共查询到14条相似文献，搜索用时 31 毫秒
1.
Meyzenq C 《Revue de géographie alpine / publieé par l'Institute de géographie alpine (Université de Grenoble)》1984,72(1):41-53
Recent demographic trends in the Alpine areas of France are examined. It is found that a shift of population away from the Cote d'Azur has occurred since 1975. The importance of tourism for population growth in the Alpine areas is noted. 相似文献
2.
Crop cover reconstruction and its effects on sediment retention in the Tibetan Plateau for 1900–2000
Geographically explicit historical land use and land cover datasets are increasingly required in studies of climatic and ecological effects of human activities. In this study, using historical population data as a proxy, the provincial cropland areas of Qinghai province and the Tibet Autonomous Region (TAR) for 1900, 1930, and 1950 were estimated. The cropland areas of Qinghai and the TAR for 1980 and 2000 were obtained from published statistical data with revisions. Using a land suitability for cultivation model, the provincial cropland areas for the 20th century were converted into crop cover datasets with a resolution of 1 × 1 km. Finally, changes of sediment retention due to crop cover change were assessed using the sediment delivery ratio module of the Integrated Valuation of Ecosystem Services and Trade-offs (In- VEST) model (version 3.3.1). There were two main results. (1) For 1950–1980 the fractional cropland area increased from 0.32% to 0.48% and land use clearly intensified in the Tibetan Plateau (TP), especially in the Yellow River–Huangshui River Valley (YHRV) and the midstream of the Yarlung Zangbo River and its two tributaries valley (YRTT). For other periods of the 20th century, stability was the main trend. (2) For 1950–1980, sediment export increased rapidly in the Minhe autonomous county of the YHRV, and in the Nianchu River and Lhasa River basins of the YRTT, which means that sediment retention clearly decreased in these regions over this period. The results of this assessment provide scientific support for conservation planning, development planning, or restoration activities. 相似文献
3.
The two concepts of “liudong renkou(floating population or FP)” and “renkou liudong(mobility of the floating population or MOFP)”, along with relevant data based on these two concepts, have long been used extensively in China’s research and policy making, playing a central role in Chinese studies of migration. Unlike the concepts of “migrant” and “migration” in the international literature, which are focused on people’s spatial mobility, “liudong renkou” and “renkou liudong” are identified and m... 相似文献
4.
Ko Ko Lwin Komei Sugiura Koji Zettsu 《International journal of geographical information science》2016,30(8):1579-1593
We can collect, store, and analyze a huge amount of information about human mobility and social interaction activities due to the emergence of information and communication technologies and location-enabled mobile devices under cyber physical system frameworks. The high spatial resolution of population data on a multi-temporal scale is required by transport planners, human geographers, social scientists, and emergency management teams. In this study, we build a space-time multiple regression model to estimate grid-based (500 m × 500 m) spatial resolution at multi-temporal scale (30-min intervals) population data based on the space-time relationship among geospatially enabled person trip (PT) survey data and incorporate both mobile call (MC) and geotagged Twitter (GT) data. Since using geospatially enabled PT survey data as dependent variables enables us to acquire actual population amounts, which strongly depend on MCs and social interaction activities. Although many grids have a strong correlation between PT and MC/GT, some show fewer correlation results, especially where the grids have factories, schools, and workshops in which fewer MCs are found but a large population is presented. Although GT data are sparser than MCs, people from amusement and tourist areas can be detected by GT data. The space-time multiple regression model can also estimate the different amounts of populations based on human travel behavior that changes over space and time. According to accuracy assessments, the night-time estimated results, especially between 00:00 and 06:30, strongly correlate with national census data except in places where the grids have railway and subway stations. 相似文献
5.
From 2020 to 2030, accelerating the “citizenization” of the migrant population is key to promoting urbanization and achieving common prosperity. The urbanization rate of the registered population in China is roughly 18% lower than that of permanent residents. The pressure of the ageing population and the lack of a labor force have caused big cities to introduce relevant policies to attract talent, and the citizenization process needs to be improved urgently, with a particular focus on megacities. The transformation in the number of registered residents in megacities varies greatly, and there is a lack of research on this topic, which makes it an important academic issue. Using both natural and social perspectives, we selected concise indicators and combined the possibility-satisfiability model to estimate the urbanization transformation gap of annual household registration. Further, we constructed a panel data model to empirically analyze the different factors leading to the gap of household registration in megacities. The main factors affecting the transformation of the registered population in megacities are medical services, as well as educational resources and the urban water supply. It is urgent for urban and rural administrators to change the current passive and rigid institutional mechanisms and to ensure flexible, normal governance. 相似文献
6.
7.
Graham E 《Applied geography (Sevenoaks, England)》1995,15(3):219-232
Singapore experienced an extraordinary demographic transition from a population growth of over 4% per year in the late 1950s to around 1.6% in the 1990s and below replacement fertility since 1986. In 1987 official government policy shifted to measures for increasing fertility. This paper explores whether Singapore's pronatalist policies can reverse the demographic transition. The present policies aim to selectively increase fertility among the well educated. By 1987 the slogan switched from "stop at two" to "have three, if you can afford it." The policy included tax relief for a third child and other measures to encourage a third child. The policies are expected to have a different influence on society according to one's education, income, and family size. The government target is to selectively increase population by 40% over 25 years. Singapore's transition may follow the theory that low fertility is attained in societies where kin relationships are less important than personal educational achievements. The three ethnic groups responded differently to educational and fertility policies. The Chinese acquired the best education and attained the lowest fertility. The Chinese, who comprised 76% of total population in 1986, continued to have low fertility, while increases occurred among the Malays and the Indians. Future trends are considered difficult to predict. A survey conducted in 1992 in Ang Mo Kio among 489 reproductive age respondents revealed that Malays had the earliest marriage and first births before the age of 25 years (75% of Malays and 50% of Indians). The Chinese had their first child at 25 years or older. Without controls for the age of the mother, a strong statistically significant association was found between ethnic group and age at marriage and age at first birth. The relationship was not supported for current fertility. A comparison of women married for 5 years or less and 5 years or more revealed that women in recent marriages showed a greater likelihood of postponing marriage and childbirth for all ethnic groups. Since 1987, third order births as a percentage of all births increased from 21.47% before 1987 to 23.11% during 1987-92, which only suggests the favorable impact of the pronatalist policy. Educational changes are likely to become more influential in affecting choice of family size. 相似文献
8.
Global and regional changes in working-age population exposure to heat extremes under climate change
Despite recent progress in assessing future population exposure, few studies have focused on the exposure of certain vulnerable groups, such as working people. Working in hot environments can increase the heat-related risk to human health and reduce worker productivity, resulting in broad social and economic implications. Based on the daily climatic simulations from the Coupled Model Intercomparison Project phase 6(CMIP6) and the age group-specific population projections, we investigate future c... 相似文献
9.
We inferred late Holocene Adélie penguin occupation history and population dynamics on Zolotov Island, Vestfold Hills, Antarctica, using geochemical data from a dated ornithogenic sediment core (ZOL4). Radiocarbon dates on fossil penguin bones in the core indicate that Adélie penguins occupied the island as early as 1,800 years before present (yr BP), following the retreat of the Sørsdal glacier. This occupation began ~1,200 years later than that observed at Ardley Island and King George Island, in the South Shetland Islands. Phosphorus was identified as the most indicative bio-element for penguin guano in core ZOL4, and was used to infer past penguin population dynamics. Around 1,800 years ago, the Adélie penguin populations at both Zolotov Island and Ardley Island increased rapidly and reached their highest levels ~1,000 yr BP. For the past ~900 years, the penguin populations at Zolotov Island have shown a general rising trend, with fluctuations, while those at Ardley Island have shown a moderate decreasing trend. The Adélie penguin populations at both Ardley Island and Zolotov Island showed a clear decline ~300 years ago, which we interpret as a response to the Little Ice Age, or a neoglacial cooling event. 相似文献
10.
The “Hu Line” has been regarded as one of the greatest geographical discoveries in China because it reveals the significant spatial relationship between human activity and natural environment. The spatial evolution of population on both sides of the “Hu Line” has had important implications for both urbanization and regional development and has attracted widespread attention during the dramatic economic and social changes since the implementation of reform and opening-up policy in China in 1978. Using Geographical Information System (GIS) techniques, this paper studied the stability of the “Hu Line” and the spatial patterns of population growth on each side by constructing a spatial database of China’s census data from 1982 to 2010. The findings are as follows: (1) In the last 30 years, the “Hu Line” has remained relatively stable, but a new tendency of population change has begun to emerge. The population ratio either side, namely, the southeast half (SEH) and the northwest half (NWH), of the “Hu Line” remains at roughly 94:6 (SHE: NWH). Noteworthy, the proportion of population in the SEH of the “Hu Line” has been decreasing slightly, while that in the NWH has been increasing slightly, as the latter has benefited from its higher rate of natural population growth. (2) The spatial patterns of population growth on both sides of the “Hu Line” were quite different. The degree of population concentration in the SEH increased faster than the NWH. Regions with a negative population growth rate have rapidly expanded; these were mainly located in the south of the “Qinling Mountains-Huaihe River belt” and northeastern China. Meanwhile, regions with a fast population growth rate were mainly concentrated in the Yangtze River Delta, the Pearl River Delta, and the Beijing-Tianjin metropolitan area. Thus, the spatial pattern of population growth in the SEH presented a concentration pattern that could be called “Matthew effect pattern”. (3) The spatial pattern of population growth in the NWH could be regarded as the “Relative Balance pattern.” In the NWH, the population growth rate was positive and the degree of population concentration was very low. There were many minority populations located in the NWH that usually lived in a dispersed pattern but had a higher rate of natural population growth due to the preferential population policy. There were also some regions with a negative rate of population growth in the NWH, which were mainly located close to the “Hu Line” and the Ancient Silk Road. (4) In the future, the spatial patterns of population growth on both sides of the “Hu Line” may continue to evolve. For the SEH, the capacity to attract more people to small and medium-sized cities and towns should be enhanced. For the NWH, the emphasis should be placed on promoting urbanization and enhancing population agglomeration in its major cities. 相似文献
11.
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
12.
13.
Serrano Martinez JM 《Acta geographica》1989,(79):20-37
This is an analysis of regional differences in population trends in Spain during the twentieth century. Data are from a variety of official sources, including the censuses of 1900, 1960, 1970, and 1981. The author notes that up until 1975, interregional migration flows had acccentuated regional economic differences. However, the economic problems that have occurred since 1975, coupled with the political changes associated with greater regional autonomy, have resulted in new trends in internal migration that could have significant effects on the future distribution of the country's population. 相似文献
14.
Journal of Geographical Sciences - Henan, China, is likely the most populous agricultural province worldwide. It is China’s major grain-producing area, with a continuously increasing... 相似文献