Statement of Dr. Marc L. Levitan
Director, Louisiana State University – Hurricane Center,
Charles P. Siess, Jr. Associate Professor of Civil and Environmental
Louisiana State University and
President, American Association for Wind Engineering
On behalf of the LSU Hurricane Center
American Association for Wind Engineering
American Society of Civil Engineers
Wind Hazards Reduction Coalition
Before the Subcommittee on Disaster Prevention and Prediction
Committee on Commerce, Science and Transportation
United States Senate
Good morning and thank you for the opportunity to testify. I am Dr. Marc Levitan, I am the Director of the Louisiana State University Hurricane Center and the Charles P. Siess Professor of Civil and Environmental Engineering at Louisiana State University. I am also the elected President of the American Association for
Wind Engineering and a member of the American Society of Civil Engineers.
I am appearing today on behalf of the Louisiana State University Hurricane Center, the American Association for Wind Engineering, the American Society of Civil Engineers and the Wind Hazards Reduction Coalition.
The Louisiana State University Hurricane Center. Louisiana State University is the flagship institution of the State, classified by the Carnegie Foundation as a Doctoral/ResearchExtensive University. The university has a long history of research in hurricanes, coastal sciences and engineering. The LSU Hurricane
Center was founded and approved by the Louisiana Board of Regents in the year 2000 to provide a focal point for this work, with a mission to advance the stateofknowledge of hurricanes and their impacts on the natural, built, and human environments; to stimulate interdisciplinary and collaborative research activities; to transfer new knowledge and technology to students and professionals in concerned disciplines; and to assist the state, the nation, and the world in solving hurricanerelated problems. Research efforts that have been translated into practice in support of emergency management agencies include: implementation
of realtime storm surge modeling; improvements in hurricane evacuation planning and operations (particularly contraflow evacuations), and improvements in hurricane shelter analysis and design methods.
The American Association for Wind Engineering (AAWE) was originally established as the Wind Engineering Research Council in 1966 to promote and disseminate technical information in the research community. In 1983 the name was changed to American Association for Wind Engineering and incorporated as a nonprofit professional organization. The multidisciplinary field of wind engineering considers problems related to wind and associated water loads and penetrations for buildings and structures, societal impact of winds, hurricane and tornado risk assessment, costbenefit analysis, codes and standards, dispersion of urban and industrial pollution, wind energy and urban aerodynamics.
Founded in 1852, the American Society of Civil Engineers (ASCE) represents more than 125,000 civil engineers worldwide and is the nation’s oldest engineering society. ASCE members represent the profession most responsible for the nation’s built environment. Our members work in private practice, industry, government and academia. ASCE is an American National Standards Institute (ANSI) approved standards developer and publisher of the Minimum Design Loads for Buildings and other Structures (ASCE7), which is referenced in the nation’s major model building codes. As part of the ASCE7 document, engineers are provided guidance in estimating the loads resulting from wind effects on structures. Thus, ASCE is at the forefront in the development of new information for engineers regarding wind and is in a unique position to comment on the status quo and our needs for the future.
The Wind Hazard Reduction Coalition currently represents 23 associations and companies which are committed to the creation of a National Wind Hazard Reduction Program (NWHRP) that would focus on significantly reducing loss of life and property damage in the years to come. The Coalition includes professional societies, research organizations, industry groups and individual companies with knowledge and experience in dealing with the impact of high winds.
Problems and Solutions
All 50 states are vulnerable to the hazards of windstorms. Just last year, four hurricanes made landfall in Florida and caused severe damage. Losses from the 2004 hurricane season are estimated to exceed $40 billion to date and are still being counted. These storms resulted in 27 federal disaster declarations covering 15 states, the Virgin Islands and Puerto Rico. In 1998, hurricanes, tornadoes and other wind related storms caused at least 186 fatalities and more than $5.5 billion in damage. During the week of May 410, 2003, a record 384 tornadoes occurred in 19 states, including Kansas, Missouri, Oklahoma and Tennessee resulting in 42 fatalities. On May 3, 1999, more than 70 violent tornadoes struck from north Texas to the Northern Plains. Fortyone people died and more than 2,750 homes were damaged. In 1992, Hurricane Andrew resulted in $26.5 billion in losses and 61 fatalities, in 1989, Hurricane Hugo resulted in $7 billion in losses and 86 fatalities and in 1999, Hurricane Floyd resulted in more than $6 billion in losses and 56 deaths.
One major effort currently underway to reduce the loss of life and injuries in hurricanes and tornadoes is the development of a national standard for storm shelters. The International Code Council (ICC) and National Storm Shelter Association (NSSA), with support from the Federal Emergency Management Agency (FEMA), are currently developing the ICC/NSSA Standard for the Design and Construction of Storm Shelters. The purpose of the standard is “to establish minimum requirements to safeguard the public health, safety, and general welfare relative to the design, construction, installation, repair, operation and maintenance of storm shelters constructed for refuge from high winds associated with tornadoes and hurricanes.” Scheduled to be completed next year, this consensus national standard has the potential to significantly improve shelter safety.
In tornadoprone areas, the Storm Shelter Standard could be particularly helpful with regard to assuring a minimum level of performance for manufactured residential shelters, i.e., providing a basic consumer protection. The biggest immediate impact of the standard in hurricaneprone areas will likely be for community shelters. This is because the majority of buildings currently used as public hurricane shelters are inadequately constructed to resist an intense hurricane, placing the occupants at risk. This fact was demonstrated during the 2004 hurricane season in Florida. Supported by the ICC and Louisiana Sea Grant – LSU Hurricane Center researchers spent time in the field after Hurricanes Charley and Ivan, investigating performance of hurricane shelters. Of the two dozen shelters surveyed, those built to Florida’s Enhanced Hurricane Protection Area (EHPA) criteria outperformed shelters not built to those criteria. Damage to EHPA facilities was generally limited to minor water leakage. In other facilities, roof damage and water penetration serious enough to cause people to evacuate the shelter space was not uncommon.
Publication of the standard alone will not improve shelter safety though; it is just the first step in the process. Unless it is adopted and enforced by jurisdictions having authority over building construction, or voluntary compliance with the standard is requested or agreed to by the facility owners, the standard will have
little impact. Therefore, a significant awareness and education campaign will be needed. It must be addressed to architects, engineers, building officials, shelter owners (e.g., homeowners, school boards, city governments) and shelter operators (e.g., American Red Cross, emergency management agencies).
One of the biggest challenges facing design of public hurricane shelters is that shelter operators are not the owners of the shelter facilities and are rarely involved in the planning and design process. When faced with tight budgets and many competing needs, spending additional construction dollars to harden the
facility for use as a hurricane shelter is usually a low priority with the facility owner, even though the owner is often a public entity and tax dollars are funding the construction of the new school or municipal building. Unless able to obtain a mitigation grant from FEMA or perhaps a state agency, the local government or
the school district generally has to bear the increased construction costs associated with constructing the facility for dual use as a shelter. This is an area where additional engineering research and technology transfer is crucial – improving costeffectiveness of storm shelters.
Another hurricane sheltering issue relates to getting the message out about who should be going to shelters and who should be advised to shelter in place. Emergency managers generally only order mandatory evacuations for areas subject to significant hurricane flooding. This is done in order to make sure there is sufficient transportation system capacity available for people in the most atrisk areas. As coastal population growth continues to outpace construction of new highway infrastructure – more and more people will not be able to evacuate and need to seek shelter in their own residences or other local facilities. The National
Weather Service, National Hurricane Center and television media do comparatively good job of informing the public about the hazards they can expect with the approaching storm, but what information do people have about the relative safety of their home or business or shelter, so that they can make an informed decision about where is the safest place? If they are under a voluntary or precautionary evacuation warning, should they leave or stay? This is an area where better coordination and collaboration between the engineering community, emergency management community, and meteorology community is desperately needed.
Catastrophic hurricane planning is another area where much additional work and collaboration between the different professional communities is needed. Hurricane Georges in 1998 and Hurricane Ivan in 2004 both had the potential to drown the city of New Orleans and much of the surrounding southeast Louisiana
under 1020 feet of water. Estimates are that only 5060% of the residents evacuated for these storms, meaning over half a million people were at significant risk. Warned or not, if people have not evacuated and the water comes, there will be mass fatalities. Last year the Louisiana Office of Homeland Security and Emergency Preparedness and FEMA (and many other federal and state agencies) conducted a weeklong joint planning exercise on how to respond and recover from just such a scenario. This event helped produce the first catastrophic hurricane response plan, but it also raised more questions than it answered.
Hurricane Lili in 2002 raised similar fears. As the Category 4 hurricane approached the Louisiana coast on the evening of October 2, it appeared to begin moving farther east than had been predicted, into areas that had not been as well evacuated. Frantic preparations began to start identifying buildings to serve as refuges of last resort. Fortunately the storm returned to its more westerly track and rapidly lost strength before making landfall, and Louisiana dodged another bullet. This event highlighted the importance of plans of last resort – for situations where a storm makes an unexpected turn close to shore or rapidly intensifies,as Hurricane Opal did in 1995 when it accelerated and explosively intensified overnight to unexpectedly threaten the Florida panhandle.
Hurricanes also have impacts well beyond the regions where they make landfall. Price and availability of construction materials across the country are adversely affected by major storms such as Hurricane Andrew and the Hurricanes of 2004. Hurricane Ivan significantly disrupted offshore oil and gas production and transportation in the Gulf of Mexico, impacting energy prices nationwide. Fortunately, none of last years hurricanes impacted the onshore. This is another area of significant concern.
A study of industry practices published in 1997 by ASCE found that the wind resistant design of onshore refineries and petrochemical plants varied tremendously due to the aerodynamic complexity of the types of structures involved and the lack of coverage of these types of structures in any building codes or standards. An unexplored aspect of this report is that many industrial plants do not understand how vulnerable their processing and storage facilities may be to extreme winds. Many plants specify a wind speed to which their facilities should be designed, but because of uncertainties in how the wind interacts with the complex structures, the actual wind the structure can resist might be much larger or smaller. In practical terms – the actual design strength may be more than one SaffirSimpson Hurricane Category less than or greater than the intended design. In most cases the owners/operators of the facilities are unaware of this discrepancy, which is very important considering that decisions on whether to shut down a plant are generally based on the expected Hurricane Category at landfall. Additional study is needed to further define this problem, and cooperation with this industry and the preparedness/response community.
The problems and solutions described so far are just a few examples of areas in which more work and closer coordination is needed between industry, government, and the engineering community. The United States currently sustains billions of dollars per year in property and economic loss due to windstorms. The Federal government’s focus has been one of response and recovery, not mitigation. While there will always be a need, a sustained focus on hazard mitigation can lessen the cost in life and property of these events.
With the average annual damage from windstorms at more than $6 billion, the current $510 million Federal investment in research to mitigate these impacts is inadequate. In contrast, the Federal government invests over $100 million per year in reducing earthquake losses through the National Earthquake Hazards Reduction Program, a program that has lead to a significant reduction in the effects of earthquakes. A Federal investment in wind hazard reduction would pay similar or greater dividends in saved lives and decreased property damage.
Nearsurface winds are the most variable of all meteorological elements, making the prediction and control of their impacts all the more challenging. In the United States the mean annual wind speed is 8 to 12 mph, but wind speeds of 50 mph occur frequently throughout the country, and nearly every area occasionally experiences winds of 70 mph or greater. In coastal areas of the East and Gulf coasts, tropical storms may bring wind speeds of well over 100 mph. In the middle of the country, wind speeds in tornadoes can be even higher.
Unfortunately, reducing vulnerability to wind hazards is not just a question of developing the appropriate technical solution. Wind hazards are created by a variety of events with large uncertainties in the magnitudes and characteristics of the winds. The relevant government agencies and programs, as well as the construction industry, are fragmented. Finally, implementation requires action by owners and the public, who may not consider hazard reduction a high priority. Solving wind vulnerability problems will require coordinated work in scientific research, technology development, education, technology transfer and public outreach.
In 1993, the National Research Council (NRC) published a report entitled “Wind and the Built Environment.” The report included the recommendations of the Panel on the Assessment of Wind Engineering Issues in the United States. The panel recommended the establishment of a national program to reduce wind
vulnerability. Such a program would include wind research that draws upon the expertise of both academia and industry and addresses both structural and nonstructural mitigation methods, an outreach program to educate state and local governments on the nature of the wind risks they face, a conscious effort to improve communication within the wind community and a commitment to international cooperation in windengineering.
A 1999 NRC study concurred with that recommendation and specifically urged Congress to designate “funds for a coordinated national windhazard reduction program that encourages partnerships between federal, state and local governments, private industry, the research community, and other interested stakeholders.”
In 2003, the Rand Corporation released a report entitled, “Assessing Federal Research and Development for Hazard Loss Reduction”. Specific recommendations for a research and implementation program are contained in the report released by the American Association for Wind Engineering and the American Society of Civil Engineers entitled “Wind Engineering Research and Outreach Plan to Reduce Losses Due to Wind Hazards.” Both reports support programs which would encompass four focuses:
· Understanding of Wind Hazards - developing a greater understanding of severe winds, quantify wind loading on buildings, structures and infrastructure and developing wind hazards maps
· Assessing the Impact of Wind Hazards – assessing the performance of buildings, structures and infrastructure under severe winds, developing frameworks and tools for simulations and computer modeling and developing tools for system level modeling and loss assessment;
· Reducing the Impact of Wind Hazards – developing retrofit measures for existing buildings, structures and infrastructure, developing innovative windresistant technologies for buildings, structures and infrastructure and developing land measures and cost effective construction practices consistent with sitespecific wind hazards; and
· Enhancing Community Resilience, Education and Outreach – enhancing community resilience to wind hazards, effective transfer to professionals of research findings and technology and development of educational programs and public outreach activities.
From these reports and the efforts a number of Senators and Members of Congress, as well as the Wind Hazards Reduction Caucus, the National Wind Storm Hazards Reduction Program was born. Created by Public Law 108360, the legislation represents five years of work in which stake holders representing a broad crosssection of interests such as the research, technology transfer, design and construction, and financial communities; materials and systems suppliers; state, county, and local governments; the insurance industry, have participated in crafting this legislation. This bill represents a consensus of all those with an interest in the issue and a desire to see the benefits this legislation will generate.
Among the potential research area this program can explore are the numerous areas where we lack the knowledge to make informed judgments with respect to building siting and design. With data learn from research in the following areas, and other not yet foreseen, better knowledge and data will lead to costeffective design and construction practices to mitigate the impacts of high winds.
Boundary Layer Meteorology for Landfalling Storms - We know very little about the structure of the wind in a hurricane and how it changes as it passes over land. Research is needed to better understand the nature of boundary layer transitions, turbulence, rainfall, and decay rates as storms move inland. The design wind speed and gust factors used in all building codes and standards (including ASCE 7) are based on a set of assumptions that hurricane winds have similar properties to winds from other events, which we know to be untrue. This research can lead to significant improvements in windloading related portions of
our building codes and standards.
Rapid Damage Assessment using Remote Sensing for Improved Response and Recovery - The key to optimization of response and recovery operations is timely access to detailed information on the extent and intensity of damage throughout the effected areas. Very high resolution data can be obtained from commercial satellitebased remote sensing systems, which was previously unavailable except to intelligence and defense communities. Resolutions have improved to the point where data is available on individual buildings and vehicles. Development of computerized analysis tools that automate and map damage assessment estimates will significantly assist response and rescue and recovery operations.
Improved Connections and Framing Systems for Light Frame Construction - Much of the structural damage which occurs in severe winds is to light frame oneand twostory construction. There has been relatively little improvement in wood and other light framing technology in the past 20 years. New costeffective
construction techniques could significantly reduce structural damage to lowrise buildings.
Roof System Testing Procedures and Devices for Wind Resistance - No standardized testing procedures and devices exist to test roof cladding materials for resistance to extreme winds and debris. Development of these items is a necessary prerequisite for improved roofing performance (see next item).
New Roofing Systems - Damage to roofing is perhaps the single most common source of wind damage. Even small failures can allow the wind and rain inside the building leading to significant interior and contents damage and possible structural failure. Development of new windresistant roofing materials and technologies could significantly reduce windinduced damage.
In-Residence Shelters for Hurricane Protection - In collaboration with the university research community, FEMA has conducted research and developed plans and guidelines for inresidence shelters for protection from tornadic winds. These designs provide near complete protection for occupants from even large
tornadoes, but are too costly and overly conservative for use on hurricane coast. New research is needed to find more appropriate and cost effective solutions for construction on the hurricane coast.
DualUse Public Hurricane and Tornado Shelters - Schools are the most commonly used buildings for hurricane evacuation shelters, but they are not structurally designed to provide a safe haven. Similarly, children shelter in place while in school during tornado warnings, but these buildings too are not designed with adequate protection. Research and development of design guidelines and methodologies on how best to construct schools and other public buildings for dual function as shelters from hurricanes and tornadoes is desperately needed.
Retrofit Technologies for Wind Resistance - Although it is much easier to build wind resistance into new construction, the country has an enormous investment in existing building stock. Technologies for costeffective retrofits to improve wind resistance of these buildings should be an important focus of any new research program.
Congress has taken action to establish a program to mitigate the impact of severe windstorms. What is needed in the immediate future is funding for the new program. I would urge members of the Subcommittee to work with your colleagues in the Appropriations Committee to ensure that the Windstorm Hazards Reduction Program can begin the work it was designed to do. For Fiscal Year 2006 the program is authorized for $22.5 million dollars in spending, spread over four agencies. Specifically, the law authorizes:
· $8.7 million for the Federal Emergency Management Agency;
· $3 million for the National Institute of Standards and Technology at the Department of Commerce;
· $8.7 million for the National Science Foundation; and,
· $2.1 million for the National Oceanic and Atmospheric Administration.
Once again, thank you for the opportunity to present the views of the many organizations I am representing here today. I would be happy to answer any questions that you might have.