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1.
Death tolls from tornadoes in Bangladesh are the highest in the world due to lack of storm warnings, poor communication, weak
housing, and lack of shelters from strong winds in tornadoes and nor’westers. Based on surveys of housing types and designs
in the Tangail district, a household tornado shelter is proposed to be placed in the elevated storage platform that is common
in houses. The shelter is 2 m tall, 1.2 m wide, and 2–4 m long (4.8–9.6 m3 in volume) with the floor of the shelter placed one meter below the floor of the house. Walls are 7–10 cm thick and made
of concrete or an earthen wall stabilized with cement or strengthened with bamboo or bricks. A survey of 200 residents of
the region found nearly universal acceptance for the shelter design, and residents were eager for installation of the household
shelters. The shelter cost is 2,500–10,000 taka (US50 to50 to 200) depending on local material and labor costs but residents
were willing to pay an average of only 1,071 taka (US$21) toward the cost of the shelter. Families with greater income and
land holdings and families in villages with recent tornado experience were willing to spend more for a shelter. A pilot project
to install household tornado shelters in selected villages and monitor their use, along with continued efforts to issue storm
warnings, communicate the warnings, and improve education about storm hazards, will prevent injuries and save lives in Bangladesh
and reduce the descent into poverty that results from losses in severe local storms. 相似文献
2.
Tornado shelters and the manufactured home parks market 总被引：2，自引：2，他引：0
Manufactured or mobile homes represent a fast growing portion of the housing market but are particularly vulnerable to tornadoes.
In the US over 40% of tornado fatalities occur in mobile homes even though they comprise about 8% of US housing units. We
examine the market for tornado shelters in manufactured home parks in Oklahoma. Almost 60% of parks in the state have shelters,
with 90% of the shelters underground. Parks with shelters are not concentrated in urban areas but spread across the state,
with parks with shelters in 32 counties. We find that rents for lots in parks with shelters are 5–8% higher, which generates
sufficient revenue to approximately pay for shelters, but the point estimate is statistically significant in only one specification.
相似文献
| Daniel Sutter (Corresponding author)Email: |
3.
Kevin D. Ash 《GeoJournal》2017,82(3):533-552
Occupants of mobile or manufactured homes in the United States of America (USA) are highly exposed and susceptible to injury or death from tornado hazards. This problem is most pronounced in the southern and eastern USA, where tornadoes are frequent and mobile homes comprise upwards of 15 % of the housing stock. Recognizing this vulnerability, emergency management entities and the USA National Weather Service often recommend that mobile home residents evacuate to a nearby sturdy building or a specially-built tornado shelter when tornadoes threaten their communities. Previous research suggests, however, that only 30 % of residents follow this recommendation. In this research I aim to provide insight as to why many mobile home residents seldom undertake the suggested course of action for tornadoes. Using excerpts from twenty semi-structured interviews conducted during 2013 in South Carolina, I show that some individuals understand physical characteristics of tornadoes very differently than experts do. In addition, mobile home residents may also hold views that differ from experts about the ability of their homes to withstand tornadic winds and debris. Even if mobile home occupants pay close attention to thunderstorm hazards and might be willing to evacuate, they may prioritize protective actions for lightning or flash flooding over those recommended for tornadoes. Finally, the interviews reveal that there is much confusion over where to go, when to leave, and which route to take to arrive safely at a sheltering place for tornado hazards. I discuss some of the potential ramifications of the findings for theory and practice and suggest how future research might build on this work. 相似文献
4.
Kathleen Sherman-Morris 《Natural Hazards》2010,52(3):623-638
An online survey was completed by 2,921 students and employees at a large university following a tornado near-miss that required
taking shelter. During this event, the university’s emergency alert messaging system was tested. The first alert message was
received by over 66% of the sample within 15 min, and cell phones were the most common means of receiving this message—especially
for students. Employees relied more on computer instant messaging than did students. Interpersonal communication was also
important. The majority could correctly define tornado watch, tornado warning and shelter in place. Age and frequency of use
of weather information were of mixed significance as predictors. Finally, over three quarters of respondents reported taking
shelter during the event. Being female and being an employee made a respondent more likely to take shelter. 相似文献
5.
Krocak Makenzie J. Ernst Sean Allan Jinan N. Wehde Wesley Ripberger Joseph T. Silva Carol L. Jenkins-Smith Hank C. 《Natural Hazards》2020,102(3):1351-1368
When the National Weather Service (NWS) issues a tornado warning, the alert is rapidly and widely disseminated to individuals in the general area of the warning. Historically, the assumption has been that a false-negative warning perception (i.e., when someone located within a warning polygon does not believe they have received a tornado warning) carries a higher cost than a false-positive warning perception (i.e., when someone located outside the warning area believes they have received a warning). While many studies investigate tornado warning false alarms (i.e., when the NWS issues a tornado warning, but a tornado does not actually occur), less work focuses on studying individuals outside of the warning polygon bounds who believe they received a warning (i.e., false-positive perceptions). This work attempts to quantify the occurrence of false-positive perceptions and possible factors associated with the rate of occurrence. Following two separate storm events, Oklahomans were asked whether they perceived a tornado warning. Their geolocated responses were then compared to issued warning polygons. Individuals closer to tornado warnings or within a different type of warning (e.g., a severe thunderstorm warning) are more likely to report a false-positive perception than those farther away or outside of other hazard warnings. Further work is needed to understand the rate of false-positive perceptions across different hazards and how this may influence warning response and trust in the National Weather Service.
相似文献6.
Tornadoes are one of the most powerful and destructive weather events. The frequency of tornado occurrence is highest in North America, especially in the US Canada is second only to the US, and approximately, 80 occurrences are reported annually. Communities are impacted only when and if a tornado touches down on the ground. Early recognition of tornadoes and proper communication of warnings in the pre-touchdown phase helps the public to be ready and respond appropriately and effectively. Given that tornadoes are hard to predict and the warnings give only a very brief window of opportunity to prepare for evacuation to a secure underground or other location, each activity in the detection and warning phases is critically important. This study is focused on conducting a detailed comparison of the tornado detection and warning systems in the US and Canada. The sequences of activities and their interrelationships in the tornado detection and warning systems of each country are identified and developed as networks. A detection and warning network for Canada is developed, using Calgary as a case study, whereas a separate network is developed for the US, showing how local residents receive tornado warnings initiated by a local weather forecast office. Moreover, collaborating partners are identified, and their involvement at each level of the information flow is recognized. The two networks are compared and critically analyzed, focusing on the key issues, such as prediction/detection capabilities, warning decision-making, warning dissemination methods, and the spotters’ role. This qualitative comparison supports the recognition of key areas that need to be considered in improving the tornado detection and warning system in Canada. 相似文献
7.
A May 2007 tornado destroyed 95% of aging, declining Greensburg, Kansas. The city took the opportunity to build back “stronger,
better, and greener,” enforcing upgraded codes, requiring city-owned buildings to meet LEED Platinum level standards, and
recommending energy-efficiency housing in a new Sustainable Comprehensive Plan. Using information collected from surveys of
Greensburg tornado survivors, interviews, and publications, we examined the housing-related recovery, including the emergency
provision of temporary shelter and rebuilding permanently. Although temporary shelter kept residents nearby for rebuilding,
given the gap between insurance policy limits on the aging housing stock and rebuilding costs, housing affordability is a
critical issue in Greensburg’s recovery. Local, state, and federal support have made construction of municipal buildings at
LEED Platinum level and some affordable and green housing projects possible. However, far greater public and private sector
funding for affordable workforce housing, in conjunction with broader economic and job development, is needed. 相似文献
8.
One hundred school districts were surveyed along the Atlantic and Gulf of Mexico coasts from North Carolina to Texas. Nearly all had recent experience with a tropical storm or hurricane and had hurricane plans in place. About half teach hurricane preparedness to students and 85 % train staff members in hurricane preparedness. Sources of information about cyclone threats were the National Hurricane Center (91 %), local television news (74 %), The Weather Channel (67 %), and the internet (67 %). Only 36 % would cancel classes for a hurricane warning but 89 % would cancel classes for a mandatory evacuation. Most districts (75 %) would use schools as storm shelters, and 92 % would use school busses to assist in community evacuations. Districts with a higher percentage of Hispanic population provided hurricane information in Spanish. Larger school districts were less likely to cancel classes in the middle of the day for a storm threat. Districts with higher home values were less likely to use school busses for evacuations, and smaller school districts were less likely to provide schools as storm shelters. There were no other significant associations between hurricane preparedness of the districts and district demographic variables of poverty, percent black, percent Hispanic, population, district size, or median home values. 相似文献
9.
Anytime that tornadoes interface with people, the results are often grim. The varied characteristics of tornado windfields
and the diverse techniques of home construction complicate the expected outcomes of such interactions. Since it is now known
that tornadoes do not produce unfathomable winds, engineers have developed techniques for increasing a home’s tornado resistance;
thus, increasing the odds of survival of the inhabitants. Even considering these advances, tornadoes still wreak havoc and
cause much causality every year. The story of tornado survival is partly chance, partly knowledge, and partly science. This
essay utilizes analogies between a popular motion picture and the state of the art of tornado-resistant construction to illustrate
the good, the bad, and the ugly facts of tornado survival. First examined are the positive aspects of tornado probability.
The odds of experiencing a tornado are so low that massive expenditures are not necessarily cost effective. Next, various
techniques of tornado-resistant construction practices are included for new and existing structures. Introduction of equations
for predicting debris penetration are compared with various building techniques to describe the viability of tornado protection.
The negative aspect of tornado/structure interfaces describes the fact that despite contemporary construction and prevention
exercise, the unpredictability of the tornado windfield causes tremendous damage and loss of life. The final section examines
the interface between tornadoes and mobile homes. This proves very ugly in every aspect of the word. Statistics and equations
confirm the inherent dangers of such an interaction. Also, described is a novel approach to the design of a portable tornado
shelter. 相似文献
10.
Tornado fatalities and mobile homes in the United States 总被引：1，自引：1，他引：0
Fatalities from tornadoes have declined dramatically over the last century in the United States. Despite the overall reduction
in tornado lethality, fatalities from mobile homes remain high. In fact, research suggests that the likelihood of a fatality
in a mobile home is ten times or more than that in a permanent home. This study examines possible explanations of the mobile
home tornado problem, including the potential for concentration of these homes in tornado prone states, the relation to Fujita
Scale rating, and incidence during the day. We find that mobile home fatalities are concentrated in the Southeastern US, significantly
more likely in weaker tornadoes, and occur disproportionately at night. 相似文献
11.
This research provides an overview and discussion of language used in tornado safety recommendations along with development of a rubric for scaled tornado safety recommendations. Residents living in affected areas and those temporarily housed at relief stations were surveyed to collect information on their experiences during a 2-week period following the April 27, 2011 Tuscaloosa, Alabama EF4 tornado. Respondents were asked about their refuge plans during the storm and about any future changes to those plans. A specific focus of this research evaluated the adequacy of each respondent’s plan. Each refuge plan was compared using a tornado refuge rubric developed through the use of enhanced Fujita (EF) scale degree of damage ratings for available damage indicators. There was a significant difference in the counts of refuge adequacy for Tuscaloosa residents when holding the locations during the April 27 tornado constant and comparing adequacy ratings for weak (EF0–EF1), strong (EF2–EF3), and violent (EF4–EF5) tornadoes. There was also a significant difference when comparing the future tornado refuge plans of those same participants to the adequacy ratings for weak, strong, and violent tornadoes. This research introduces renewed discussion on proper refuge and shelter alternatives for days when violent tornadoes are forecasted. 相似文献
12.
Survey responses from 76 public school districts in Mississippi and Alabama were analyzed along with county-level demographics, tornado-path data, and tornado warning data to investigate the emerging trend of early dismissals. No two districts had identical responses, but the concern of safety was consistently mentioned. The highest number of reported dismissals would have resulted in a loss of <2 % of total annual class time. The rates of dismissals reported by districts were compared with tornado warning days to identify potential over-dismissal, which was found in 51 % of districts. Rates of dismissal and over-dismissal were analyzed with variables from survey responses, tornado warning data, tornado-path data, and county census data to determine variables that influence differences among districts. Various stepwise models indicate that districts with higher poverty levels could be less likely to dismiss. Permutation tests and stepwise models show that early dismissal and over-dismissal are more likely when a district: (1) has a higher number of killer tornadoes in the last 5 years, (2) has a higher number of recent injury-causing tornadoes, (3) has a higher number of total killer tornadoes since 1950, (4) is in a smaller county, (5) has dismissal decisions made by a team, (6) is a county district rather than a city district, and (7) has a lower level of poverty. The inverse relationship with poverty suggests that schools in poorer areas may be holding students in school because they consider them to be safer there than at home, or it could be due to a lack of resources at the school. All of these are based on a district’s location and plans, things that can be determined before a potential dismissal. These indicators can be used to highlight districts most likely to dismiss and possibly reduce rates of over-dismissal by alerting districts to their predisposed tendencies. 相似文献
13.
National Weather Service issues deterministic warnings in a tornado event. An alternative system is being researched at National Severe Storms Laboratory to issue Probabilistic Hazard Information (PHI). This study investigated how providing the uncertainty information about the tornado occurrence through PHI changes people’s protective actions. In an experiment, visual displays of the probabilistic information and deterministic warnings were presented to fifty participants to report their expected protective actions in different scenarios. It was found that the percentage of people who expected to immediately take shelter right after receiving the weather information increased exponentially as their proximity to the threat decreased. When there was more chance that the information about occurrence of a particular tornado was false rather than true, in scenarios that the likelihood of the threat occurrence was less than 50%, providing it through PHI lowered the percentage of people who immediately took shelter. The ordinal logistic regression models showed that the probability of taking protective actions significantly changes by providing the uncertainty information when people have less than 20 min lead time before getting impacted by the threat. When the lead time is less than 10 min, the probability of immediately taking shelter increases to 94 from 71%, and when the lead time is more than 10 but less than 20 min, that probability increases from 53 to 70%, if they are provided with the probabilistic information. Presenting the likelihood of any tornado formation in the area did not have significant effect on the people’s protective actions. 相似文献
14.
By employing a complete observation system, the underground erosion in a typical large-scale crystalline schist landslide
in Japan, the Zentoku landslide, was studied. It was found that the seasonal heavy rainfall is the main factor leading to
the massive underground erosion. Two types of sediment discharge of the landslide were defined. Monitored data indicated that
the movement of Zentoku landslide could be affected by the underground erosion following the concentrated heavy rainfall.
The influence of the underground erosion on the movement of the landslide presents different features. For the sliding block
of shallow and medium depth shear zones (5–20 m), the influence of the underground erosion is most outstanding, while it is
negligible for the sliding block of thick soil and rock layers (>30 m). Finally, the rainfall thresholds for the Zentoku landslide,
which concern the groundwater state, underground erosion and movement of sliding blocks, were provided to further establish
the warning and evacuation system. 相似文献
15.
Samanthi W. Durage Lina Kattan S. C. Wirasinghe Janaka Y. Ruwanpura 《Natural Hazards》2014,71(3):1495-1517
With increasing concerns over the possibility of tornadoes in highly populated areas in Canada, emergency managers are looking into ways to mitigate the impacts of tornadoes. Given that tornadoes can cause enormous destruction, early warnings and proper evacuation actions are critically important in helping save lives. In this paper, a survey was conducted to analyse the evacuation behaviour of households and drivers during a hypothetical tornado warning situation in the city of Calgary, Alberta. Nearly 500 Calgarians took part in the online survey and provided information on how they would respond to tornado warnings after receiving them. This paper presents the results of the survey. Using probit models, the factors influencing these evacuation decisions are identified and discussed in detail. The results of the household evacuation model show the importance of improving awareness about the safest locations during a tornado. It further highlights the need for targeting the population under the age of 30, who are more likely to take unsafe evacuation actions. The model for evacuation of drivers shows that several factors, such as knowing the difference between a watch and a warning, awareness of safe cover, receipt of warnings through natural environmental cues and the level of education, trigger evacuation actions in avoiding a tornado threat. 相似文献
16.
17.
The Department of Housing and Urban Development (HUD) and the state of Florida implemented new wind load and tie-down regulations
for manufactured homes following Hurricane Andrew. This article examines the effect of the new regulations on the likelihood
that occupants of mobile homes would survive a tornado. On February 2, 2007, three tornadoes struck central Florida, resulting
in 21 deaths in Lake County, all in manufactured homes. The deaths occurred almost exclusively in homes rated as leveled by
the county tax appraiser. Manufactured homes built to the new regulations, however, were significantly less likely to be leveled.
Regression analysis finds that manufactured homes built to the post-Andrew requirements were 79% less likely to be leveled
than homes built prior to the HUD Code in 1976, and 68% less likely to be leveled than homes built after 1976 but before the
1994 wind load regulations. Construction of all manufactured homes in the tornado paths to the wind load and tie-down requirements
could have reduced fatalities by 70%.
相似文献
| Daniel Sutter (Corresponding author)Email: |
18.
Pauline L. Smedley 《Journal of African Earth Sciences》1996,22(4):459-470
Arsenic concentrations in groundwaters from two areas in Ghana, the Obuasi area in the Ashanti region and the Bolgatanga area of the Upper East region vary from <1–64 μg 1−1 and <1–141 μg 1−1, respectively. Sulphide minerals such as arsenopyrite and pyrite are present in the Birimian basement rocks of both areas and these form the dominant As sources. The basement aquifer is overlain by a variable thickness (ranging from <10 m to >40 m) of weathered regolith and lateritic soil. Arsenic concentrations are low in the shallowest groundwaters, but increase at greater depths (40–70 m below ground level in Obuasi and 20–40 m in Bolgatanga). At depths greater than this, total As concentrations are relatively low. The lateral and vertical variations in dissolved As concentrations are controlled by ambient pH and redox conditions and by the relative influences of sulphide oxidation and sorption. In the weathered regolith and lateritic soils, oxidation has been extensive. Shallow groundwaters are oxidizing and acidic. Under these conditions, As is readily oxidized to As(V) and may precipitate as ferric arsenate or be sorbed onto ferric hydroxide surfaces. At greater depth, groundwaters have longer contact times with the aquifer minerals and pH values are therefore higher (>6.0 in Obuasi and >6.5 in Bolgatanga). The oxidation of sulphide minerals may proceed, but dissolved O is consumed during the process and mildly reducing conditions (Eh 200–300 mV) result. Sorption of As onto ferric hydroxide minerals is less favoured under such pH and redox conditions and the element is relatively mobile. At the greatest abstraction depths, groundwaters are more reducing (Eh ≤200 mV; dissolved O <0.1 mg 1−1) and few electron acceptors are available in the system to drive sulphide oxidation. Dissolved As concentrations therefore remain relatively low. The mildly reducing groundwaters in the sulphide-bearing basement aquifer are therefore of the poorest potable quality with respect to dissolved As concentrations. 相似文献
19.
The scarcity of animal products negatively influences nutrition in tropical inland areas, which lack large rivers. Consuming cured marine fish mitigates this deficiency. In Panama, trading cured fish from coastal to inland sites is documented ethnohistorically and can be inferred from the current archaeozoological record. Very large numbers of marine fish remains have been recovered at pre-Columbian sites located on and around Parita Bay, a mangrove-fringed estuary on the central Pacific coast. At Sitio Sierra, a farming village 12 km inland from the active marine shore, more than 70% of fish remains deposited between ca. 1800 and 1500 uncalibrated radiocarbon years BP proved to be of marine origin. Two small rock-shelters located downriver from Sitio Sierra and now 2.6 km from the marine shore (Vampiros-1 and Vampiros-2) show evidence for having been used intensively for fishing and preparing fish between ca. 2200 and 1900 BP. A prior model based on air photograph interpretation and sedimentological analyses of marine and terrigenous sediments suggest that these shelters would have been on or very near the active marine shore at this time. A much earlier occupation at Vampiros-1 dating to ca. 11,500–7700 BP corresponds to pre-agricultural (Paleoindian) and early agricultural (Early Preceramic) people who camped occasionally in this shelter when the transgressing ocean was in the process of flooding Parita Bay. No shell or bone was recovered in this earlier cultural component. In the more recent (2200–1900 BP), component abundant remains of marine mollusks and crustaceans and vertebrate bones (mostly fish) are in excellent condition. A synopsis of the geological and cultural history of the Vampiros shelters is followed by preliminary observations on the relationship between pre-Columbian human activities and these sites’ formation processes, soil chemistry, bone integrity and animal species. Evidence is accruing for human impacts on fish skeletons resulting from the in situ preparation of fish (i.e., gutting, cutting and smoking) providing the opportunity to compare our archaeofaunal data with the results of Irit Zohar's ethno-archeological research, which identified how preparing fish for salting and sun-drying at present-day Panamanian fishing villages around Parita Bay affects the fish skeleton physically and proportionally. There is a strong possibility that the Vampiros shelters were used to provision inland sites like Sitio Sierra with inshore marine fish although we cannot yet ascertain the means by which coastal foodstuffs may have arrived at the latter site. 相似文献
20.
《地学前缘(英文版)》2019,10(6):2281-2285
A rare occurrence of a microspherule has been found in the infratrappean sediments, encountered below 338 m thick Deccan volcanic cover in KLR-1 scientific borehole, drilled in the epicentral zone of the 1993 Killari earthquake (Maharashtra, India). Palynological studies of the sediments indicate their age as Early Permian (Asselian, 298–295 Ma) for deposition. Transmission electron microscope studies reveal that the spherule from the infratrappeans, is having a similar composition to that of the Neoarchean amphibolite to granulite facies mid crustal basement. The spherule is non-spherical in nature, containing mostly FeO (10.70 ± 0.20 wt.%), CaO (13.8 ± 0.5 wt.%), Al2O3 (7.78 ± 0.30 wt.%), MgO (6.47 ± 0.3 wt.%), SiO2 (47.46 ± 0.50 wt.%), TiO2 (2.47 ± 0.3 wt.%), K2O (1.89 ± 0.20 wt.%), and Cl (0.33 ± 0.05 wt.%). Since the Fe composition of the spherule is almost same as the basement rock (10.5 wt.%), and the chlorine content is also in the same range as the basement (0.04–0.24 wt.%), it would suggest possibility of an extraterrestrial impact over the Indian terrain during the erstwhile Gondwana sedimentation period that may be associated with the Permian–Triassic mass extinction, the most severe one in the Earth's history. 相似文献