Anniston, AL
6.09
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Table 9. Rainfall from Hurricane Opal, 1995, http://ww2010.atmos.uiuc.edu, 1999
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According to DAS (1999) the total number of flash flood deaths has exceeded tornado fatalities during the last several decades.
Two factors seem to be responsible for this: public apathy regarding the flash flood threat and increased urbanization. When concrete replaces soil, rain water will run off rather than soak in. Flash flood producing rainfall has made the dramatic water rescues frequently seen in the media all too familiar, especially in urban areas and popular mountain camping spots (DAS, 1999, http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/svr/dngr/flood.rxml).
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Implications of Severe Windstorm for Communities
The literature indicates that severe windstorms affect communities in many ways, but predominantly by (1) damage to structures from high wind; (2) flooding from torrential rains; (3) damaging hail; and (4) lightning. “Losses attributed to hurricanes, tornados, and local winds are estimated to total $0.5 to $2.0 billion a year in the United States” (Minor, 1988, p.87) Damage to buildings and other structures during windstorms is becoming a major problem for many communities. Minor (1988) identifies urban sprawl, and the decline in the quality of certain types of building construction, as key factors in the amount of damage that high winds can cause.
Studies of wind-induced damage indicate that the wind resistance of buildings is related to the amount of engineering attention given to them. Buildings classified as full engineered, pre-engineered, marginally engineered, and non-engineered are, in that order, increasingly susceptible to wind damage (Minor, 1988, p.93).
An explanation of Minor’s terminology may be helpful. Minor describes the types of buildings in each of the categories of engineering as follows:
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Fully engineered-buildings are designed by professional engineers and architects. Pre-engineered buildings are planned as a group by engineers before construction and are marketed as individual units throughout the country. Marginally engineered structures make up the largest loss category in windstorms. These buildings are built with combinations of masonry, light-steel framing, open-web steel joists, wood framing, wood rafters, and concrete. Although these materials are used with success in engineered designs, they are often carelessly assembled and provide only minimal protection from wind-induced pressures (Minor, 1988, p. 94).
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Single-family and multiple-family residences, certain apartment units, and many small commercial buildings account for the vast majority of buildings that are not engineered. These buildings offer little resistance to lateral and uplift pressures induced by high winds because of their largely wood framed construction. “Weak roof-to-wall and wall-to-foundation connections, little resistance to lateral loads, and inadequate overall structural integrity typifies these buildings. They can be damaged by winds of 75 mph and total destruction may occur when winds reach 125 mph” (Minor, 1988, p. 95).
Tornados have a tremendous capacity to cause death and injury and destroy structures. Ebert (1988) wrote about the destructive power of a tornado and made the correlation between wind speed and dropping pressure in the vortex of the tornado.
The total destruction often caused by tornados is the result of their (1) extremely high rotary wind velocities, and (2) the partial vacuum that exists within the vortex . . . .Estimates based on engineering studies of tornado damage indicate that horizontal windspeeds in the vortex may be higher than 300 mph (Ebert, 1988, p.83).
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The low pressure inside the vortex can only be estimated since it is impossible to get measuring devices into the vortex of a tornado, unlike the eye of a hurricane where a plane can fly around. Ebert wrote that it is possible that the pressure may drop to as low as 17.7 inches of mercury, or about 60 percent of normal atmospheric pressure.
If the outside atmospheric pressure, caused by the passage of a hurricane, would drop anywhere from one to five inches of mercury, the net excess pressure inside a tight building could rise from 70 to 400 pounds per square foot. This pressure build-up, in combination with the force exerted by the high winds, can lead to a total disintegration of the structure (Ebert, 1988, p.84).
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While the strong, rotational winds associated with hurricanes and tornados are well known for their destructive capabilities, straight-line winds created by macrobursts and microbursts have much potential for creating damage. “Strong straight-line winds accompany thunderstorms more often than tornados and may be as damaging to persons and property as a small tornado” (Kessler and White, 1988, p. 6).
Managing the Consequences of Severe Weather
Severe weather has the potential to bring a disaster to bear on a community both in the short term (thunderstorms and tornados) and the long term (hurricanes and floods). Any of these weather induced disaster events can create a multitude of emergency coordination and management problems for a community because these events differ greatly from daily emergencies.
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One of the reasons disaster response is difficult to coordinate is because disasters are different from routine, daily emergencies. Disasters generally cannot be adequately managed merely by mobilizing more personnel and material. Disasters may cross jurisdictional boundaries, create the need to undertake unfamiliar tasks, change the structure of responding organizations, result in the creation of new organizations, trigger the mobilization of participants that do not ordinarily respond to local emergencies, and disable equipment and facilities. As a consequence of these changes, the normal procedures for coordinating community emergency response may not be adapted well to the situation (Auf der Heide, 1989, pp. 49-50).
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Mikel (1998) discussed the impact of thunderstorms on the town of Naperville, IL and the affect of those storms on the local fire department. Over a four-year period (1994-1997) Naperville recorded 25 structure fires caused by lightning strikes and 97 incidents of significant structural damage from lightning strikes that did not cause a fire. “During a thunderstorm, the department often handled as many calls in a one-half hour as it normally did in an entire 24-hour shift” (Mikel, 1998, p. 3).
Auf der Heide (1989) wrote that disasters are the ultimate test of a community’s emergency response capability. The ability to effectively respond to disasters is becoming more important because of factors that tend to increase: greater population densities, less stable building construction, inadequate building codes, etc.
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Unfortunately, there are recurring difficulties with disaster response. Lessons learned are not always being applied to other communities. Sometimes this is because accurate information regarding the basic underlying causes of the difficulties are not readily available to emergency and disaster responders (Auf der Heide, p.2).
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Kasperson and Pijawka (1985) wrote about the disaster response roles of federal, state, and local governments. According to the authors, the federal government has the most experience in managing disasters because of its disaster response role in all fifty states. Individual states have less experience because they are responsible only for disasters within their borders. Of the three levels of government, local governments have the least experience in managing disasters. “Local governments bear a large responsibility for disaster response because they are closest to the event and are apt to be on the scene before substantial state or federal resources are available” (Kasperson and Pijawka, 1985, p.13). Cigler (1986) in describing the disaster response relationships that exist among the three levels of government called this disparity in disaster response experience and disaster response responsibility the “intergovernmental paradox.”
The intergovernmental paradox refers to the fact that the local government, which is least likely to see disaster as a key priority, is most likely to be faced with the responsibility for carrying out disaster response. . . .The trend in the United States has been to place most of the responsibility for disaster response on local government (Cigler, 1986, p.8).
Auf der Heide (1989) wrote that local governments and officials may be held financially liable for certain consequences of disasters if their community were not prepared or did not respond properly.
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“A loss due to disaster can be recovered in court if the victim can show: (1) the governmental body owed a duty to the victim to avoid, prevent, or lessen such a loss; (2) that the body failed to carry out this duty; and (3) that the loss occurred as a result of this failure” (Kusler, 1985, p. 119). Kusler also wrote that the exposure liability for local government has also become greater. He listed several factors that may increase local government liability in the context of emergency response:
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The courts have recognized broadened concepts of the duties and responsibilities of local government.
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The “act of God” defense for disaster losses is less frequently accepted by the courts.
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The ability of local governments to claim “sovereign immunity” has been substantially reduced.
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The duty of governments to develop disaster countermeasures is becoming more frequently stipulated in legislation (Kusler, 1985, p. 120).
Graham (1997) spoke of the concept of public safety agencies applying risk management principles to their application of policy and procedure. Graham stated that just as the safety manager looks at risk and frequency to mitigate risk and improve safety, any agency that provides emergency services to the public can use that same examination to identify needed policy and procedure. Further, the agency can identify which policies have the most risk and design training that enhances the knowledge of policy by response personnel to increase the likelihood that the policy will be followed, thus decreasing the risk (See Figure 1 on next page).
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Figure 1. Risk/Frequency Analysis of Policy and Procedure (Graham, 1997).
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In Figure 1, Graham’s statement is that those policies and procedures with the highest risk and the lowest frequency constitute the greatest liability (consequences) to emergency response organizations. He further spoke that those policies can be subdivided into the categories of non-discretionary time (NDT) and discretionary time (DT) policies. NDT policies are those policies where the situation provides little or no time to reference the applicable policy–personnel have to have a deeply ingrained knowledge of the policy for effective decision making and action to take place, thus minimizing the risk. DT policies cover those situations where time does exist to reference the policy, i.e., through checklists, field guides, etc., to make effective decisions. Graham contends that such informed decision-making results in proper conduct at an operation rather than the organization having to deal with the consequences of a poor decision (See Figure 2 on next page).
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Figure 2. Risk Management to ensure proper conduct at incidents (Graham, 1997)
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Managing Fire Department Operations at Severe Storm Emergencies
Cowardin (1981) wrote that every officer in charge of an incident, whether volunteer or part-time, acting, temporary or career oriented, needs a method by which direction can be given to emergency forces under his\her control.
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The problem with the fire service's lack of direction for emergencies is that we do not build a system of management which can be applied to day-to-day situations as well as a problem which may double or triple the size of the department. Therefore, a breakdown occurs in the management structure right at the point where the emergency reaches its most critical stage (Cowardin, 1981, p. 7).
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As described earlier in this literature review, Auf der Heide and others make the case that response to disaster emergencies is different from that required for daily operations. Auf der Heide (1989) wrote that disaster planners would be best served not to attempt to develop plans and operations based on a “worst-case” disaster scenario.
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He argues that such planning (1) amplifies public and responder apathy (“can’t happen here mentality”); most disaster research in the United States has focused on moderate events involving tens to hundreds of casualties; and (3) applying limited resources to the most improbable type of disaster (“the big one”) is not cost effective. “Planning should be for disasters of moderate size (about 120 casualties); disasters of this size should present the typical inter-organizational coordination problems that are also applicable to larger events” (Auf der Heide, p. 25).
In the course of this literature review the author was able to locate very few pieces that describe fire department response procedures to such weather related incidents as thunderstorms, tornados, hurricanes, etc. The majority of sources researched were of the anecdotal or historical nature–they described what happened, but provided very little information on how the departments involved managed incidents using policies and procedures that they had in place prior to the event. Two courses at the National Fire Academy, Command and Control of Fire Department Operations at Natural and Man-made Disasters, and Executive Analysis of Fire Service Operations in Emergency Management, provided the most in-depth information on preparing for and conducting fire department operations at storm related emergencies.
FEMA (1994) identified the critical components that should be part of a fire department’s policies and procedures for response to natural and man-made disasters. Following Auf der Heide’s recommendations that disaster planning should focus on addressing the needs of the moderate sized disaster, the type a community has a likelihood of encountering, these critical components would seem to be appropriate for severe weather emergencies.
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Those critical components are identified as:
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Situation assessment and size-up
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Identifying incident objectives
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Developing an organization to manage the incident
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Develop a system of resource management
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Develop a communications plan
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Develop an incident safety plan
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Develop an incident medical plan (FEMA, 1994, pp. 3-5 to 3-6).
Situation Assessment and Size-up
FEMA (1994) describes this component as necessary direction on how to provide for security of department resources and personnel (while fulfilling first responder requirements during the initial stage of a major incident or disaster). This component should also address the need to provide command with information on what has happened, the scope and magnitude of the incident. This assessment has two basic functional tasks that must be completed–the impact of the event on emergency resources and facilities and the impact on the community. The former should be completed as soon after the precipitating event as possible.
Ensure the safety of yourself and your co-workers. Assess the condition of:
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