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1.
This essay questions the effectiveness of nuclear winter modeling as a means of impacting nuclear policy and changing public attitudes about nuclear issues. In nuclear winter modeling, humanistic concern over the possibility of global environmental destruction is cloaked in the ostensibly neutral language of science. Nuclear winter modeling attempts to apply rational argument to an issue that is rooted instead in human affect and morality. The implications of this misappropriation are discussed in terms of the dehumanizing nature of the images conjured up by nuclear winter, its attention to the effects of nuclear weapons rather than deeper structural problems, and its political ambiguity as a function of unresolvable uncertainty in model results.  相似文献   

2.
《The Journal of geography》2012,111(4):235-246
Abstract

By the end of this century the Panama Canal will have reached its maximum capacity of 50,000 ship transits a year. If the needs of future inter-oceanic commerce are to be met it is imperative that a new and expanded waterway across the Isthmus of Central America be created. A sea-level type canal would best serve the demands of twenty-first century shipping. Two techniques are feasible for such a project: conventional and nuclear excavation. Each technique boasts of certain advantages over the other, the conventional being safer while the nuclear is faster and cheaper. Five routes have been scrutinized as a potential canal site. Prior to any final determination of either digging procedure or route location, problems such as safety, regional ecology, canal currents, and diplomatic and political agreements must be resolved—with 1985 looming as the latest judicious date to commence excavation.  相似文献   

3.
玉龙雪山冰川稳定同位素分馏冬夏对比   总被引:3,自引:0,他引:3  
1 Introduction Under the dominance of South Asian monsoon, China’s temperate glaciers are distributed on Hengduan Mountains (southeast of Tibetan Plateau), the central part and southern slope of the Himalaya Mountains as well as the central and eastern p…  相似文献   

4.
Abstract

The potentially severe strain that subnormal winter temperatures would impose upon reduced heating fuel supplies prompted publication of a long-range, national, winter weather forecast in November 1973. However, limitation of the art of weather forecasting that stem ultimately from the complex episodic nature of weather behavior diminish the reliability of this outlook. In spite of the complexity encountered along the way, a journey into weather records of the past does reveal some observations about weather activity that are useful in assessing winter temperature prospects. These observations include the characteristic nonuniformity of weather behavior, the existence of long-range and seasonal climatic trends, and the thermal effects of early-season establishment of a heavy snow cover.  相似文献   

5.
Nuclear power plant siting provided the first significant public opportunity to examine nuclear safety and to affect nuclear policy. These discussions were prompted and fueled by perceptions of nuclear risk. Now, as we begin the process of nuclear decommissioning, we are finding that power plant removal—unsiting–is also likely to attract public interest. This paper presents a preliminary survey of how we are likely to react to this emerging theme, applying these findings within a land use context to see if it is likely to produce issues salient to the public. In so doing it also examines how these issues could affect decommissioning timing and type. It suggests that the most likely prospect is that power plants will remain on the landscape long after they are closed.  相似文献   

6.

This paper investigates the determinants of spatial knowledge and how our knowledge of space varies according to geographic location. By using data on U.S. city names recalled at 22 test locations, a multivariate model of the information surface specific to each test location is calibrated. This model links the probability of a city being recalled from memory to its distance from the test site, its population size, its location with respect to other cities, and whether or not it is a state capital. The paper then suggests that these recall data provide information on spatial knowledge surfaces from which large-scale spatial choices, such as migration destinations, are made. Results from the analysis lend further evidence to the idea that spatial knowledge is stored and processed hierarchically and that individuals underrepresent information in large clusters. Consequently, the results have important implications for modeling any spatial behavior based on individuals' spatial information surfaces. In particular, the results cast further doubt on the validity of traditional large-scale spatial choice frameworks and lend support to the competing destinations hypothesis.  相似文献   

7.

The spatial distribution of the alpine permafrost is modelled in the uppermost part of Val de Rechy (Valais Alps, Switzerland) with the use of a geographical information system (GIS). Two empirical-statistical models are compared and their validity tested by a set of bottom temperature of winter snow (BTS) measurements carried out in the field. One model can simulate the spatial distribution of the permafrost facing ground warming consecutive to climatic change. Local/regional maps of simulated permafrost distribution as presented in this paper can be useful in the context of a preventive approach for natural hazards management.  相似文献   

8.

Scale and resolution have long been key issues in geography. The rapid development of analytical cartography, GIS, and remote sensing (the mapping sciences) in the last decade has forced the issues of scale and resolution to be treated formally and better defined. This paper addresses the problem of scale and resolution in geographical studies, with special reference to the mapping sciences. The fractal concept is introduced, and its use in identifying the scale and resolution problem is discussed. The implications of the scale and resolution problem on studies of global change and modeling are also explored.  相似文献   

9.

The southeastern United States, including Florida, has been identified as a region of homogeneous response to the El Niño/Southern Oscillation (ENSO) climatic anomaly, in which mean monthly precipitation and discharge during winter is above or below normal following the onset of the warm (El Niño) or cold (La Niña) phase of ENSO, respectively. However, this understanding of the response is expanded through a study of the effects of the ENSO phenomenon on the probability distributions of mean monthly streamflows of the Santa Fe river. The Santa Fe river basin is situated between one region, which experiences the greatest proportion of annual streamflow during winter, and another where the largest percentage of annual flow occurs during late summer. The basin experiences both winter and summer peaks in precipitation and (subsequent) streamflow and may therefore display responses to ENSO during each season. A two-parameter lognormal distribution is employed to model these streamflows during warm and cold phases of ENSO. Increases in both the mean and the variance detected during warm phase winters are compatible with previous observations. Increases in variance apparent during cold phase summers have not been previously identified. These results, which have considerable bearing upon predictions of high and low flow probabilities during the year, suggest that the response in streamflow is not spatially homogeneous across the state.  相似文献   

10.
1956-2003年拉萨河流域径流变化趋势   总被引:4,自引:1,他引:3  
Taking the Lhasa River Basin above Lhasa hydrological station in Tibetan Plateau as a study area, the characteristics of the annual and monthly mean runoff during 1956-2003 were analyzed, based on the hydro-data of the two hydrological stations (Lhasa and Tanggya) and the meteorological data of the three meteorological stations (Damxung, Lhasa and Tanggya). The trends and the change points of runoff and climate from 1956 to 2003 were detected using the nonparametric Mann-Kendall test and Pettitt-Mann-Whitney change-point statistics. The correlations between runoff and climate change were analyzed using multiple linear regression. The major results could be summarized as follows: (1) The annual mean runoff during the last 50 years is characterized by a great fluctuation and a positive trend with two change points (around 1970 and the early 1980s), after which the runoff tended to increase and was increasing intensively in the last 20 years. Besides, the monthly mean runoff with a positive trend is centralized in winter half-year (November to April) and some other months (May, July and September). (2) The trends of the climate change in the study area are generally consistent with the trend of the runoff, but the leading climate factors which aroused the runoff variation are distinct. Precipitation is the dominant factor influencing the annual and monthly mean runoff in summer half year, while temperature is the primary factor in winter season.  相似文献   

11.
ABSTRACT

Cost surfaces are a crucial aspect of route optimization and least cost path (LCP) calculations and are used in awide range of disciplines including computer science, landscape ecology, and energy-infrastructure modeling. Linear features present akey weakness to traditional routing calculations along cost surfaces because they cannot identify whether moving from acell to its adjacent neighbors constitutes crossing alinear barrier (increased cost) or following acorridor (reduced cost). Following and avoiding linear features can drastically change predicted routes. We introduce an approach to address this adjacency issue using asearch kernel that identifies these critical barriers and corridors. We have built this approach into anew Java-based open-source software package– CostMAP (cost surface multi-layer aggregation program)– which calculates cost surfaces and cost networks using the search kernel. CostMAP allows users to input multiple GIS data layers and to set weights and rules for developing aweighted-cost network. We compare CostMAP performance with traditional cost surface approaches and show significant performance gains– both following corridors and avoiding barriers– by modeling the movement of alarge terrestrial animal– the Baird’s Tapir (Tapirus bairdii)– in amovement ecology framework and by modeling pipeline routing for carbon capture and storage (CCS).  相似文献   

12.
核电工业的发展和布局,与国际气候变化谈判、地缘政治和国家安全、以及国家竞争优势等密切相关,对全球核电工业空间格局演变及国家核电产业竞争力的研究具有重要的理论与实践意义。基于世界34个核电国家和198座核电厂数据,本文首先梳理了世界核电工业的发展阶段和空间布局;进一步运用综合评价指标体系、弦图、网络拓扑关系图,从产业链和贸易网络角度综合评价国家核电产业竞争力,从而对世界核电工业地理格局进行了多维度剖析。结果表明:核电在发达国家能源生产中的比例总体呈下降趋势;核电工业宏观布局现以欧美为主,但亚洲正成为全球核电工业布局的重心区域;全球核电厂微观区位布局主要靠近电力需求集中的人口和经济密集区;国家间核电产业竞争力差异显著,国家地位呈现明显的等级体系和中心-外围结构,地缘邻近性和集团化特征明显,美国、俄罗斯等核电强国居垄断地位。本研究以期为中国核电产业发展提供国际经验借鉴,并从增强核电产业链核心环节竞争力的角度提出建议。  相似文献   

13.
Abstract

Peary caribou is the northernmost designatable unit for caribou species, and its population has declined by about 70% over the last three generations. The Committee on the Status of Endangered Wildlife in Canada identified difficult grazing conditions through the snow cover as being the most significant factor contributing to this decline. This study focuses on a spatially explicit assessment tool using snow model simulations (Swiss SNOWPACK model driven in an off-line mode by spatialized meteorological forcing data generated by the Canadian Regional Climate Model) to characterize snow conditions for Peary caribou grazing in the Canadian Arctic. The life cycle of Peary caribou has been subdivided into three critical periods: summer foraging and fall breeding (July–October), winter foraging (November–March), and spring calving (April–June). Winter snow conditions are analyzed and snow simulations compared to Peary caribou island counts to identify a snow parameter that could potentially act as a proxy for grazing conditions and explain fluctuations in Peary caribou numbers. This analysis concludes that caribou counts are affected by simulated snow density values >300 kg m?3. A software tool mapping possibly favorable and unfavorable grazing conditions based on snow is proposed at a regional scale across the Canadian Arctic Archipelago. Specific output examples are given to show the utility of the tool, mapping pixels with cumulative snow thickness above densities of 300 kg m?3, where cumulative seasonal thicknesses >7000 cm are considered unfavorable.  相似文献   

14.
Intensive grazing in spring–summer has been responsible for environmental degradation of the Gurbantunggut Desert in recent years. The coverage of plants and biological crusts, sand surface stability and physicochemical characteristics of soil on the dune surface were conducted in 2002 (winter grazing) and 2005 (spring–summer grazing). The results showed that over 80% of the total area of the dune surface was covered by well-developed biological crusts and plants in 2002, when the interdune and middle to lower part of dune slopes were stabilized and only the crest had 10–40 m wide mobile belt. Affected by spring–summer grazing in 2005, over 80% of the total cover of biological crust was destructed and the plant coverage only reached 1/5 of that in 2002, especially the ephemeral plant cover had a great change. The value of sand transport potential in 2005 only reached 1/3 of that in 2002, but the total surface activity in 2005 was 1.6 times stronger than that in 2002. Meanwhile the mobile area began to expand from the dune top to the whole dune surface following spring–summer grazing. Compared with 2002, medium sand content of the dune surface soil increased by 13.9%, while that of fine and very fine sands decreased by 7.4% and 8.0% respectively in 2005 and the soil organic matter in 2005 was only about 1/2 of that in 2002. It is obvious that the presence of snow cover and frozen soil in winter could avoid the surface structure destruction in winter, while spring–summer grazing made excessive damage to biologic crusts and ephemeral plants. Spring is the main windy season in Gurbantunggut Desert and therefore intensive activity of dune surface occurred following spring–summer grazing, which led to a great loss of fine sand and organic matter. It can be seen that grazing season have a significant influence on the sustainable development of the desert ecosystem in Northwest China. Foundation: National Basic Research Program of China, No.2009CB421303; National Natural Science Foundation of China, No.40771032; National Science Supporting Program, No.2007BAC17B03 Author: Wang Xueqin (1964–), Ph.D and Associate Professor, specialized in aeolian sand geomorphology, desertification and its control.  相似文献   

15.

The Posets massif is located in the Central Pyrenees and reaches a height of 3363 m a.s.l. at the Posets peak, the second highest massif in the Pyrenees. Geomorphological maps of scales 1:25000 and 1:10000, BTS (bottom temperature of winter snow), ground measurements and snow poles were used to observe the more representative periglacial active landform association, ground thermal regime, the winter snow cover evolution and basal temperatures of snow. The main active periglacial landforms and processes related to the ground thermal regime and snow cover were studied. Mountain permafrost up to 2700 m a.s.l. on northexposed slopes and up to 2900 m a.s.l. on south-exposed slopes were detected. Three permafrost belts were differentiated: sporadic permafrost between 2700 and 2800 m a.s.l. and between 2850 and 3000 m a.s.l., discontinuous permafrost between 2800 and 2950 and between 2950 and 3050, and continuous permafrost up to 2900 m a.s.l. and up to 3050 m a.s.l. on northern and southern slopes, respectively.  相似文献   

16.
Abstract|Gjessing,

Y. T. 1968. On the Relation between the Meteorological Conditions and the Freezing of Lusterfjord. Norsk geogr. Tidsskr. 22, 200–208,

In most cases Lusterfjord freezes over in winter immediately after a period of mild weather conditions with some precipitation. It is sufficient to have temperatures just below 0°C for a relatively short period of time in order for ice to form. However, during extreme cold weather conditions where the temperatures are under -15°C for a lengthy period of time, the fjord is often free from ice formation.

In order for ice to form, there must be a stable gradient in the uppermost centimetres of the water masses. This stable cross-section is a result of a strong gradient of salinity and is formed by a supply of fresh water in the form of precipitation. Such a layer will easily be decomposed by a mechanical turbulence (wind).  相似文献   

17.
改进的BTOPMC模型及其在水文模拟中的应用   总被引:2,自引:0,他引:2  
In this paper, a grid-based distributed hydrological model BTOPMC (Block-wise use of TOPMODEL) is introduced, which was developed from the original TOPMODEL. In order to broaden the model's application to arid regions, improvement methodology is also implemented. The canopy interception and soil infiltration processes were incorporated into the original BTOPMC to model event-based runoff simulation in large arid regions. One designed infiltration model with application of time compression approximation method is emphasized and validated for improving model's performance for event hydrological simulations with a case study of Lushi River basin.  相似文献   

18.
Abstract

Urban heat islands result from human modification of land surfaces. Snow cover reduces heating due to its reflectivity; however, urban snow is quickly plowed, thus altering surface radiative properties. The goal of this study was to evaluate the extent to which municipal snow removal affects the magnitude of solar input associated with changes in the radiation balance. Incoming and reflected shortwave radiation, surface radiating temperature, air temperature, and snow depth were measured with portable devices at eight sites in Syracuse, New York. Sites were classified as cleared, undisturbed, or snow piles. Measurements were taken following fresh snowfall, and continuing until snow had melted. A HOBO weather station provided hourly baseline conditions. Longevity of snow varied across snow site types, with greater persistence when in piles and on open areas. Albedo was reduced and surface temperatures were higher over cleared areas. The difference between absorbed energy due to clearing was quantified using an albedo regression model for undisturbed sites and comparing these to average reflectivity of cleared surfaces. The magnitude difference over the study period ranged from 841 million to 1670 million MJ. Snow plowing is therefore a significant source of additional energy that enhances the winter urban heat island.  相似文献   

19.
伊洛河流域森林景观变化驱动因素   总被引:2,自引:1,他引:1  
1 Introduction Landscapes are the outcome of the interaction between socio-economic and natural forces (Wrbka et al., 2004). During the evolution of cultural landscapes throughout the world, human activities have become dominant factors shaping most lands…  相似文献   

20.

This paper describes one geometrical method of simulating the spatial distribution of snow cover. Geographical Information Systems (GIS) and precise Digital Elevation Model (DEM) were used in the simulation. The model is based on empirical parameters called coefficients depending on slope aspect and inclination. As a result, this model predicts that windward convex terrains remain snow-free during winter. This snow cover distribution was validated by usage of an air photograph taken in early spring, and the distribution of vegetation patches which represent the outer fringes of snow covered areas. Low ground temperatures together with high DC resistivities, which suggest the presence of permafrost, were identified in simulated snow-free areas.  相似文献   

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