共查询到20条相似文献，搜索用时 31 毫秒
1.
为研究不利天气事件对冬季旅游的影响,以吉林省为研究区,针对冬季旅游中不利天气发生概率进行分析,选取大风（风速＞5 m/s）、极端低温（≤?16℃）和降水日数3种不利天气事件,通过优化吉林省各气象站点的多元Copula函数,分析了3种不利天气群发特征及其对吉林省冬季旅游造成的影响。研究发现,Survival Joe (SJ)、Clayton、Farlie-Gumbel-Morgenstern (FGM) 3个属函数适合构建R-Vine Copula并用于分析不利气象条件对吉林省冬季旅游影响。从日气象数据分析发现,吉林省冬季单一不利气象条件的发生频率在0.15~0.30之间,而同时发生两种不利气象条件的频率在0.01~0.04之间,西部地区的不利气象条件发生频率高于中东部地区。在吉林省冬季多种不利气象条件群发的耦合分析中,白城、松原、四平地区不利气象事件发生联合概率较高,但是从冬季冰雪旅游经济损失上,长春、延边、松原、白城和吉林市潜在损失较大。这对于分析气象条件对冰雪旅游影响作用机制,吉林省冰雪旅游出行保险制定,冰雪旅游灾害防控和调整冰雪旅游空间规划具有重要指导意义。 相似文献
2.
Jill S.M. Coleman 《The Professional geographer》2013,65(2):190-206
Although much research has been done linking meteorological variables individually with various aspects of human health, few studies have considered the collective impact of weather. This study examines the relationship among ten synoptic-scale weather patterns and daily cause-specific human mortality rates for metropolitan areas in the central United States during the 1978 to 1998 autumn and spring seasons. The results show that distinctive changes in mortality rates are often associated with one or two of the more moderate synoptic types, displaying notable spatial and temporal variability. The occurrence of the Eastern Zonal (EZ) pattern during spring and the East Coast Trough (ECT) pattern during autumn seems to invoke the most significant increased mortality response across all causes of death and metropolitan statistical areas. For the EZ and ECT types, the largest adverse response occurs for locations influenced by cold, anticyclonic situations and atmospheric stability. 相似文献
3.
ALAN P. MARCUS 《Geographical review》2009,99(4):481-498
ABSTRACT. In the late 1980s more than 1 million Brazilians left Brazil without returning. Today an estimated 2 million Brazilians live abroad, 1.2 million of them in the United States. In this article I show that Brazilians migrate for a variety of reasons, including the geographical imagination. Why are so many Brazilians leaving for the United States? What are their geographical imaginations, and how are they described in their migration process? Using primary and secondary data and multiple methods, I address these questions by providing insights into Brazilian migrants' place perceptions, experiences, and reasons for migrating, focusing on the geographical imagination. Those migrants who end up returning to Brazil are more likely to cite financial and curiosity reasons for having migrated. A web of transnational religious and social networks sustains those immigrants who remain in the United States. Reasons for migrating are not economic alone; rather, they are based on interrelated and complex factors that range from adventure to curiosity, the cultural influence of the United States, family members, education, and escape. 相似文献
4.
CLIMATOLOGICAL CLASSIFICATION OF SEVERE WIND-DRIVEN RAIN EVENTS AFFECTING THE SOUTHERN UNITED STATES
This paper follows recent studies of wind-driven rain (WDR), and statistically defines a “severe” WDR event. The research suggests a classification for severe WDR events by association with larger-scale weather systems. The study incorporates data for the period 1971 to 1995 and, from these data, the analysis reveals that severe WDR events are confined mainly to the southern United States and occur most frequently in the cold and transition seasons. Extratropical cyclones are the most common synoptic-scale weather systems associated with severe WDR events. Extratropical cyclones originating in three areas accounted for more than 70 percent of the severe events in the study. The cyclone types are referred to as Colorado Lows (CLs), Gulf Lows (GLs), and Texas Lows (TLs). The attendant synoptic-scale conditions of cyclones that produced severe WDR events differ significantly from extratropical cyclones originating in similar areas but not producing severe events. Key differences between the two cyclone populations are the cyclone track trajectories and the low and midlevel synoptic environments promoting cyclone intensification. [Key words: wind-driven rain (WDR), synoptic climatology, extratropical cyclones, United States.] 相似文献
5.
Andrew J. Fultz 《自然地理学》2016,37(5):291-312
General, or private and non-commercial, aviation accidents produce more fatalities than any other aviation category within the United States. Despite advances in scientific understanding and technology since the early 1900s, weather causes concern for aviation safety, and little is known about the characteristics of fatal weather-related general aviation accidents. We provide a comprehensive spatiotemporal analysis of fatal weather-related general aviation accidents from 1982 through 2013 using data culled from the United States National Transportation Safety Board (NTSB). Weather was a cause or contributing factor in 35% of fatal general aviation accidents, of which 60% occurred while instrument meteorological conditions were present. Fatal weather-related general aviation accidents occur most frequently between October and April, on weekends, in early morning and evening periods, and along the West Coast, Colorado Rockies, Appalachian Mountains, and the Northeast. There has been a long-term reduction in weather-related general aviation accidents and fatalities since the 1980s; nonetheless, these accidents are still responsible for nearly 100 fatalities/year in the United States. This study provides pilots, academics, the Federal Aviation Administration, the NTSB, and other aviation organizations with information to advance mitigation efforts aimed at reducing future aviation-related accidents in the United States. 相似文献
6.
JOHN FRASER HART 《Geographical review》2001,91(3):525-543
ABSTRACT. The census concept of total cropland is a better measure of effective agricultural land than is total farmland, which includes extensive areas of woodland owned by farmers. The cropland area of the United States dropped from 478 million acres in 1949 to 431 million acres in 1997, for a net loss of less than 1 million acres, or roughly one‐fifth of 1 percent, per year. In the midwestern agricultural heartland most counties changed less than 5 percent in the half‐century, and more counties gained than lost. The West was a crazy quilt of change, and in the East most counties lost more than 10 percent. Major metropolitan counties lost a few percentage points more than did adjacent areas, but at a lower rate per capita than the nation as a whole. Most of the loss of cropland was in marginal agricultural counties with soils of low inherent fertility and topography unsuited to modern farm machinery. The loss of cropland to suburban encroachment may be cause for intense local concern, but attempts to thwart development cannot be justified on grounds of a net national loss of good cropland. 相似文献
7.
Kathleen R. Weimer Carson J. Q. Farmer Colleen E. Reid 《The Professional geographer》2013,65(4):762-769
The overuse of cesarean sections (C-sections) in the United States is a contested issue. The rate of C-section births in 2015 at 32 percent was over double the World Health Organization recommendation of 10 to 15 percent. We employed spatial statistical methods and data visualization techniques to assess the temporal and spatial trends in C-section rates by county across the United States. Although the national rate of C-section remained stable at the beginning and end of this study period, an increase in rates from 1997 to 2009 was reflected simultaneously in national, state, and individual county rates. Local indicators of spatial dependence did not show spatial clustering as being connected to, or driving, the change, yet the visualization methods used here show details on individual county deviance from local temporal trends. By highlighting counties that do not follow the trends of their neighbors, we identify exceptional locations that could help further the study of the determinants of changing C-section rates in the United States. Key Words: cesarean sections, exploratory spatial data analysis, medical geography, spatial statistics. 相似文献
8.
Maria Castro César De Santos-Berbel 《International journal of geographical information science》2013,27(12):2061-2074
Because of the high number of crashes occurring on highways, it is necessary to intensify the search for new tools that help in understanding their causes. This research explores the use of a geographic information system (GIS) for an integrated analysis, taking into account two accident-related factors: design consistency (DC) (based on vehicle speed) and available sight distance (ASD) (based on visibility). Both factors require specific GIS software add-ins, which are explained. Digital terrain models (DTMs), vehicle paths, road centerlines, a speed prediction model, and crash data are integrated in the GIS. The usefulness of this approach has been assessed through a study of more than 500 crashes. From a regularly spaced grid, the terrain (bare ground) has been modeled through a triangulated irregular network (TIN). The length of the roads analyzed is greater than 100 km. Results have shown that DC and ASD could be related to crashes in approximately 4% of cases. In order to illustrate the potential of GIS, two crashes are fully analyzed: a car rollover after running off road on the right side and a rear-end collision of two moving vehicles. Although this procedure uses two software add-ins that are available only for ArcGIS, the study gives a practical demonstration of the suitability of GIS for conducting integrated studies of road safety. 相似文献
9.
Vehicle‐related hyperthermia is an unfortunate tragedy that leads to the accidental deaths of children each year. This research utilizes the most extensive dataset of child vehicle‐related hyperthermia deaths in the United States, including 414 deaths between 1998 and 2008. Deaths follow a seasonal pattern, with a peak in July and no deaths in December or January. Also, deaths occurred over a wide range of temperature and radiation levels and across virtually all regions, although most of them took place across the southern United States. In particular, the Phoenix, Houston, Dallas, and Las Vegas metropolitan areas had the greatest number of deaths. We utilize our vehicle hyperthermia index (vhi ) to compare expected deaths versus actual deaths in a metropolitan area, based on the number of children in the area who are under the age of five and on the frequency of hot days in the area. The vhi indicates that the Memphis, West Palm Beach‐Boca Raton, and Las Vegas metropolitan areas are the most dangerous places for vehicle‐related hyperthermia. We conclude by discussing several recommendations with public health policy implications. 相似文献
10.
J.R. Tarrant 《Applied geography (Sevenoaks, England)》1981,1(4):273-286
The grain embargo, introduced by the United States on the USSR after the invasion of Afghanistan, reduced Russian grain supplies by about six million tonnes in 1979/80. This resulted in some reduction in meat output, but the effects were not as great as had been anticipated as the Russians were able to find alternative sources of supply for much of the embargoed grain. The embargo resulted in the United States' grain prices falling, although this was partly prevented by the United States government purchasing grain destined for the Russian market. Costs to the United States government and taxpayer were kept down by the government reselling this grain for export during the summer of 1980. Despite some shuffling of markets between suppliers, the grain market has more or less returned to normal, helped by strong world demand for grain. 相似文献
11.
Steven M. Quiring 《The Professional geographer》2007,59(3):357-364
A proportional shift in where geographer‐climatologists publish has occurred in recent decades. More than 1,500 journal articles published by members of the Association of American Geographers' Climate Specialty Group (CSG) in the period 1989–2005 were examined to determine where geographer‐climatologists are publishing. The analysis showed that members of the CSG cumulatively published at least ten articles in thirty‐seven different journals. No single journal accounted for more than 7 percent of the articles published. Although the absolute number of articles has remained relatively static, geographer‐climatologists published 21 percent of their articles in geography journals in 1989–1997, but only 11 percent in 1998–2005. These publication trends are likely to continue and may influence the status and prestige of geography journals and the discipline of geography. 相似文献
12.
《The Journal of geography》2012,111(9):38-43
Abstract Although blacks constitute the largest ethnic minority in the United States, historically they have either been largely omitted from geographic literature or else portrayed in less than a humanistic manner. However, beginning about 1965 a change took place in geography regarding its interest and treatment of black Americans. Within the last eight or nine years the geography of black America has blossomed into a full-fledged subfield of geography. In all, over 200 theses, dissertations and published works have been produced by geographers during this period. Moreover, a sharp shift in subject emphasis has occurred. Prior to 1965, what little geographic literature there was dealt mostly with rural or regional studies. Now the emphasis is, at long last, upon urban black American where over eighty percent of blacks reside. 相似文献
13.
Common perception is that tornadoes travel in paths from the southwest quadrant of directions toward the northeast. This study examines path directions for 6,194 tornadoes that occurred in the eastern two‐thirds of the United States during the twenty‐three‐year period 1980–2002. At the national scale, nearly 70 percent of tornadoes included in the study propagated from the west, west‐southwest, and southwest, with west‐southwest being the highest frequency origin direction. Nevertheless, distinct seasonal and regional variations were found. In central and northern areas of the country, a more westerly or northwesterly path origin prevails during late spring and summer. The midtropospheric flow, convective typology, and synoptic patterns of tornado outbreaks are thought to contribute to the distributions observed in the climatology. 相似文献
14.
Motorists are vulnerable to extreme weather events, which are likely to be exacerbated by climate change throughout the world. Traffic accidents are conceptualized in this article as the result of a systemic failure that includes human, vehicular, and environmental factors. The snowstorm and concurrent accidents that occurred in the Northeastern United States on 26 January 2011 are used as a case study. Traffic accident data for Fairfax County, Virginia, are supplemented with Doppler radar and additional weather data to characterize the spatiotemporal patterns of the accidents resulting from this major snowstorm event. A kernel density smoothing method is implemented to identify and predict patterns of accident locations within this urban area over time. The predictive capability of this model increases over time with increasing accidents. Models such as these can be used by emergency responders to identify, plan for, and mitigate areas that are more susceptible to increased risk resulting from extreme weather events. 相似文献
15.
John Agnew 《Geographical review》2019,109(4):507-526
The year 2018 saw a moral panic in the United States in the media and among many citizens over the treatment of refugees/asylees at the U.S. southern border, particularly the separation and detention of children apart from their parents. This happened in the context of a period in U.S. political history in which “immigration,” without much discernment about different types of immigration, was central to political discourse. In fact, in terms of numbers, there was no immigration crisis at the border. Undocumented migration from Mexico across the southern border of the United States has been in decline for many years, and the irregular movement of people from El Salvador, Guatemala, and Honduras is currently small by historical standards. The only crisis, to which the U.S. panic was a response, has been a human rights crisis. Families and children seeking asylum from horrendous civil‐rights conditions in their countries of origin were criminalized and denied their right to asylum hearings. The panic points both to the extreme politicization of immigration in the United States, particularly since Donald Trump's entry into national politics in 2015, and to popular confusion over categorizing different types of immigrants. But it also raises questions about the nature of the U.S. southern border in relation to the United States’ place in the world. Rather than thinking about the United States as simply the rich destination country of unfortunate people coming from poor origin countries, the refugee panic of 2018 brings into the focus the fact that the United States itself is complicit in the conditions in those countries that produce so many refugees in the first place. 相似文献
16.
Katharine Guiles Ellis Henry T. Mullins William P. Patterson 《Journal of Paleolimnology》2004,31(3):343-361
Climate change in the northeastern United States has been inferred for the last deglaciation to middle Holocene (∼16,600 to 6000 calendar years ago) using multi-proxy data (total organic matter, total carbonate content, δ18 O calcite and δ13 C calcite) from a 5 m long sediment core from Seneca Lake, New York. Much of the regional postglacial warming occurred during the well-known Bolling and Allerod warm periods (∼14.5 to 13.0 ka), but climate amelioration in the northeastern United States preceded that in Greenland by ∼2000 years. An Oldest Dryas climate event (∼15.1 to 14.7 ka) is recognized in Seneca Lake as is a brief Older Dryas (∼14.1 ka) cold event. This latter cold event correlates with the regional expansion of glacial Lake Iroquois and global meltwater pulse IA. An increase in winter precipitation and a shorter growing season likely characterized the northeastern United States at this time. The Intra-Allerod Cold Period (∼13.2 ka) is also evident supporting an “Amphi-Atlantic Oscillation” at this time. The well-known Younger Dryas cold interval occurred in the northeastern United States between 12.9 and 11.6 ka, consistent with ice core data from Greenland. In the Seneca Lake record, however, the Younger Dryas appears as an asymmetric event characterized by an abrupt, high-amplitude beginning followed by a more gradual recovery. Compared to European records, the Younger Dryas in the northeastern United States was a relatively low-amplitude event. The largest amplitude and longest duration anomaly in the Seneca Lake record occurs after the Younger Dryas, between ∼11.6 and 10.3 ka. This “post-Younger Dryas climate interval” represents the last deglacial climate event prior to the start of the Holocene in the northeastern United States, but has not been recognized in Greenland or Europe. The early to middle Holocene in the northeastern United States was characterized by low-amplitude climate variability. A general warming trend during the Holocene Hypsithermal peaked at ∼9 ka coincident with maximum summer insolation controlled by orbital parameters. Millennial- to century-scale variability is also evident in the Holocene Seneca Lake record, including the well-known 8.2 ka cold event (as well as events at ∼7.1 and 6.6 ka). Hemispherical cooling during the Holocene Neoglacial in the northeastern United States began ∼5.5 ka in response to decreasing summer insolation. 相似文献
17.
Yuk Yee Yan 《Singapore journal of tropical geography》1997,18(2):210-217
The universal scale of apparent temperature (AT) and clo, a unit measuring the amount of clothing insulation required to maintain comfort, were used to examine the weather stress in Hong Kong. Hourly AT and clo values were computed using hourly air temperature, wind speed, vapour pressure and cloud cover data from 1980 to 1994. Results of both AT and clo reflected highly corresponding changes of thermal stress. It is found that the most stressful time in winter and summer occurred in the early morning and afternoon, and cool weather and tropical ensembles were required to surmount the extreme weather stress respectively. A greater percent of time with severe heat stress than those with extreme cold stress was discovered. These results also indicated that clo is a more informative weather stress index than AT since it provides both the thermal stress and clothing requirements to sustain comfort. 相似文献
18.
Vehicle-related hyperthermia is an unfortunate tragedy that leads to the accidental deaths of children each year. This research utilizes the most extensive dataset of child vehicle-related hyperthermia deaths in the United States, including 414 deaths between 1998 and 2008. Deaths follow a seasonal pattern, with a peak in July and no deaths in December or January. Also, deaths occurred over a wide range of temperature and radiation levels and across virtually all regions, although most of them took place across the southern United States. In particular, the Phoenix, Houston, Dallas, and Las Vegas metropolitan areas had the greatest number of deaths. We utilize our vehicle hyperthermia index (vhi) to compare expected deaths versus actual deaths in a metropolitan area, based on the number of children in the area who are under the age of five and on the frequency of hot days in the area. The vhi indicates that the Memphis, West Palm Beach-Boca Raton, and Las Vegas metropolitan areas are the most dangerous places for vehicle-related hyperthermia. We conclude by discussing several recommendations with public health policy implications. 相似文献
19.
Norah F. Henry 《The Professional geographer》1982,34(1):65-70
The fragmentation of health care services evident in contemporary United States medical care may also be seen in the provision of abortion-facility service, despite recent moves toward comprehensive health care. Abortion facilities in northeastern and southern states appear more likely to provide comprehensive services than do central and western facilities, based upon a survey of facility characteristics for 1978. Abortion cost and number of facilities, a competition variable, aid in discriminating among groups of facilities with service-level differentials. 相似文献
20.
This county-level study examines the locational concentrations of the 1.6 million military retirees in the United States. Maps and multiple regression analysis suggest a strong association between concentrations of military retirees in a county and amenity- and military-related factors. In particular, proximity to a military base, mild winters, and coastal locations attract the military retiree. When counties are grouped by the age of the retirees, the proximity to bases becomes more closely associated with the younger military retirees, while climate and amenity factors are more important for the older retirees. These findings could prove useful in projecting locational preferences of the older more mobile population of the United States. 相似文献