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Photo credits: © Can Stock Photo / fotolotti and © Can Stock Photo / Modelist INTRODUCTION wind speed maps. In the last 50 years, rately calculate costs related to the loss of In the United States, extreme wind expenses related to extreme wind events people and animals, especially pets. The events occur each year, causing substantial have climbed into the billions of dollars per more important question is this: Are we physical harm to people and damage to the year for repair or replacement of property more concerned about the loss of property buildings they occupy. This article will pro- damage alone. than the loss of human life? Both are obvi- vide design and construction-related profes- The cost estimates from the destruction ously important because buildings that fail sionals with U.S. inland historical data and related to extreme wind events are higher due to high wind speeds sometimes kill, suggested design options via possible future than most recognize since no one can accu- maim, or injure the people inside. Figure 1A – Safe room wind speed map 2015 (courtesy of the ICC). Figure 1B – FEMA map (courtesy of FEMA). 10 • RCI I NTE R FA C E J ANUA R Y 2 0 1 9 Figure 2A – ASCE 7 2005, western part of U.S. (courtesy of ASCE 7). Figure 2B – ASCE 7 2010 Risk Category I. Also found in IBC 2012 code. (Courtesy ASCE.) The use of statistical percentages for wind events is outdated, such as one tornado per a certain number of years ing to those who are (e.g., 50 or 300 years), and does not jus- physically challenged tify our current low inland wind speed and cannot make maps. Therefore, the old statistical reason- it to the designated ing that promoted lower inland building- safe room within the related wind speed maps is considered allotted tornado-type obsolete as a premise for this article. This warning time. Per article will provide some common-sense published data by perspective to the question posed above the National Oceanic and the suggested new wind maps that and Atmospheric Ad- are reasonable based on historical data. ministration (NOAA) International building codes already contain in March 2017, limited special wind zones, and more wind the time is limited zones are proposed from other entities. —under 13 min- Our industry needs to adopt practical utes’ notification on wind speed maps that correspond to his- average—to find a torical extreme wind events. The old saying safe room after an “speed kills” is applicable when discussing extreme wind event anticipated tornado wind speed forces on warning alert. In fact, buildings and the safety of U.S. citizens. safe room code devel- Based on the havoc unleashed by recent opment and related tornadoes (i.e., Joplin, MO, 2011), the lat- adoptions that have est International Code Council (ICC) codes been code-imple- responded to the extreme wind events by mented only support implementing codes for safe rooms that the claims made in are based on recent wind speed maps this article that the Figure 2C – ASCE 7 2016 Risk Category I (courtesy of ASCE 7). (Figure 1A). Other organizations, such current building code as the Federal Emergency Management wind speed maps are insufficient for build- force wind speeds from 64 to 72 mph. Administration (FEMA), have adopted the ings in general and are in need of updating Regardless of charts, 32-mph wind events codes for shelters (Figure 1B). (Figure 2). and the high end of the Enhanced Fujita Safe rooms are a good starting point, (EF) Tornado Scale (EF 5, or above 200 but they are not enough to ensure the Wind Speed History and Code MPH) will be the definition of an extreme safety of people working or residing in Background wind force for this article. these tornado-prone areas. In fact, safe The Gale Force Wind Speed Chart lists Loss of life and property via extreme rooms could be construed as discriminat- wind speeds from 32 to 63 mph and storm wind events has been primarily from J ANUA R Y 2 0 1 9 R C I I NTE R FA C E • 1 1 (shaded areas) on the ASCE 7 wind speed maps (Figure 2). Therefore, another ques- tion arises: Why are peo- ple and property along the coastlines (in hurricane zones) better protected by building codes than people and property elsewhere in the U.S.? Governmental agencies such as FEMA and com- panies such as Factory Mutual Global (FMG) have developed their own extreme wind speed maps or adopt- ed others that are mostly based on wind event his- torical data. FMG has rec- ognized the deficiency of represented inland contour Figure 3 – FMG recommended wind speed maps (FMG Tornado Design Guidance Map 2015, courtesy of FMG). lines in the codes and has added a recommended wind horizontal rotational winds such as tor- the American Meteorological Journal speed map that includes historical extreme nadoes and hurricanes. Other types of by Dr. Gustavus Hinrichs, professor wind event areas (recommended wind speed extreme wind events can be associated with of physics at the University of Iowa. maps for tornadoes in the current FMG derechos. A derecho is described as a fast- • Over 100 hurricanes hit the coasts Data Sheet 1-28, Appendix D, Optional moving wind in a straight line or a cluster of of the U.S. in the 19th century, kill- Guidance for Tornado-Resistant Design and wind downbursts with air microbursts with- ing thousands and damaging prop- Construction). See Figure 3. The recently in the cluster. Author Tim Marshall sum- erty. produced map by FMG is similar to others marizes this point in stating, “Wind is wind” • An unnamed hurricane struck that have made allowances for safe rooms, when discussing wind events. Regardless of Galveston Island, Texas, on such as the 2016 ASCE 7, page 759, or the the types of extreme wind events and their September 8, 1900, with virtually ICC map (Figure 1A). damaging effects on people or property, no warning. The death toll was stag- The changes of the wind speed maps for they have not been prominently recorded in gering, with estimates from 6,000 to safe rooms/shelters represent progress, but ancient history compared to other natural 12,000 lost. a recommendation would be the inclusion of disasters. a common-sense approach to create nation- Scientists and archaeologists have In the 21st century, numerous design al wind speed maps for the entire building unearthed evidence of ancient natural wind speed maps have changed slightly for based on extreme wind event historical disasters through means of relative dat- distinct reasons, according to a committee data. This approach would be much more ing techniques and have communicated of the American Society of Civil Engineers comprehensive in addressing the safety of approximately when and where volca- (ASCE). These changes are noted in the humans and animals in inland areas. noes, earthquakes, and flood events have ASCE 7, Design Guide for Buildings and Historical wind speed data have only occurred. That is not the case with extreme Other Structures standard. (Recent revisions been a viable tool in recent history based wind events. One of the rare accounts of have ensued in 2005, 2010, and 2016; on improvements in weather tracking and an extreme ancient wind event is found in see examples in Figure 2.) The recent wind forecasting technology. A massive quantity the ancient book of Job, chapter one, verse speed map changes related to risk factors of detailed historical wind speed data have nineteen: “And behold, a great wind came among the ASCE 7 publications have been been accumulated over the last 100 years from across the wilderness and struck the confusing. Based on review of the wind from NOAA (and other weather entities) and four corners of the house, and it fell on the speed maps over several editions of ASCE is available for further analysis in relation young people and they died.” The book of 7, wind speed map contour lines do not to the inland states’ anticipated extreme Job dates to the 4th century BC or earlier. increase inland (noncoastal) for buildings wind speed killer events. Wind speeds are Most extreme wind events in history hap- and, therefore, are not proportionate to the categorized via wind speed scales such as pened without leaving a trace except for recorded extreme inland wind events—at Saffir-Simpson for hurricanes and with the last few centuries, where there is some least in the last two decades. the original Tornado Wind Scales Fujita (F) historical data. Excerpts of some events are Based on the evidence, it appears that 1971, plus the Enhanced Fujita (EF) 2007 listed below. the wind speed maps are largely discrimi- that were created to give perspective on • In 1888 in the state of Iowa, a dere- natory to the areas that are not along the wind destruction to buildings (Figure 4). cho was observed and published in coastlines or in the special wind regions 12 • RCI I NTE R FA C E J ANUA R Y 2 0 1 9 Figure 4A – Tornado wind scales (EF post 2007). Figure 4B – Hurricane wind scale. Note: Hurricane/tornado scale wind speeds (or categories) represent minimum sustained wind speeds (via anemometer per a time unit) or wind speeds that have been determined by building or site damage in the aftermath. Hurricane/tornado scales are generally compared to other wind speed maps in this article (such as Figure 2 maps), which may or may not have the same methods to determine minimum wind speeds or categories of wind speed.

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