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1.
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   

2.
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   

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The mass elevation effect(MEE) is a thermal effect, in which heating produced by long wave radiation on a mountain surface generates atmospheric uplift, which has a profound impact on the hydrothermal conditions and natural geographical processes in mountainous areas. Based on multi-source remote sensing data and field observations, a spatial downscaling inversion of temperature in the Tianshan Mountains in China was conducted, and the MEE was estimated and a spatio-temporal analysis was conduct...  相似文献   

5.
This paper presents findings from a study about the relationships between social change and settlement change in Samoa, where a form of landlessness is emerging in low income areas of the main town, Apia. It examines changing reciprocal kinship arrangements with respect to customary rural village plantation land and changes in both individual and household relationships with the church. Although these relationships are typically closely bound in Pacific island societies, recent field‐based research has revealed the expansion of landless urban settlements with households that are alienated from rural village‐based kin and, by extension, customary land.  相似文献   

6.
Historical drought and water disasters in the Weihe Plain   总被引:2,自引:0,他引:2  
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   

7.
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   

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AcomparativestudyontheionosphericcurrentsystemsintheAntarcticandArcticregionsXuWenyao(徐文耀)(InstituteofGeophysics,AcademiaSini...  相似文献   

10.
The article examines the role and contribution of preferential treatment of state enterprises to growth in the textile and garment industry. State enterprises are still the largest single sector in the textile and garment industry in Vietnam, but are losing market shares to private Vietnamese enterprises and foreign‐owned enterprises despite the benefits that they enjoy. However, in the present context of economic transition and keen competition in the global market, well‐managed state enterprises are attractive to foreign buyers of their products and have a role to play in market access abroad. This contrasts with the neoliberal notion that privatization is essential to competitiveness in the global market.  相似文献   

11.
Abstract

Based on daily mean temperature at 1863 meteorological stations in China, the trend in the thermal growing season was investigated and time-evolving probability distributions of temperature were examined. Results showed that during 1961–2015, the growing season was extended at rates of 1.5–5.0 days decade?1 in Northeast China, North China, Northwest China, and western and central parts of Southwest China. This change was ascribed to an earlier start of the growing season at rates of 1.5–3.0 days decade?1 in North China, the northern and western parts of Northeast China, and the northeastern part of Northwest China, and a later end at rates of 0.5–2.5 days decade?1 in Northwest China, the western and northern parts of Southwest China, and the northwest of North China. The earlier start of the growing season was in accordance with the rapid warming of lower portions of the spring temperature distribution in Northeast China, North China, and Northwest China. The later end of the growing season corresponded to rapid warming in the lower percentiles of autumn temperature distribution in Northwest China. The growing season is more sensitive to warming of lower percentiles of temperature distribution than other portions.  相似文献   

12.
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.
EffectoftheenvironmentinAntarcticaonimmunefunctionandelectroencephalogramYuYongzhong(于永中);WangZonghui(王宗惠);ZhangWencheng(张文诚)...  相似文献   

14.
During the first Chinese Scientific Expedition to the Arctic in July - September 1999, cyanobacteria in the Bering Sea were measured by epifluorescence microscopy. Cyanobacterial abundance varied from 0 to 7. 93 × 103 cell/ml and decreased along a northerly directed latitudinal gradient in horizontal distribution. Cyanobacteria did not occur at station Bl - 12 (north of 60 °N). Vertically, high cya-nobacterial abundance appeared in the upper 25 - 50 m and decreased rapidly below 50 m. There were no cyanobacteria at the 150 m. Seawater temperature and NH4+ -N are suggested to affect the distribution of cyanobacteria.  相似文献   

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To understand the changing rainfall–runoff relationship, this study examined climate and streamflow data in the Milwaukee River Basin in southeastern Wisconsin, of which four catchments with different degrees of urbanization were selected for analysis. This study analyzed temperature, precipitation, and streamflow data with a range of statistical methods, including the Mann–Kendall test, double-mass technique, and quantile regression. Runoff ratios and extreme flow indexes were higher in more urbanized catchments. Catchments with long-term data (>forty years) showed significantly increasing runoff ratios and slopes in double-mass curves. Overall, there are signs of changes in the rainfall–runoff relationship, but how much they can be attributed to land use changes is uncertain.  相似文献   

17.
《Urban geography》2013,34(7):988-1003
This article argues that urban skateboarding and the laws by which the city is governed must be understood as intertwined. The transformation of skateboarding's most popular practices from the 1970s onward are a product of an ongoing dialectical engagement between young people and the law. When faced with shifting landscapes of property and liability, young skaters have adapted their practices, seeking out new types of terrain. This search has led skateboarding into the public spaces of the city and regimes of urban governance. Contemporary efforts to build public skateparks in cities such as Seattle, Washington are properly contextualized as part of a continuing evolution of skaters' agency in responding to and capitalizing on openings in the legal landscape. By working both within the political system and constructing skateparks outside conventional political avenues, skatepark advocates seek spaces that are free from increasingly restrictive conventional logics of private and public property.  相似文献   

18.
This article examines the potential geographic inequities between major hazard events and U.S. presidential disaster declarations at the county level from 1965 through 2004. The previous literature suggests that the disaster declaration process is highly politicized and not necessarily based on need. We hypothesize that there is a spatial inequity between the receipt of disaster declarations and the distribution of major hazard events. The results indicate that the geographic distribution of disaster declarations is not totally explained by the spatial pattern of major hazard events. In some locales, state experience in submitting disaster requests and achieving success translates into more disaster declarations (holding everything else constant), providing further evidence of the political nature of the process.  相似文献   

19.
With the advent of climate change,winter temperatures have been steadily in-creasing in the middle-to-high latitudes of the world.However,we have not found a corre-sponding decrease in the number of extremely cold winters.This paper,based on Climatic Research Unit (CRU) re-analysis data,and methods of trend analysis,mutation analysis,correlation analysis,reports on the effects of Arctic warming on winter temperatures in Hei-longjiang Province,Northeast China.The results show that:(1) during the period 1961-2018,winter temperatures in the Arctic increased considerably,that is,3.5 times those of the Equator,which has led to an increasing temperature gradient between the Arctic and the Equator.An abrupt change in winter temperatures in the Arctic was observed in 2000.(2) Due to the global warming,an extremely significant warming occurred in Heilongjiang in winter,in particular,after the Arctic mutation in 2000,although there were two warm winters,more cold winters were observed and the interannual variability of winter temperature also increased.(3)Affected by the warming trend in the Arctic,the Siberian High has intensified,and both the Arctic Vortex and the Eurasian Zonal Circulation Index has weakened.This explains the de-crease in winter temperatures in Heilongjiang,and why cold winters still dominate.Moreover,the increase in temperature difference between the Arctic and the Equator is another reason for the decrease in winter temperatures in Heilongjiang.  相似文献   

20.
Using the observed data from 184 stations over the Yunnan-Guizhou Plateau (YGP) from 1961 to 2005, the long-term trends in sunshine duration, cloud amount, dry visibility (Vd), dry extinction, and water vapor over the YGP are analyzed. The results show that 85% of the stations recorded shortening annual sunshine duration, with the decrease rates between ?12.2 and ?173.7 h/10yr. Results of Mann-Kendall tests indicate that, among the stations with decreasing sunshine duration, 63.7% of them experienced an abrupt change that started in the 1970s and peaked in the 1980s. This decreasing trend has reversed in the early years of the 21st century. The cloud cover and water vapor content in the mid and lower levels over the YGP had no obvious changes during the study period. The annual averages of Vd declined from 34 km in the 1960s to 27 km at present. The annual mean dry extinction coefficient trended upward, from 0.176 to 0.190, on the YGP from 1980 to 2005. Analyses of cloud cover, water vapor, atmospheric visibility, and dry extinction coefficient revealed that emitted tropospheric aerosols (including air pollutants) resulting from increased energy consumption over the YGP could be a major factor influencing the reductions of sunshine duration and atmospheric visibility.  相似文献   

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