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1.
This article explores the special features of the rural–urban transformation in East Asia in the last 30 years within the broader context of the development strategies of Asian governments. Despite an ongoing commitment to the rhetoric of concern with rural development, food security and the alleviation of rural poverty, these policies have emphasised the important role of urbanisation as the prime process influencing economic growth. This is supported by the economic argument that the economies of scale, the creation of mass urban markets and the higher productivity that occur in urban places make them crucial to development. This paper argues that this approach creates a false dichotomy between rural and urban areas, whereas development should aim to increase the linkages between rural and urban areas aimed at producing societal transformations rather than separate rural and urban transitions. The paper then explores the empirical evidence of rural–urban transitions in East Asia with a more detailed case study of China, which is considered to be a crucial example because of the size of its population, the special conditions of market socialism and its institutional capacity to manage the rural–urban transformation. The final section focusses on the importance of developing spatial sensitivity to the management of the rural–urban transformation in the 21st century. Old divisions between rural and urban sectors must be replaced by planning that integrates urban and rural activities so that they adopt sustainable management strategies which utilise concepts of eco-systems in which rural and urban activities are linked, so as to create sustainable urban regions, cities and societies.
T. G. McGeeEmail:
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2.
Air (vapor and particle phase) samples were collected every 12 days at five sites near the North American Great Lakes from 1 January 2005 to 31 December 2013 as a part of the Integrated Atmospheric Deposition Network (IADN). The concentrations of 35 polybrominated diphenyl ethers (PBDEs) and eight other halogenated flame retardants were measured in each of the ~ 1,300 samples. The levels of almost all of these flame retardants, except for pentabromoethylbenzene (PBEB), hexabromobenzene (HBB), and Dechlorane Plus (DP), were significantly higher in Chicago, Cleveland, and Sturgeon Point. The concentrations of PBEB and HBB were relatively high at Eagle Harbor and Sturgeon Point, respectively, and the concentrations of DP were relatively high at Cleveland and Sturgeon Point, the two sites closest to this compound's production site. The data were analyzed using a multiple linear regression model to determine significant temporal trends in these atmospheric concentrations. The concentrations of PBDEs were decreasing at the urban sites, Chicago and Cleveland, but were generally unchanging at the remote sites, Sleeping Bear Dunes and Eagle Harbor. The concentrations of PBEB were decreasing at almost all sites except for Eagle Harbor, where the highest PBEB levels were observed. HBB concentrations were decreasing at all sites except for Sturgeon Point, where HBB levels were the highest. DP concentrations were increasing with doubling times of 3–9 years at all sites except those closest to its source (Cleveland and Sturgeon Point). The levels of 1,2-bis(2,4,6-tribromophenoxy)ethane (TBE) were unchanging at the urban sites, Chicago and Cleveland, but decreasing at the suburban and remote sites, Sturgeon Point and Eagle Harbor. The atmospheric concentrations of 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EHTBB) and bis(2-ethylhexyl)-tetrabromophthalate (BEHTBP) were increasing at almost every site with doubling times of 3–6 years.  相似文献   

3.
It is a fact that in U.S. the immigration between rural areas and city areas is free, but in China this type of immigration is restricted by HUKOU system (Hukou, namely the household registration system, was designed to control rural-urban in China). All of those national policies in city areas are much better than those in rural areas, so those corresponding differences bring about great discrepancy of the economic status (mainly including GDP per person and income per resident) between rural and city areas in the same urban region, especially in different urban re- gions because the percentage of urban residents in those urban regions is in-equable. The present paper mainly researches the topic of relationship between the percentage of urban residents and the economic status in an urban region in China, including the relationship between the economic and the political functions of a settlement in China during the process of urbanization.  相似文献   

4.
Relationships between abundance of basic net phytoplankton taxonomic groups (cyanobacteria, diatoms, and chlorophytes) and nutrient concentrations in water were studied on the Pas??ka River in years with varied water levels. In high water level conditions, large amounts of orthophosphates and total nitrogen from the catchment could favor development of cyanobacteria and chlorophytes. The species could be allochthonic. At low water levels, the factor stimulating phytoplankton development could be nutrients coming from mineralization of accumulated organic matter. The highest nutrient concentrations could favor diatom development. In such conditions, dominant taxa were autochthonic. In terms of numbers, F. capucina was dominant, and in terms of biomass—genus Spirogyra sp. It could come from plant periphyton inhabiting the concrete drops of the dam included in the river’s development in the vicinity of the hydroelectric power station.  相似文献   

5.
Quantitative and qualitative characteristics of cones and seeds and the emergence and survival of seedlings in the Siberian spruce (Picea obovata Ledeb.) were studied in different parts of the timberline ecotone on the Iremel’ Massif, the Southern Urals, from 2003 to 2006. In the productive year 2003, a decrease in the number of cones (from 110000 to 3000 per hectare), the yield of seeds (from 13 × 106 to 0.09 × 106 per hectare), and their laboratory germination rate (from 34 to 14%) with an increase in elevation above sea level was recorded. In 2004, significant differences in the number of seedlings per hectare were revealed between the lower, middle, and upper parts of the ecotone (85 200, 19 800, and 0–400 ind., respectively). It has been shown that the greater part of seedlings (76–96%) perish during the first cold period. New generations of spruce trees are formed only after productive years. Seed production and seedling mortality in spruce apparently depend not only on air temperature and soil moistening but also on snow depth and soil temperature, which change more abruptly along the altitudinal gradient.  相似文献   

6.
Environment, Development and Sustainability - Although sustainability assessment is widely discussed at Brazil, in Brazilian Amazon its use is still little applied, considering this territory is...  相似文献   

7.
Monthly anomalies of stormy wind–wave heights and return periods are evaluated using secular routine observations in the coastal zone of the northern Black Sea. It is shown that wind–wave anomalies in this region are characterized by high-amplitude quasi-periodical variability with typical timescale of about 50 years. This timescale is determined by temporal variability of the coupled ocean–atmosphere system and coincides with periodicity of Atlantic Multidecadal Oscillation. Atmospheric re-analysis data show that cyclonic activity over the Black Sea basin intensifies when North Atlantic is relatively cold and meridional forms of atmospheric circulation are more frequent in the North Atlantic-Eurasian region. This leads to generation of more frequent Black Sea storm events and enhanced recurrence of extreme waves and results in profound (and mostly negative) environmental consequences. When North Atlantic is relatively warm and meridional forms of atmospheric circulation are less frequent in the North Atlantic-Eurasian region, environmental conditions in the Black Sea region are calmer. Thus, statistics of dangerous events can be wrongly estimated even if relatively long-term (~30 years) time series are considered and interdecadal variability of wind–wave anomalies must be taken into account when the risk assessment is accomplished.  相似文献   

8.
Spatio-temporal variations in the technetium-99 content of Fucus serratus samples from the French coast of the English Channel were studied between 1982 and 1984 using various sampling strategies. The lack of constancy in measurements from within the seaweed zone of the same station is revealed by a variation of 18% in the mean contents of samples collected from different sampling levels, a variation which reaches 41% if the extreme values of all results are taken into account. Regional variations over the Channel as a whole show an asymmetric diminution of the 99Tc content of the seaweed on the two sides of the liquid effluent discharge outlet from the reprocessing plant at La Hague and this confirms a predominant drift of Channel waters towards the North Sea. Variations with time at three stations during 1983 and 1984 have revealed that there is a time-lag between fluctuations observed in the discharges and those in F. serratus. In addition, a periodic component observed at the Roscoff and Wimereux stations, where the 99Tc content of the seaweed varies by a factor of 2–3 between winter and summer periods, could be correlated with seasonal changes both in the metabolic state of F. serratus and in the currents to the south-west of Cap de La Hague. 99Tc, which here has no radiological impact on man, would thus appear to be a radioactive label for sea waters and one which is particularly sensitive to variations in environmental conditions.  相似文献   

9.
The radon activity concentration in ground water from drilled and dug wells on the horst S?der?sen in Southern Sweden has been determined with two different methods, gamma activity measurements with a germanium HPGe detector and alpha activity measurements with plastic track detectors. The results are consistent. High activity concentration is connected to granite bedrock. Dug wells have low concentrations and no trivial correlation between concentration and depth of the well is found. Large local variations exist. Activity concentrations > 700 Bq/l appear to be associated with leakage from layers of volcanic origin. The concentration from drilled wells is found to be quite constant over a 3 year period but short time variations appear to be significant. Evaporation from the open surface of a normal cooking vessel is slow with an activity gradient delta A/A of about 0.1-0.2 per hour at room temperature whereas even modest heating of water in e.g. a coffee machine is very efficient and reduces the radon activity concentration by > 90% in one process.  相似文献   

10.
The Ouémé River is one of the most important rivers in the Republic of Bénin. It is 510 km long and its catchment drains 75% of the country. In this study, organochlorine and organophosphorous pesticide residues were measured in more than 35 sediment samples collected on nine locations along the Ouémé River from upstream to downstream. Except for one location, Tanéka-Koko, all areas were contaminated by more than 20 pesticides. Organochlorine pesticides identified in sediment samples included pp'-DDE, op'-DDD, pp'-DDD, op'-DDT, pp'-DDT, alpha-endosulfan, beta-endosulfan, endosulfan sulphate, alpha-HCH, beta-HCH, lindane, aldrin, dieldrin, endrin, telodrin, isodrin, cis- and trans-heptachlorepoxide, hexachlorbutadiene, hexachlorobenzene and octachlorostyrene. The organophosphorous pesticide chlorpyrifos, used in a new formulation to protect cotton, was also identified. In some areas, the concentrations of organochlorine pesticides in the sediment of the Ouémé River exceeded environmental quality standards and are reason for concern.  相似文献   

11.
12.
By presenting stakeholders’ competing representations of an extraordinary geological formation, an island with a surface that is comprised of runoff from an infamous mud volcano in East Java, this article explores the communicative openings and closures that arise during an environmental disaster. A particular concern is attuning communicative practices to the diverse human and nonhuman actors that not only produce disasters but also shape our understandings and responses to disasters. Drawing on the work of Bruno Latour, this article suggests that non-anthropocentric modes of inquiry present new communicative and political possibilities for pursuing both social justice and safe environments. While this article focuses on a specific set of incidents in Indonesia, this project develops tools and perspectives that can be applied to environmental conflicts at other places.  相似文献   

13.
An attempt at population analysis of sables in the Ural–Ob region of the species range was made with the use of vast biological material (craniometry, 1909 specimens; ecological structure, 2157 specimens; and coat color, 439169 pelts). Population groups in the region were mainly described on the basis of morphological, geographic, historical, and ecological criteria. Seven spatially separated population groups were found, which were named after the main rivers of their habitats: the Tavda–Konda–Sos'va, Dem'yanka, Salym–Yugan, Agan–Vakh, Kazym–Nazym, Nadym–Kunovat, and Pur–Taz groups. They distinctly differed from one another with respect to cranial measurements, coat color, and some structural demographic parameters. In some cases, morphological differences reached the subspecies level. The data obtained make it possible to revise the pattern of geographic variation within the species range.  相似文献   

14.
During 1998 regional surveys were conducted to evaluate natural radiation exposure of people in the vicinity of the six Spanish nuclear power stations. Indoor radon, external gamma dose rates outdoors and indoors and radioactivity in soil were measured in these surveys. The highest mean annual effective dose to the population was found in the surroundings of the Almaraz nuclear power plant in the province of Cáceres and was mainly due to the presence of high radon concentrations in homes. In order to make a more accurate assessment of the dose coming from the radon in this area, a new and more extensive surgery on indoor radon with a total of 380 measurements was carried out in 2000 in the Campo Ara?uelo region around the Almaraz nuclear power station. From the results obtained in this survey, a population-weighted mean annual effective dose from radon exposure of 1.7 mSv y(-1), 44% lower than that previously reported in 1998, was estimated for the whole Campo Ara?uelo region. The maximum dose value due to radon exposure, about 4 mSv y(-1), was reached in the so-called La Vera area located in the north of this region. The relationship between the indoor radon concentrates experimentally measured, the geological characteristics of this geographic area and the information provided by the radiation map of the Spanish MARNA Project is also analyzed, confirming that La Vera area should be considered as a high radon level area.  相似文献   

15.
This paper attempts to determine whether and to what extent forest birds take the risk of feeding in an open area in winter. In each of three plots the extra food (lard) was initially placed on the border of the forest and open area and then moved into the open area and located within 15, 30 and 45 m from the edge of the forest. Only in one plot the total number of all the birds feeding on lard significantly decreased along with the food being moved away from the edge of the forest. In other plot the number of the most numerous Great Tit Parus major and Blue Tit Cyanistes caeruleus significantly increased along with the food source being moved away into open area. The numbers of the other 7 species of birds fell or did not have directional nature. Only in one plot the aggregation (the number of individuals of a given species feeding simultaneously) increased significantly along with moving the food into open area. In other plots differences in aggregation did not have the directional nature and, in most cases, were not significant.  相似文献   

16.
A global change assessment required detailed simulation of water availability in the Elbe River basin in Central Europe (148,268?km2). Using the spatially semi-distributed, eco-hydrological model SWIM, spatial calibration was applied. For 225 sub-areas covering the model domain (134,890?km2), evapotranspiration and groundwater dynamics were individually adjusted. The calibration aimed at good correspondences with long-term run-off contributions and the hydrographs for two extreme years. Measured run-off was revised from water management effects to produce quasi-natural discharges for calibration. At some gauges, there were large volume differences between these reference data and the simulations of the spatially uncalibrated model. Most affected were some sub-basins in the Czech part of the basin where the density of available climate stations was much lower than the German part. Thus, both erroneous precipitation data and systematic flaws in the evapotranspiration module of SWIM could have caused the differences. In order to identify the major error source and to validate the choice of spatial calibration parameters (evapotranspiration and groundwater dynamic corrections), MCMC analyses were made for three Czech areas. Optional precipitation correction had been considered by a third calibration parameter in the MCMC assessment. In two of the three cases, it can be shown that evapotranspiration corrections are preferable as precipitation errors are negligible. In the third case, where the analyses indicate a substantial error in precipitation data, an interpolation problem of the climate data at the edge of the model domain could be found. Hence, the applied method shows its potential to identify specific sources of uncertainty in hydrological modelling.  相似文献   

17.
In the Republic of Bénin, aquatic ecosystems are subject to poisoning risks due to the inappropriate use of pesticides, such as washing of empty bottles in rivers and using pesticides to catch fish. In some areas, cotton fields are located near riverbanks, increasing the probability of pesticide emission to the river. To assess contamination levels in the Ouémé River catchment area, different fish species were collected from different geographical areas along the river. DDT, its metabolites and isomers were the most frequently identified pesticides in fish flesh, alpha-endosulfan, beta-endosulfan, dieldrin, telodrin, lindane and octachlorostyrene were also detected. Concentrations of pesticide residues in fish ranged from 0 to 1364 ng/g lipid. A preliminary risk assessment indicated that the daily intake of chlorinated pesticides by people consuming fish from the Ouémé River still is rather low and does not present an immediate risk.  相似文献   

18.
1 INTRODUCTION Located in the transition area of the natural zones between north and south as well as the typical subtropical zone featured with warm-wet in the summer and cool-moisture in the winter (Shen, 1986; Chen et al., 2001), the MiddleYangtze reach is of great importance in the development and flood control of this region (Chen et al., 2001; Yin and Li, 2001). Due principally to the special geological setting and geographic location, the lower Jingjiang reach, typical of vast fl…  相似文献   

19.
20.
The southern Yucatán Peninsular Region project was designed from the outset as an integrative, multidisciplinary program of study examining tropical deforestation in the largest track of seasonal tropical forest remaining in Mexico and in which smallholder agriculture and a major biosphere reserve are juxtaposed in regard to land uses and covers. Treating land as a coupled human–environment system, the project joins the remote sensing, environmental, social, and modeling sciences in a way that is now recognized as land change science. This paper introduces the project, the study region, and six papers that explore some of the coupled system dynamics in the region. These include the sub-regional variation in deforestation, the pan-regional adoption or anticipation of cattle ranching, the emergence of divergent household agricultural and overall livelihood strategies, the roles of cultural and household histories in agricultural livelihood choices, the temporal intensification of swidden cultivation and its implications for forest species, and carbon stocks across cultivation units, including a new econometric modeling application to forecast changes in these stocks.  相似文献   

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