共查询到20条相似文献，搜索用时 108 毫秒
1.
2.
Thomas Bittner 《International journal of geographical information science》2013,27(5):825-850
For inherently vague and granular phenomena such as ecoregions, ecosystems, biomes, and biotopes, the interplay of granularity and vagueness leads to a trade-off in the classification and delineation of such phenomena: the goal of preciseness (lack of vagueness) of the delineation contradicts the goal of building a sophisticated classification system using the Aristotelian method of classification. This trade-off is based on the reliance on local qualities for a precise delineation of particular regions and the reliance on nonlocal qualities that serve as differentia in the Aristotelian classification. An ontological analysis of the logical interrelations between vagueness, granularity, and scale is critical for developing logically rigorous, nonlocal, and nonarbitrary classification and delineation systems for inherently vague and granular geographic phenomena. 相似文献
3.
4.
5.
This paper uses data for the period 1950–2050 compiled by the United Nations Population Division together with methods including spatial autocorrelation analysis, hierarchical cluster analysis and the standard deviational ellipse, to analyze the spatio-temporal evolution of population and urbanization in the 75 countries located along the routes of the Silk Road Economic Belt and the 21st-century Maritime Silk Road, to identify future population growth and urbanization hotspots. The results reveal the following: First, in 2015, the majority of Belt and Road countries in Europe, South Asia and Southeast Asia had high population densities, whereas most countries in Central Asia, North Africa and West Asia, as well as Russia and Mongolia, had low population densities; the majority of countries in South Asia, Southeast Asia, Central Asia, West Asia and North Africa had rapid population growth, whereas many countries in Europe had negative population growth; and five Belt and Road countries are in the initial stage of urbanization, 44 countries are in the acceleration stage of urbanization, and 26 are in the terminal stage of urbanization. Second, in the century from 1950 to 2050, the mean center of the study area’s population is consistently located in the border region between India and China. Prior to 2000, the trajectory of the mean center was from northwest to southeast, but from 2000 it is on a southward trajectory, as the population of the study area becomes more concentrated. Future population growth hotspots are predicted to be in South Asia, West Asia and Southeast Asia, and hotspot countries for the period 2015–2030 include India, China, Pakistan and Indonesia, though China will move into negative population growth after 2030. Third, the overall urban population of Belt and Road countries increased from 22% in 1950 to 49% in 2015, and it is expected to gradually catch up with the world average, reaching 64% in 2050. The different levels of urbanization in different countries display significant spatial dependency, and in the hundred-year period under consideration, this dependency increases before eventually weakening. Fourth, between 2015 and 2030, urban population hotspots will include Thailand, China, Laos and Albania, while Kuwait, Cyprus, Qatar and Estonia will be urban “coldspots.” Fifth, there were 293 cities with populations over 1 million located along the Belt and Road in 2015, but that number is expected to increase to 377 by 2030. Of those, 43 will be in China, with many of the others located in India, Indonesia and the eastern Mediterranean. 相似文献
6.
7.
Variations and trends of the freezing and thaw- ing index along the Qinghai-Xizang Railway for 1966?2004 总被引：1，自引：0，他引：1
Annual freezing and thawing index of 7 meteorological stations along the Qing-hai-Xizang Railway were calculated based on daily maximum and minimum temperature records for 1966?2004. Trends of annual freezing and thawing index were analyzed using the Mann-Kendall test and a simple linear regression method. The results show that: 1) The mean annual freezing indices range from 95 to 2300℃·d and the mean annual thawing indi-ces range from 630 to 3250℃·d. The mean annual freezing index of the 7 stations exhibited decreasing trends with decreasing rate of ?16.6– ?59.1℃·d /10a. The mean annual thawing index of these 7 stations showed increasing trends with the related decreasing rate is 19.83–45.6℃·d /10a. 2) The MK trend test indicated the significant decreasing trends (sig-nificant at < 0.05 significant level) in the annual freezing index for most stations except for Golmud. The significant increasing trends can be observed in the annual thawing index for 4 stations except Golmud and Tuotuohe. Golmud was the only station with no trends in both annual freezing and annual thawing index. 相似文献
8.
IntroductionFlood disasters have been serious since the ancient bines. AJthough we have Strengthened the harnessingofbig rivers since the founding of new Chin4 the threat still edeStS (see FigUre l). The Yellow myer hasbeen well known for its flood disasters since long time %o in China. There more than 1500 river burstShappened to the Yellow hiver in the paSt 2000 or 3000 years. Whereas floods of the Changjiang caverwere comparatively not serious in history, but its flood disasters have … 相似文献
9.
A fossilised paleoanthropological skull was discovered in November 1987, in the guily-head cliff on the east bank of Wenyu River near Xinza village, Yuling - town (hence the name Yuling-Man), Lingbao country, Henan Province, China. The skull, dated to an absolute U-isotope (U234 to U238 ) age of B. P. 156000 ± 13000 years, was found in the upper portion of the alluvial statum of the mid-Pleistocens Series, together with pateoliths of the Kehe Cutture System in the mid-late Paleolithic Periods. Although much research has been nomied out in this area, this is the first fossilised paleoanthropological skull in have been found. Therefore, this project, funded by the Natural Science Foundation/Henan Scientific Committee, is making new contributions to paleoanthropological research in China. 相似文献
10.
H. Jacob Carlson 《Urban geography》2018,39(5):726-745
Bangalore is held up as a model for how cities, particularly in the global south, should develop in the globalized information age, in which entrepreneurs with new access to international capital fuel service-sector-driven development. Expanding market forces cultivate cities of skilled middle-class workers whose increased consumption generates broad developmental benefits. Now known as the “Silicon Valley of India,” Bangalore was previously the capital of India’s public sector enterprises (PSEs), which laid important groundwork for the city of today, including the IT sector. I show how, by providing access to homeownership along with high wages and benefits tied to secure employment, Bangalore’s PSEs created the foundation for the city today and its middle-class character. The skilled workforce that PSEs created helped the IT sector emerge in the city. By examining this erased history, we see the role of the state in development projects, and consider alternative models for urban change. 相似文献
11.
In this article we argue that planning theory and practice should engage more with the normative political vision of Gilles Deleuze and Félix Guattari. They reject the transcendent authority of the State and arguably by extension, planning. As planners we should be concerned: need we reconceptualize, or abandon the planning project? We outline their vision, highlighting key concepts including lines of flight, revolution, the new land, and immanent organization, and use two cases from the United States and Mexico, the Food Commons and Center for Integral Farmer Development in the Mixteca, to show that planning in accordance with Deleuze and Guattari may indeed be possible. We end with questions: is what we describe planning? And what is planning – or what should it be? 相似文献
12.
Vegetation and sedimentation in the Lake Edward Basin, Uganda–Congo during the late Pleistocene and early Holocene 总被引：1，自引：1，他引：0
New palynological and sedimentological data obtained from the basal 3 m of core E96-2P from Lake Edward, Uganda–Congo record conditions wetter than present in the Edward basin from 11 000 to 6700 yr BP, in phase with other climate and vegetation records of northern hemispheric East Africa. Dominant pollen taxa include Celtis spp., Alchornea spp., Olea spp., and Moraceae indicating a moist semi-deciduous tropical forest. More xeric indicators such as Amaranthaceae and Asteraceae together with Poaceae comprise less than 5% of the pollen sum throughout this interval as compared with between 44 and 50% during a lake lowstand at 2000 cal yr BP and at the core top (near modern). The differences between these two assemblages suggest a 25 to 60% increase in annual precipitation during the early- to mid-Holocene as compared to modern (1500–2000 vs. 1200 mm/yr today). Early Holocene sediments in E96-2P are composed of laminated diatom oozes with moderately high total sulfur concentrations (2.8–4.7%) and no authigenic calcite, also indicative of conditions wetter than present. Between 9000 and 6700 yr BP, palynological and sedimentary proxies indicate sub-millennial-scale events related to changes in riverine discharge and runoff in the Edward basin. We attribute the variability in runoff, and hence precipitation, to Holocene variability in Indian or Atlantic Ocean SSTs or to shifts in the relative contribution of Indian and Atlantic moisture sources to the western Rift of equatorial Africa. 相似文献
13.
《地理学报(英文版)》2020,(1)
Aridity index reflects the exchanges of energy and water between the land surface and the atmosphere, and its variation can be used to forecast drought and flood patterns, which makes it of great significance for agricultural production. The ratio of potential evapotranspiration and precipitation is applied to analyse the spatial and temporal distributions of the aridity index in the Belt and Road region under the 1.5℃ and 2.0℃ global warming scenarios on the basis of outputs from four downscaled global climate models. The results show that:(1) Under the 1.5℃ warming scenario, the area-averaged aridity index will be similar to that in 1986–2005(around 1.58), but the changes vary spatially. The aridity index will increase by more than 5% in Central-Eastern Europe, north of West Asia, the monsoon region of East Asia and northwest of Southeast Asia, while it is projected to decrease obviously in the southeast of West Asia. Regarding the seasonal scale, spring and winter will be more arid in South Asia, and the monsoon region of East Asia will be slightly drier in summer compared with the reference period. While, West Asia will be wetter in all seasons, except winter.(2) Relative to 1986–2005, both areal averaged annual potential evapotranspiration and precipitation are projected to increase, and the spatial variation of aridity index will become more obvious as well at the 2.0℃ warming level. Although the aridity index over the entire region will be maintained at approximately 1.57 as that in 1.5℃, the index in Central-Eastern Europe, north of West Asia and Central Asia will grow rapidly at a rate of more than 20%, while that in West Siberia, northwest of China, the southern part of South Asia and West Asia will show a declining trend. At the seasonal scale, the increase of the aridity index in Central-Eastern Europe, Central Asia, West Asia, South Asia and the northern part of Siberia in winter will be obvious, and the monsoon region in East Asia will be drier in both summer and autumn.(3) Under the scenario of an additional 0.5℃ increase in global temperature from 1.5℃ to 2.0℃, the aridity index will increase significantly in Central Asia and north of West Asia but decrease in Southeast Asia and Central Siberia. Seasonally, the aridity index in the Belt and Road region will slightly increase in all other seasons except spring. Central Asia will become drier annually at a rate of more than 20%. The aridity index in South Asia will increase in spring and winter, and that in East Asia will increase in autumn and winter.(4) To changes of the aridity index, the attribution of precipitation and potential evapotranspiration will vary regionally. Precipitation will be the major influencing factor over southern West Asia, southern South Asia, Central-Eastern Siberia, the non-monsoon region of East Asia and the border between West Asia and Central Asia, while potential evapotranspiration will exert greater effects over Central-Eastern Europe, West Siberia, Central Asia and the monsoon region of East Asia. 相似文献
14.
Mark H. Cooper 《社会与自然资源》2017,30(7):812-828
ABSTRACTThis article examines the stomachs of ruminant livestock as a site of biotechnological intervention and analyzes efforts to reengineer ruminant digestion as a case of the real subsumption of nature. The livestock industry’s capacity to increase production is constrained by available grazing land and concern about environmental consequences of ever-increasing livestock numbers. Ruminants are also a significant source of greenhouse gases and the mitigation of methane is a recognized priority within the global climate framework. The pursuit of “sustainable intensification” and new technological fixes have been identified as preferred responses to these constraints. The case of ruminant methane calls into question assumptions about the primacy of accumulation, rather than regulation, in driving the real subsumption of nature. The pursuit of technological fixes within biologically based industries may be motivated by a need to stabilize the conditions of production, and regulation itself can provide an impetus for the real subsumption of nature. 相似文献
15.
Sami Moisio 《Urban geography》2018,39(9):1421-1424
This article suggests that the developments during the past few decades indicate a qualitative shift in the city/state relation, and conceptualizes this shift as the geopolitical growth of cities and city-regions. Originally a state-orchestrated process, today this is manifested in the attempts of major cities and city-regions, in particular, to demand a stronger national and international political role even as claims are made for urban separatism. This process is connected to a geopolitical reasoning of the heightened role of cities in inter-state competition during the age of post-Fordist capitalism. Furthermore, the geopolitical growth of cities and city-regions is partly constituted in academic theories and expert knowledges that combine certain type of urbanism, economic growth, and political success, and which in so doing destabilize state-centered geopolitical imaginations. 相似文献
16.
High-quality cultivation of specialized and sophisticated enterprises that produce new and unique products is an important starting point for consolidating the security foundation of China's industrial chain and supply chain. Using buffer zone analysis and the multi-scale geographically weighted regression (MGWR) model, this study explored the spatial distribution of specialized and sophisticated enterprises that produce new and unique products in the Yangtze River Delta region and influencing factors in 2021. The study found that: 1) Spatially, Shanghai is the main area where specialized and sophisticated enterprises that produce new and unique products are concentrated, followed by provincial capitals and cities on the coast and along rivers; The overall composition of the industry is unbalanced, and the real economic industries such as machinery and equipment manufacturing and high-tech manufacturing account for a relatively high proportion, but there are differences in different regions. 2) In terms of spatial agglomeration, differences between circles and the scale effect are obvious. Within each province, the spatial distribution of specialized and sophisticated enterprises that produce new and unique products in different cities is uneven. Region-wide, the overall spatial distribution pattern of "one pole and multiple cores" is evident. Shanghai is the main agglomeration area for these enterprises, and the provincial capital cities and cities that are the regional economic centers are the secondary agglomeration areas of these enterprises. 3) The four dimensions of influencing factors—physical geography, government, market, and society—have a scale effect on the spatial distribution of specialized and sophisticated enterprises that produce new and unique products. The degree of land development acts at a small scale, which is a local variable, and shows a large difference in the impact on the spatial distribution of these enterprises across the region. Factors such as elevation, government-business relationship, degree of marketization, number and scale of enterprises, degree of openness, logistics development level, and innovation environment are global variables, and except that the degree of marketization and the number of enterprises have a significant negative impact on the spatial distribution of these enterprises, the impact of all other factors is significantly positive. The research results can provide support for the optimization of the layout of new special expertise enterprise space in the Yangtze River Delta region, in order to provide reference for the formulation of new special expertise policies and industrial planning. © 2023, Editorial office of PROGRESS IN GEOGRAPHY. All rights reserved. 相似文献
17.
A comparative study on the ionospheric current systems in the Antarctic and Arctic regions 总被引：1，自引：0，他引：1 
下载免费PDF全文
下载免费PDF全文 ＡｃｏｍｐａｒａｔｉｖｅｓｔｕｄｙｏｎｔｈｅｉｏｎｏｓｐｈｅｒｉｃｃｕｒｒｅｎｔｓｙｓｔｅｍｓｉｎｔｈｅＡｎｔａｒｃｔｉｃａｎｄＡｒｃｔｉｃｒｅｇｉｏｎｓＸｕＷｅｎｙａｏ（徐文耀）（ＩｎｓｔｉｔｕｔｅｏｆＧｅｏｐｈｙｓｉｃｓ，ＡｃａｄｅｍｉａＳｉｎｉ... 相似文献
18.
Historical drought and water disasters in the Weihe Plain 总被引：2，自引：0，他引：2
YINShuyan HUANGChunchang LIXinyan 《地理学报(英文版)》2005,15(1):97-105
Through detailed statistics and analysis of drought and water disasters in the Weihe Plain in the historical period, we discovered that in more than 2300 years (from 370 BC to 2000 AD), natural disasters occurred most frequently in two periods. One is from 610 to 850 AD (from the late Sui Dynasty to the late Tang Dynasty) and the other is from 1580 to 2000 AD (after the late Ming Dynasty). Different natural disasters occurred synchronously, that is to say, when the drought occurred frequently, water disasters occurred frequently in the same periods. Frequencies of natural disasters, on the one hand, connected with climate changes and development course of ancient cities, while on the other, related closely to population changes. The excessive exploitation of natural resources and human disturbance and damages to ecological environment are the major reasons for the increased drought and water disasters. 相似文献
19.
Summary On 29 October 1998, the RGS-IBG invited delegates to a conference entitled 'Social exclusion and the city', with Geoff Mulgan (founder of the think-tank Demos and a policy advisor to Prime Minister Blair) as the keynote speaker. The event was well attended, providing much useful insight into the government policies of the 'Social Exclusion Unit' and ongoing academic research into the processes and problems of 'social exclusion'. Here we provide some general observations on the conference and some suggestions regarding the possible directions of the debate on social exclusion and inclusion. 相似文献
20.
The semiconductor industry typifies the international division of labor and exhibits significant structural differences in global trade in key product segments. The evolution of cross-border trade flows and dependency relationships, as well as trade organization patterns of manufactured products, equipment and materials for manufacturing, are investigated by constructing a global semiconductor trade relationship matrix and using the Gini coefficient and trade dependency index. It was found that:... 相似文献