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1.

This paper examines historical and spatial trends in hazardous materials transportation spills from 1971 to 1991. While the number of spills Inc.reased steadily during the 1970s, peaking in 1978–1979, there has been a decline in frequency sInc.e then largely due to modifications in reporting. Monetary damages have the opposite temporal pattern, with major Inc.reases recorded from 1982 onward. Death and injury statistics are more variable. Spatially, accidents are more prevalent in the Rust Belt extending from the Northeast corridor westward to the Great Lakes states, as well as in the Southeast. The greatest potential risk to the public is found in smaller, more densely populated industrial states such as New Jersey, Delaware, and Maryland. The spatial distribution, however, has not changed. Potential risk sources (e.g., chemical industry, number of hazardous waste facilities, number of railroad miles) are the best predictors of hazmat Inc.ident frequency. Mitigation efforts (statewide regulatory and/or management policies) also help explain the variability in hazmat Inc.idents.  相似文献   

2.
This study examines the spatial distribution and impact of nonroutine accidental releases of hazardous materials relative to the demographic composition of residents in nearby communities. First, atmospheric dispersion modeling methods are used to delineate the impact zones of worst‐case accidents in two New York counties over the last ten years. Next, using accidental reports for 1997, GIS and statistical operations are used at the census tract level of the two counties to determine whether these incidents disproportionately affected disadvantaged neighborhoods. The results suggest that the areas of high‐impact from accidental releases of hazardous materials are best characterized by a large proportion of families below the poverty line, Hispanics, and other minorities.  相似文献   

3.
The recent development of intermodal transportation and the relaxation of U.S. transport regulations have encouraged ocean carriers to rationalize their port schedules. Container shipping is therefore believed to concentrate shipping at a few large ports. Port traffic analysis, using the Lorenz Curve and Gini Coefficient, reveals, nevertheless, that the structure of the U.S. port system is actually becoming less concentrated. The challenge of secondary ports and changes in the transportation system explain this deconcentration.  相似文献   

4.
The geological coal resource of the U.S. is abundant and proved coal reserves are listed as the world’s largest. However, the reserves are unevenly distributed and located in a small number of states, giving them major influence over future production. A long history of coal mining provides detailed time series of production and reserve estimates, which can be used to identify historical trends. In reviewing the historical evolution of coal reserves, one can state that the trend here does not point toward any major increases in available recoverable reserves; rather the opposite is true due to restrictions and increased focus on environmental impacts from coal extraction. Future coal production will not be entirely determined by what is geologically available, but rather by the fraction of that amount that is practically recoverable. Consequently, the historical trend toward reduced recoverable amounts is likely to continue into the future, with even stricter regulations imposed by increased environmental concern. Long-term outlooks can be created in many ways, but ultimately the production must be limited by recoverable volumes since coal is a finite resource. The geologic amounts of coal are of much less importance to future production than the practically recoverable volumes. The geological coal supply might be vast, but the important question is how large the share that can be extracted under present restrictions are and how those restrictions will develop in the future. Production limitations might therefore appear much sooner than previously expected.  相似文献   

5.
基于城镇化发展趋势的中国交通网战略布局   总被引:1,自引:1,他引:1  
顾朝林  曹根榕 《地理科学》2019,39(6):865-873
以世界城市化新趋势和日本高速交通网与京阪都市圈联结带建设为参照系,分析了中国城镇化和城镇体系变化新趋势,重点论述了在未来一段时间内中国面向集聚性发展的交通基础设施战略布局问题。世界城市化正表现为3个特征,它们是:全球城市和全球城市-区域发展,都市圈再繁荣,城市巨型化和巨型区出现。日本三大都市圈呈现两极分化发展,在围绕产业发展实施东京首都圈功能重组的同时,通过编制和实施新的国土发展计划,集中建设京阪都市圈联结带世界超级巨型区。2018年中国人口迈过峰值进入下降通道,然而国家城镇化进程还处在加速期,未来国家城镇体系将从现在的“三纵两横”发展为“四纵五横”发展轴。从整体上看,在未来一段时间内,尽管与之配套的基础设施需求进入平台阶段,但在国家战略地带和潜力增长区以及由于新技术发展还会让以大交通为主的基础设施建设异彩纷呈。在未来一段时间,首先国家战略地带交通网需要加密布局,例如发展长江经济带大通道、长江三角洲一体化高质量发展区扇形网、粤港澳大湾区陆上通道、环首都京津冀城市群交通网;其次需要超前规划布局无人驾驶高速公路,如上海-苏州无人驾驶高速公路、粤港澳大湾区内地无人驾驶高速公路和北京冬奥会无人驾驶高速公路;同时,重视补齐交通基础设施拉动潜力增长区发展,尤其应关注东北地区东、西高速通道、山东外向高速交通互联互通和东北-山东互联互通。此外,乌鲁木齐-喀什、银川-兰州-西宁、西宁-成都、重庆-贵阳-南宁-钦州、成都-拉萨、昆明-保山、银川-西安-武汉-南昌-福州-台北、合肥-南昌-赣州-广州等重要交通线规划布局也非常重要。  相似文献   

6.
We study hurricane risk on the U.S. Gulf Coast during 1950‐2005, estimating the wind damage and storm surge from every hurricane in this extended period. Wind damage is estimated from the known path and wind speeds of individual storms and calibrated to fit actual damage reports for a sample of Gulf Coast storms. Storm surge is estimated using the SLOSH model developed by NOAA. These models provide the first comprehensive overview of the hurricane storm hazard as it has been experienced over a fifty‐six‐year period. We link the estimated damage with information on the population and specific socio‐demographic components of the population (by age, race, and poverty status). Results show that white, young adult, and nonpoor populations have shifted over time away from zones with higher risk of wind damage, while more vulnerable population groups–the elderly, African Americans, and poor—have moved in the opposite direction. All groups have moved away from areas with high risk of storm surge since 1970. But in this case, perhaps because living near the water is still perceived as an amenity, those at highest risk are whites, elderly, and nonpoor households. Here exposure represents a trade‐off between the risk and the amenity.  相似文献   

7.
Geography is again becoming an integral part of the premier natural‐science agency of the federal government. Geographic research emphasizes the surface of the earth, a portion of the earth system that the U.S. Geological Survey (USGS) defines as the “critical zone.” Although geography was part of the USGS from the creation of the agency, in recent years geography in the agency has largely been limited to topographic mapping. Recently, the USGS and an advisory committee of the National Research Council (NRC) reviewed the role of geography at the Survey. The committee's report, along with ongoing decision‐making in the federal government, is likely to reshape geography in the USGS. The newly defined USGS has a regional structure and four disciplines: geology, hydrology, biology, and geography. The NRC report emphasizes the need for the creation of a spatial database called the National Map to replace the existing series of paper topographic maps. The report also outlines the need for geographic research in geographic information science (GIScience), nature‐society connections, and bridging of science to decision‐making. The NRC report has been briefed throughout the USGS, in the federal executive branch, and in Congress. The changing role for geography in the USGS requires change in the agency culture, revised budgetary decisions, and the establishment of a long‐term core agenda for research. Academic geographers will need to prepare a new generation of geographers for participation in the USGS and similar agencies.  相似文献   

8.
Abstract

Seven hypotheses relating to change in metropolitan areas in the decade 1960-70 are developed from literature pertaining to the preceding decade. Analysis indicates that most of the trends apparent in the 1950's have continued in the 1960's, including racial polarization, the effects of age and location of SMSA's, the uniqueness of the South, and rapid growth in the Southeast and West. Several hypotheses were rejected: (1) black suburban populations remained constant, (2) suburbs in the South are losing nonwhites, and (3) SMSA's in the South decentralize more slowly than elsewhere. The influences of annexation, migration, and natural population increase on metropolitan change are briefly discussed.  相似文献   

9.
Religion continues to play an important role in the public and private lives of Americans. Therefore, a reexamination of U.S. religious regions is necessary in light of the rapid demographic changes that have occurred in the past few decades. This article presents a new regionalization of religion in the United States for 1980 and 2000, produced using multivariate cluster analysis. Comparing this new regionalization with earlier attempts, it demonstrates that religious regions continue to exist today and have undergone various levels of stability and change. Furthermore, religious regions continue to be relevant because they provide scholars with a method for identifying and characterizing the societal context in which individual religious communities function.  相似文献   

10.
Emerging statistical techniques, combined with the increasing accessibility of primary social survey data, can provide policy-relevant tools for understanding how perceptions and behaviors vary geographically. Planning for natural disasters requires local data, yet data on topics such as household preparedness behaviors are often unavailable at the appropriate spatial resolution. This article presents new nationwide estimates of one element of household preparedness—having supplies in the home to use in case of a disaster—across all states and metropolitan areas in the United States. Estimates are based on a 2015 national survey combined with multilevel regression and poststratification (MRP), a statistical technique to develop subnational estimates from national data sets. The model uses sociodemographic and geographic predictors informed by prior research. Estimates were externally validated against independent surveys, including data from the 2013 American Housing Survey. Comparing the estimates against historical disaster losses demonstrates broad variation in preparedness even among places with historically high rates of death and injury from natural disasters and allows identification of high-risk places with high disaster losses and low preparedness according to this survey item. Leveraging large survey data sets in combination with MRP can be an effective tool for researchers and decision makers to understand geographic variation in perceptions and behaviors at subnational scales.  相似文献   

11.

Edward Jarvis in 1850 first demonstrated that admission rates to mental hospitals decrease with increasing residential distance, a relationship known today as “Jarvis's Law.” His original data are presented, mapped, and examined by regression analysis to better understand spatial and temporal patterns of mid-19th century mental hospital utilization. Distance substantially affected admission rates to a radius of about 60 miles from the institution in Massachusetts; and there was strong distance decay in the other states examined. For all twelve states, there was a positive association between age of the hospitals and admission rates, which also decreased with increasing residential distance.  相似文献   

12.
13.
博斯腾湖向塔里木河生态输水效果及风险   总被引:6,自引:5,他引:6  
左其亭 《地理科学》2006,26(5):564-568
为了挽救濒临毁灭的塔里木河下游生态环境,中国政府2000~2003年实施5次向塔里木河下游生态应急输水,结束塔里木河下游300 km河道近30年的断流历史。文章基于大量数据资料,简单介绍塔里木河断流过程;再分析近期博斯腾湖向塔里木河下游输水效果;最后从博斯腾湖来水水文特性分析、博斯腾湖调节计算和输水风险分析等方面,阐述博斯腾湖向塔里木河下游输水的风险及控制措施。  相似文献   

14.
What is a hilly city, and which cities are hilliest? This study outlines a basket of methods for quantifying the differential hilliness of U.S. cities. We rank the 100 largest cities in the contiguous United States, using a selection of eight methods to evaluate their comparative hilliness. We then reflect on how four key “modes of encounter” with terrain shape human perceptions of urban hilliness: visual, pedestrian, automotive, and imagined/conceptual. Varying priorities among these different modes of encounter shape which of our indices may best correlate with lay understandings of urban hilliness or particular policy problems. We conclude with implications of this work for contemporary geographic scholarship and suggestions for further research, particularly with regard to the political and economic effects of hilliness.  相似文献   

15.
This work investigates how potential changes in trade patterns resulting from increased economic integration in the Asia-Pacific region may affect the risk for nonindigenous species spread to the United States. We construct an invasion risk index utilizing the results from a global economic modeling framework in tandem with data for climate similarities between trade partners. The index is based on risk of introduction, determined by changes in trade, and risk of establishment, given by terrestrial and marine climate similarities between countries. The results indicate that Japan may be the riskiest trade partner for the United States in the Asia-Pacific region from a nonindigenous species perspective. This is driven by large expected changes in trade and high environmental similarity between the two countries. This research provides the basis of a risk assessment prediction system to examine the effects of changes in trade on nonindigenous species risk, an important, novel contribution to the trade policy literature.  相似文献   

16.
姜辉 《地理科学》2020,40(10):1618-1626
从总贸易、出口、进口、外资和人员5个视角构建对美风险系数,测度和比较各省区市对美外贸风险的地理差异。结果表明:上海、浙江和福建与美国的进出口贸易规模最大,对美国市场的依赖程度最高,面临的综合外贸风险最大;河南尤其需要防范对美国的出口风险;海南、新疆、天津和西藏等需要加强从美国进口的风险管理;重庆除了需要防范对美出口风险外,还因为实际利用美资最多且依赖程度最大,亟需加强外资风险管理。宁夏和山西虽然从美国的引资规模不大,但是对美资的依赖程度最高,亟需提升外资多元化水平。从人员跨境流动风险来看,上海、北京和浙江面临的风险最大。中国各省区市在应对美国出口管制时应该加强外贸风险的识别和管理,针对不同的风险采取差别化的防范和化解措施。  相似文献   

17.
The internationalization of the world's producer services has included the steady expansion of legal services across national borders. This article opens with an examination of the supply and demand factors that have driven this process, including the strategies and problems faced by law firms that operate internationally. It then offers an empirical examination of the distribution of overseas legal services offices of the 700 largest U.S. law firms, including their foreign markets and headquarters cities.  相似文献   

18.
The literature on shrinking cities has significantly grown in recent years. Little work, however, has been done toward the development of a shrinking city typology, which could help inform solutions and strategies to address problems associated with population loss. With a focus on central cities, this article identifies 367 shrinking cities within the United States and categorizes them using a geographic information system to identify seven types of shrinking cities in the United States: (1) large shrinking central cities, (2) inner-ring suburbs of shrinking central cities, (3) outer-ring suburbs of shrinking central cities, (4) inner-ring suburbs of growing central cities, (5) outer-ring suburbs of growing central cities, (6) small shrinking central cities in small Metropolitan Statistical Areas, and (7) small shrinking cities in small Micropolitan Statistical Areas. The empirically generated clusters, combined with associated social and demographic information, identify separate but sometimes interrelated shrinking city types and provide a new perspective for addressing the problems faced by U.S. shrinking cities. Key Words: population decline, shrinking cities, typology, urban population.  相似文献   

19.
Bedrock forms of etch origin result from the interaction of groundwaters and bedrock at the weathering front at the base of the regolith. They are significant for general theories of landscape and landform genesis because they are azonal with respect both to climate and lithology. Two stages of etch form development are recognized: one involves weathering and the formation of a regolith; the second consists of stripping of the regolith and the exposure of the bedrock forms. Although etch forms have been recognized for some two centuries, the concept of etching as a process of landform development has been neglected, particularly in North America.  相似文献   

20.
The U.S. Geological Survey periodically makes appraisals of the oil and gas resources of the Nation. In its 1995 National Assessment the onshore areas and adjoining State waters of the Nation were assessed. As part of the 1995 National Assessment, 274 conventional oil plays and 239 conventional nonassociated-gas plays were assessed. The two datasets of estimates studied herein are the following: (1) the mean, undiscovered, technically recoverable oil resources estimated for each of the 274 conventional oil plays, and (2) the mean, undiscovered, technically recoverable gas resources estimated for each of the 239 conventional nonassociatedgas plays. It was found that the two populations of petroleum estimates are both distributed approximately as lognormal distributions. Fractal lognormal percentage theory is developed and applied to the two populations of petroleum estimates. In both cases the theoretical percentages of total resources using the lognormal distribution are extremely close to the empirical percentages from the oil and nonassociated-gas data. For example, 20% of the 274 oil plays account for 73.05% of the total oil resources of the plays if the lognormal distribution is used, or for 75.52% if the data is used; 20% of the 239 nonassociated-gas plays account for 76.32% of the total nonassociated-gas resources of the plays if the lognormal distribution is used, or for 78.87% if the data is used  相似文献   

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