 1989).
2. Bender, S. "Disaster Prevention and Mitigation in Latin America and the Caribbean" in Colloquium on Disasters, Sustainability and Development: A Look to the 1990's. The Environment Department and the Human Resources Development Division of the World Bank (Washington, D.C.: The World Bank, 1989).
3. Tomblin, J. "Natural Disasters in the Caribbean: A Review of Hazards and Vulnerability" in Caribbean Disaster Preparedness Seminar, Saint Lucia, June, 1979 (Washington, D.C.: OFDA/USAID, 1979).
4. ECLAC/UNEP. Natural Disasters Overview. Meeting of Government-Nominated Experts to Review the Draft Action Plan for the Wider Caribbean Region, Caracas, Venezuela, 28 January -1 February, 1979 (Caracas: ECLAC/UNEP, 1979).
5. Earthscan Press Briefing Document no. 34a (Washington, D.C.: Earthscan Washington Bureau, 1983).
6. http://www.pupilvision.com/uppersixth/hurricanes.htm
7. Effect of Hurricane Katrina on New Orleans, April 2007 Wikipedia, URL: http://en.wikipedia.org/wiki/Effect of hurricane Katrina
8. City of New Orleans Comprehensive Emergency Management Plan
9. http://www.thehighroad.org