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1.
一、转移农民依然是三农问题的重中之重 三农问题是当前中国面临的最棘手问题之一,事情千头万绪,牵涉到农民增收、粮食安全、村民自治、环境治理、精神文明建设、社会保障等一系列问题,然而.在这众多的头绪中,转移农民依然是三农问题的重中之重,这是由中国的国情决定的.根据2005年的资料显示,中国农村人口约占全国总人口的60%,但农业产值只占到全国GDP总值的10%左右,并且根据国际规律,随着一国经济的不断发展,农业产值在整个国民产值中的比例将会呈现出不断下跌的趋势.可以想象,如果不继续大量地转移农民,让占全国人口60%的农民来分配不到国家GDP总值10%的农业产出,无论怎样分配,都必然会导致城乡差距的进一步扩大. 相似文献
3.
Urbanization has a massive impact on ecological function and impedes the provisioning of environmental services. The interaction between urbanization and the environment has been researched extensively. However, the existing research focused on the urbanization characteristics of large metropolitan areas. In this paper, we investigate the urban fragmentation patterns of small and mid-sized cities in Idaho, USA. To capture the urban morphology for each site within the study we use both concentric ring and transect analysis as well as several spatial/landscape metrics. Our results show that the characteristics of urbanization in small and mid-sized cities (and those in second-tier regions that attract relatively little scholarly attention) are consistent with growth phase theory of urbanization, urbanization along a gradient, and urbanization patterns of metropolises. 相似文献
4.
A review of demographic trends and health and social problems in the fast growing urban areas of the world indicates that, in the future, increasing numbers of people will be living in precarious socioeconomic conditions which impede the achievement of health. It is estimated that from 4.4 billion in 1980 the world's population will increase to 6.2 billion by the year 2000. The urban population will increase from 1.8 to 3.2 billion during the same period, over 2 billion of which will be in developing countries. The rapid and often uncontrollable demographic growth of cities, especially in the developing world, stimulates the demand for resources, intensifies their utilization and creates an intolerable pressure on the urban infrastructure and physical environment. A number of action oriented projects to combat disease and contamination have been successful. Projects in Addis Ababa, Ethiopia, Colombo, Sri Lanka, Hyderabad, India, Guayaquil, Ecuador, Lima, Peru, and Rio de Janeiro have been implemented under a partnership among WHO, UNICEF, the Netherlands Aid Agency, the World Bank, and other international organizationals and governments. These projects all emphasize the fundamental role of community organizations, especially that of women; low-cost technology and the need to mobilize and efficiently use locally available resources; an ecological multisectoral concept of health whereby action concerning the environment, education, income generation and the availability of food, all with a powerful disease preventive potential, carry equal if not greater weight than the efforts to provide the population with health centers or implement curative practices. All these projects are focused on marginal groups; many were initiated by imaginative individuals or groups with a considerable amount of social orientation and motivation, and often, at least in the beginning, without the support of governments, nongovernmental or international organizations. It is important to study these projects in their accomplishments and failures; to help describe them and disseminate related information when appropriate; and to promote political and technical support for those which are successful so that they can rapidly come out of the experimental/demonstration phase and be expanded to become part of routine programs. 相似文献
5.
This article analyzes glurbanization theory. The theory rests on the premise that major urban transformations and reconfigurations through interscalar strategies and rescaling processes are a good method of increasing the capacity and status of cities (and their regions) to develop global competitive advantages. This urban model stems from the fact that cities are increasingly exposed to global competition. An important tenet of glurbanization is that large cities worldwide, called ‘global cities’, come to share the same essential attributes (i.e., cityscapes, skyscrapers, financial markets, cultural centers, etc.). Another important tenet of glurbanization is that it collapses the global and the local: urban spaces are restructured so that globalization does not become just a top-down hierarchical design whereby the nation-state dictates how things work; rather, globalization is made to happen both from ‘below’ and from ‘above’. 相似文献
6.
Urbanization has resulted in obvious changes in plant species diversity. We analyzed the dynamics of ruderal species diversity in Harbin over the past half century using historical data collected in 1955 and data of the present spatial distribution in 2010–2011. The results show that, the number of ruderal species decreased from 611 to 175 with remarkable tendency of decreasing in perennial species and increasing in winter annual species in the past half century, which caused the shift of life form spectrum from perennial mono-dominant type to summer annual and perennial co-dominant type. Meanwhile, the proportion of tropical originated species increased and the proportion of temperate originated species decreased which were considered to relate with the increase of temperature in urban area during the past half century. Moreover, there was a distinct decrease of the proportion of aquatic and hygrophytic ruderal species while an increase of mesic and xeric ruderal species which suggested a drought trend in urban habitats that consistent with the change of land use characterized as decrease of natural water bodies and wetlands and increase of urban land. Comparison of ruderal species along urbanization gradient also got the similar results with the above results from analysis on temporal scales and confirmed the effect of urbanization on decreasing plant richness. Our results suggested that land use change combined with its effect on temperature and disturbance regimes in urban habitats preferred species with short life span, high drought tolerance, fast growth rates and high seed yields. 相似文献
7.
Urbanization generally reduces wildlife populations. Individual species responses, however, are often highly variable, and such variability can be explained by differences in species ecological traits. To examine this hypothesis, we focused on two co-occurring land snails, Ezohelix gainesi and Euhadra brandtii sapporo; the former is ground-dwelling and the latter is arboreal. We first estimated their population densities at nine sites distributed along an urbanization gradient: three were located in continuous natural forests, three at the edge of natural forests, and the rest in small isolated forests in urban areas. As a result, the ground-dwelling E. gainesi occurred at highest density in urban forests, followed by forest edges and continuous forests. By contrast, the arboreal E. b. sapporo occurred at highest density in continuous forests, but declined in forest edges and urban forests. We then conducted manipulative field experiments to quantify changes in predation pressure on these species. Ground-tethered E. gainesi and E. b. sapporo were repeatedly predated upon by forest-living mammals in continuous forests, but their survival rates increased in forest edges and urban forests. By contrast, canopy-tethered E. b. sapporo maintained high survival rates in all three forest types. The results indicate that a lack of mammalian predators enables ground-dwelling species to occur at high densities in urban forests, whereas the arboreal species was not affected by this predator relaxation effect. The combination of species-specific behavioural traits and changes in predator communities across an urbanization gradient has important effects on the biodiversity of urban ecosystems. 相似文献
8.
一、“宅基地换房”模式提出的背景天津市是全国三个特大城市之一.根据《2007年天津市国民经济与社会发展统计公报》的数据,2007年末全市常住人151115万.其中农村人15378.77万.占总人15的33.97%。从就业和产值的结构来看.2007年天津市在第一产业就业的人口比例为13.09%.而创造的产值仅占全市GDP的2.05%。 相似文献
9.
Urban Ecosystems - The original version of the article unfortunately contained mistakes in the legends of Fig. 3. The legends (1) Blue square: Euhadra brandtii sapporo, ground is changed... 相似文献
10.
China’s economic development over the past three decades has been remarkable due to the establishment of the “Reform and Opening-up” program. Meanwhile, urbanization, one of the most intensive human activities, has significantly changed the land cover across China. Here we used remote sensing data and landscape metrics to explore the spatiotemporal patterns of urbanization in two large Chinese cities, Chengdu (1978–2010) and Chongqing (1976–2010). Results suggested that urban land in both cities experienced a significant growth and became 9.8 and 6.3 times larger than the initial for Chengdu and Chongqing, respectively. The edge-expansion was the major urban growth form for both cities, accounting for more than 40 % of total three types (i.e., edge-expansion, infilling, and outlying) although fluctuating during the whole period. Both cities started a spurt growth in the 1990s although the starting times were different (1992 and 1996 for Chengdu and Chongqing, respectively) because of different policies. Spatial distribution of the newly developed urban lands was largely constrained by topography. Landscape analysis not only revealed an increasing fragmentation and complexity in the study area under the impact of urbanization, but also tested the hypothesis on urbanization patterns. 相似文献
11.
面对城市化快速发展的形势,天津的规划管理工作必须树立全面、协调和可持续的科学发展观,紧紧围绕"把天津建设成为现代化国际港口大都市"的城市定位,正确处理城市规划与区域规划的协调发展关系,构建运转协调、行为规范、职责分明、办事高效的规划管理体系,推动天津城市化快速发展目标的顺利实现. 相似文献
12.
Amin , Ash and Thrift , Nigel 2002 Cities: Reimagining the Urban Cambridge : Polity Press 192 pp. £ (hardback) £ (paperback) 相似文献
13.
Studies of flowering and leafing phenology have dramatically increased during the last few decades because changes in plant
phenology can be indicative of possible effects of climate change at multiple scales. This article reviews the available literature
focusing on the effects of urbanization on flowering phenology. The literature of flowering phenology in urban environments
suggests that spring-blooming plants in a variety of ecosystems in North America, Europe, and China tend to bloom earlier
in the city than in the surrounding un-urbanized habitat. Moreover, ephemerals, early spring bloomers, and insect-pollinated
plants in these environments tend to be more sensitive than perennials, mid- or late-spring bloomers, and wind-pollinated
plants. Researchers attribute advanced flowering in urban environments to the Heat Island Effect. The potential ecological
consequences of changes in flowering phenology in urbanized areas are not well understood or explicitly studied. However,
studies in global biology have suggested that climate change may result in a series of important ecological consequences as
well as human-related problems such as earlier and extended allergy seasons. More field-based studies are needed to elucidate
this issue. 相似文献
14.
This paper examines the ability of the existing strike literature, as typified by the strike models of Ashenfelter and Johnson
(1969) and Shalev (1980), to explain the pattern of strike activity in the United States in the period 1967 to 1977. After
demonstrating the limited ability of these models to explain the strike activity during this period, an alternative model
is proposed which is related to the “Pure Bargaining Theories” that stress the role of economic forces in terms of their effect
on uncertainty in the bargaining process. 相似文献
16.
由新的生产工具所推动的并由社会生产力所决定的经济全球化已不是一种选择,而是一种必然,它决定着这个时代发展的方向及其内涵.当今世界,汹涌澎湃的全球化浪潮已经一浪高过一浪地滚滚而来,世界上的任何地方都无法摆脱它所带来的影响和巨大诱惑. 相似文献
17.
While migration has been found to enhance welfare across a range of settings, most of the literature focuses on rural‐to‐urban migrant flows. Using a unique dataset from north‐western Tanzania, this article probes an important, yet overlooked, link between land markets and rural‐to‐rural migration. A mixed‐methods approach is used to discern how these two forces are intertwined in village life. Results indicate that household decisions to migrate are particularly influenced by the ease of market‐based land access in their new communities. This suggests that labour mobility may be facilitated through the development of a well‐functioning land market. 相似文献
18.
Many studies have described the effects of urbanization on species richness. These studies indicate that urbanization can
increase or decrease species richness, depending on several variables. Some of these variables include: taxonomic group, spatial
scale of analysis, and intensity of urbanization. Recent reviews of birds (the most-studied group) indicate that species richness
decreases with increasing urbanization in most cases but produces no change or even increases richness in some studies. Here
I expand beyond the bird studies by reviewing 105 studies on the effects of urbanization on the species richness of non-avian
species: mammals, reptiles, amphibians, invertebrates and plants. For all groups, species richness tends to be reduced in
areas with extreme urbanization (i.e., central urban core areas). However, the effects of moderate levels of urbanization
(i.e., suburban areas) vary significantly among groups. Most of the plant studies (about 65%) indicate increasing species
richness with moderate urbanization whereas only a minority of invertebrate studies (about 30%) and a very small minority
of non-avian vertebrate studies (about 12%) show increasing species richness. Possible explanations for these results are
discussed, including the importance of nonnative species importation, spatial heterogeneity, intermediate disturbance and
scale as major factors influencing species richness. 相似文献
19.
In this article we analyse the location patterns of firms that provide specialized advanced producer services (APS) to international commodity chains that move through seaports. Such activities can take place in world cities or in port cities. The analysis of APS location patterns in port cities provides a good opportunity to integrate the study of world cities into the framework of Global Production Networks. Based upon our empirical findings, we conclude that while port-related APS activities predominantly follow the world city hierarchy, a number of port cities stand out because they act as nodes in global commodity flows and as centres of advanced services related to shipping and port activities. Based on these empirical findings we address future avenues of research. 相似文献
20.
改革开放近30年来.我国的城镇化是伴随国家和地区产业结构不断升级、农村劳动力向城市地区不断转移、城市基础设施和社会服务设施日益完善、不断延伸而持续发展的。目前我国已进入了城镇化快速发展阶段.城镇数量和人口均达到了前所未有的规模.城镇作为经济社会的载体在国家和地方经济社会发展中的中心作用得到了进一步的发挥。已具雏形的城镇体系犹如现代化大厦的磐石和骨架.正引领国家现代化事业不断前进。 相似文献
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