The current status of the study of population geography is examined, with some reference to the situation in the United Kingdom. The authors note that whereas the volume of studies in this area indicate its healthy growth, the subdiscipline has become increasingly distant from mainstream geography and runs the risk of being absorbed into general demography. The authors suggest that "population geographers, while taking a serious interest in the methods and philosophy of the neighbouring discipline of demography, should look elsewhere to find direction for their subdiscipline."excerpt

<p>Population agglomeration and dispersion are the most direct and the most concentrated expression of population spatial distribution pattern. The research on population agglomeration and dispersion spatial pattern and its formation mechanisms in a specific region will not only help to reveal the population agglomeration and dispersion in the region of the inherent law itself, but also benefit the study of the overall regional population spatial pattern, and even further, the study of regional economy agglomeration and urbanization. With the largest population and significant difference in regional natural condition and economy, China&rsquo;s population agglomeration and dispersion, in terms of not only the size but also complexity, are not comparable in the world. Thereby, research on the spatial pattern of China&rsquo;s population agglomeration and dispersion, which will contribute to grasping the essence of China&rsquo;s population spatial distribution pattern, is of great significance in both academy and practice. The article chose the classification evaluation of population agglomeration, which classified China into many population agglomeration types of different levels according to their population centralization index, and then, discussed them in each type. Based on this and the comprehensive consideration on the spatial distribution pattern of China&rsquo;s population, natural conditions, human environment suitability and economic development, the article generalized the spatial pattern of China&rsquo;s population agglomeration and dispersion.</p>

Hu Line uncovers one of China's most important characteristics of population paper distribution: East is dense, while west is sparse. Different from most previous research, this paper examined the differentiation and changes of population distribution on both sides of Hu Line from a perspective of spatial stratified heterogeneity instead. Geodetector was employed based on the spatial database of China's census data of 1953, 1982, 1990, 2000 and 2010 to reconfirm spatial position of Hu Line and analyzed changes of spatial stratified heterogeneity of population between southeast and northwest sides of Hu Line in different periods. Changes of population distribution since the founding of New China were found and the reasons for these changes were discussed. Major findings include: (1) From the spatial stratified heterogeneity perspective, Hu Line could be improved and optimized, at least, in some periods. Although the ratio of total population on both sides of Hu Line has roughly been kept at 94:6 since 1953, spatial stratified heterogeneity of population between the two sides (the southeastern side: the northwestern side) increased when Hu Line moves to south slightly in 1953, 2000 and 2010, which means population distribution was more homogeneous within either southeastern or northwestern region and heterogeneity was more remarkable between the two regions. (2) Heterogeneity decreased gradually since the reform and opening up. We found characteristics of population distribution converged on the two sides, especially since the 1990s when convergence between the two sides became apparent. This finding is significantly different from the conclusion of "remain unchanged" from most literatures. The reasons why heterogeneity reduced were: pattern of population distribution on the southeastern side changed from relatively even distribution among cities before 1990 to agglomeration in a few huge cities after 2000, while the degree of spatial agglomeration of population decreased slightly after the reform on the northwestern side. These changes have been confirmed by the analysis from cumulative distribution function and Gini coefficient. (3) On the whole, the effect of economic factors on population distribution has become more and more important, while the effect of natural environment and institution reduced. Combined effect from economic development, natural environment and institution resulted in two opposite directions of changes of population spatial distribution on the two sides. It should be emphasized that although general effect of natural environment has decreased, some natural factors, such as Three Gradient Terrains, still have significantly influence on population distribution in China.

China is the most populous country of the world.Besides her great numberof population she has also the most densely inhabited regions which are notcomparable with any other country of the world.

Spatial pattern of population distribution has a typical character of scale dependency. Fine-scale estimation of the population distribution has been a huge challenge in the field of population geography. In China, township is the finest administrative unit in official population census data. Thus, population density data at township level can be used to describe and characterize the population spatial pattern and changes elaborately, and support optimized layout plan of Chinese population, and government policy decision making. Township boundaries across 25 provinces in China had been collected in this study. The 5th national population census data was spatially joined to the boundary layer for population density calculation. Methods of Lorenz curve, geo-spatial analysis, and latitude/longitude transect had been applied to reveal the agglomeration degree, spatial patterns of population distribution with latitude and longitude. Based on the correlation and stepwise regression analysis, four variables, including relief degree of land surface (RDLS), water system density (WSD), road system density (RSD) and nighttime light index (NTL), were introduced to check the variety of population distribution in each province. The results showed that: (1) the variety of population distribution can be distinguished clearly by the mean population density on township scale than that of county level. (2) The overall population distribution can be characterized as dense in the southeast and sparse in the northwest, while lower population density occurs in some part of southeastern China, and vice versa. (3) The population density at township level along six designed longitude and latitude transects varies greatly. The possible impact factors include the three-level landscape features, local topography, regional economy, and the proximity to coastline, transportation hub, and hydrological systems. The correlation coefficient at provincial level, between the RDLS, WSD, RSD, NTL, and the population density has been identified as 0.56, 0.28, 0.61, and 0.69, respectively. At township level, topography and economy exert more impacts on population distribution in Liaoning, Jilin, Beijing, Tianjin, Shanghai, Hebei, Henan, Shaanxi, Shanxi, Shandong, Anhui, Jiangsu, Hunan, Hubei, Jiangxi, Zhejiang, Fujian, Guangdong, and Hainan. In addition to the four factors mentioned above, it is necessary to introduce more natural or social factors to explore the population distribution pattern in Tibet, Qinghai, Inner Mongolia, Yunnan, and Guizhou. This study expanded the research scale and dimension of the research in population geography research in China. The resulted population density dataset in 2000 is expected to enrich the baseline data resources for population geography development in China and the world.

Spatial distribution pattern of population and its evolution with the change of time and space is a hotspot and core content for human geography. Under the influence of complex environmental factors like geology, geography, ecology, and resources, population and social economy in western and eastern regions of China exhibit a lopsided development pattern over a long period of time. With the proposed New Urbanization Construction and the Belt and Road strategy, the social economy in western China, or even the whole China, has opportunities and space for development. Under the circumstance, this study on population distribution in different periods and areas in China will provide basis and spatial cognition for the development of relevant sustainable development policies and measures. Population data is acquired from the national statistical yearbook and population census data in different periods, and further built up spatial joint with the county administrative boundary in different periods. The population density is calculated based on the population data and regional area, and revised according to the adjacent years. With the support of geographical information technology, the inverse distance weighted method is used for spatial interpolation of the population density. Because of spatial density and distribution for the sampling points, average population density replaced interpolated results in western China. The study depicts the east-west dividing line of population density and discrepancies of population density in different periods and areas during 1935-2010 using county-level Chinese census data from six stages (1935, 1964, 1982, 1990, 2000, and 2010) with the index of population distribution structure, the Gini coefficient of population density, the movement trace of population center of gravity, and spatial autocorrelation analysis. The results showcase the dividing line of population density and discrepancies of population density in different periods and areas during 1935-2010. Because of the influence of history, environment and economy, the characteristics of population distribution evolution in different periods and areas keep changing in this study. It is known to all that the people are mainly distributed in Southeast China with little area, and population is much sparse in Northwest China, but with the larger area. Even though the population distribution trend of balanced development keeps increasing, the spatial distribution pattern of population has not changed obviously in the whole nation. The Hu Huanyong Line can still be a good summary of the characteristics of population distribution in China. To the west of the Hu Huanyong Line, population density in several provinces keep increasing during 1935-2010, such as Gansu Province and Ningxia and Inner Mongolia autonomous regions. The number of areas with population density with more than 50 people per kilometer increases greatly in the three provincial units. Moreover, the trend transferred to northwest China during 1935-2010. At the same time, the population distribution has obvious spatial autocorrelations in China in the last 80 years. In spatial scale, the hot and cold spots for population distribution have obvious aggregation, with great spatial difference in the whole China. The High-High regions are mainly distributed in South and East China where population density is very high and economy is developing repidly. The Low-Low regions are distributed on both sides of Hu Huanyong Line, namely, Southwest China and Northwest China. The natural environment and living standard are very poor in these regions. The spatial difference of population distribution in the High-Low and Low-High regions is very obvious because of local natural geographical environment and economic development, and these regions are usually distributed around the High-High and Low-Low regions. Thus, it is possible to coordinate the development between eastern and western China. We should understand the connotation and denotation of the question put forward by Premier Li Keqiang based on the natural law and economic development strategy of China in the new period. Meanwhile, people-oriented awareness should be further set up, and the New Urbanization Construction can be used to raise urbanization levels in China, thus improving the standard of living and environment.

China has witnessed unprecedented urbanization over the past decades. The rapid expansion of urban population has been dominated by the floating population from rural areas, of which the spatiotemporal patterns, driving forces, and multidimensional effects have been scrutinized and evaluated by voluminous empirical studies. However, the urban and economic development mode has been reshaped by the globalization and marketization processes and the socioeconomic space has been restructured as a consequence. How has the spatial pattern of floating population evolved against these backdrops? How has the evolution been driven by the interaction of state and market forces? What have been the contribution of population mobility to the urbanization of origin and destination regions and the evolution of China's urban system? The latest national censuses conducted in 2000 and 2010 offer the opportunity to systematically answer these questions. Analysis based on the county-level data comes to conclusions as follows. (1) The spatial pattern of floating population remained stable over the first decade of the 21st century. Three coastal mega-city regions, namely the Yangtze River Delta, the Pearl River Delta, and the Beijing-Tianjin-Hebei Region, were major concentration areas. As the emergence and rapid development of other coastal mega-city regions, the coastal concentration area of floating population tended to geographically united as a whole, whereas the spatial distribution within each region variegated significantly. (2) Floating population gradually moved into provincial capitals and other big cities in interior regions and its distribution center of gravity moved northward around 110 km during the study period. (3) Compared with extensively investigated inter-provincial migrants, intra-provincial migrants had higher intention and ability to permanently live in cities they worked in and thus might become the main force of China's urbanization in the coming decades. (4) The spatial pattern of floating population was shaped jointly by the state and market forces in transitional China. While the impacts of state forces have been surpassed by market forces in the country as a whole, they are still important in shaping the development space of central and western China. (5) The massive mobility of population contributed a large proportion to the increase of urbanization levels of both origin and destination regions and reshaped China's urban system in terms of its hierarchical organization and spatial structure.

With the rapid increase of the number and influence of floating population in China, it is urgent to understand the regional types of China's floating population and their spatial characteristics. After reviewing the current methods for identifying regional types of floating population, this paper puts forward a new composite-index method and its further modification method consisting of two indexes simultaneously: the net migration rate and gross migration rate. Further, those methods are empirically tested by using China's 2000 Census data at county level. The results show: (1) The composite-indexes method is much better than the traditional single-index method because it can measure the migration direction and scale of floating simultaneously and in particular it can identify the unique regional types of floating population with large-scale immigration and emigration. (2) The modified composite-indexes method, by using the share of a region's certain type of floating population to the total in China as weight, can effectively correct the over- or under-estimated error due to the rather large or small total population of a region. (3) The spatial patterns of different regional types of China's floating population are closely related to regional differentiation of their natural environment, population density and socio-economic development level. The three active regional types of floating population are mainly located in the eastern China with lower elevation, more than 800 mm precipitation, rather than in the region with higher population density and economic development level.

Using data from the 2000 and 2010 Chinese Population Censuses and applying a consistent definition of migration, this paper examines changing patterns of China's floating population during 2000-2010. We find that during the first decade of the 21 century, there have been significant changes in China's floating population, as reflected in continuing rise of interprovincial floating population and the rise of the floating population in China's western and interior regions, geographic diversification of destinations for the floating population, a major increase in interprovincial return migration, and significant improvement in education and occupational profiles among the floating population. We argue that these patterns are driven by a combination of complex domestic and international factors, including the newly released Labor Law, removal of agricultural tax, the western China development program, increased investment in education by the Chinese government, and the global financial crisis. We also discuss several challenges facing the floating population in the coming years, which include equality of educational opportunity for migrant children and adequate housing and social welfare protection for the floating population. Finally, we reflect on the future of migration research in China.

Since the reform and opening up, the large-scale migration in China has caused dramatic changes in population distribution, which has become a hot research field of human geography. Spatial pattern of population distribution has a typical character of scale dependency. Fine-scale estimation of the population distribution has been a huge challenge in the field of population geography. In China, sub-district is the finest administrative unit in official population census data. Thus, population density data at township level can be used to describe and characterize the population spatial pattern and changes elaborately, and support the optimized layout plan of Chinese population and government policy decision making. Sub-district boundaries across 13 cities in Jiangsu Province had been collected in this study. The national population census data were spatially joined to the boundary layer for population density calculation. Based on the fifth and sixth population censuses, using exploratory spatial data analysis, interpolation methods and semivariogram, the space differentiation and temporal variation of population density of all sub-districts in Jiangsu Province in 2000-2010 are explored, and further, the evolutionary mechanism of it is discussed. The results are reported as follows. In spatial distribution, the population density of Jiangsu Province was characterized by concave shaped structure, urban-rural dual structure, and core-periphery structure. Suzhou-Wuxi-Changzhou metropolitan area had the most widely dense population, and Nanjing City circle had the highest population density. In the evolution, the space differentiation of population density was becoming ever more obvious. Population density in the south of Jiangsu was generally increasing, but most towns’ population density was declining in the northern area. The variation of population density was presented spatial inequality. In evolutionary mechanism, spatial continuity and self-organization of population density have been intensified, and the spatial form of population density changed from decentralization in the initial stage to centralization. Additionally, the structural difference resulted from spatial association has become more and more obvious. The changes of population distribution were influenced mainly by policy and economic factors. First, regional strategies played a guiding role in the population distribution changes. Secondly, economic development reshaped the population distribution, and the population density had a significant positive correlation with economic density. Thirdly, location difference was the determinant. At last but not the least, physical geography difference had also affected the layout in a certain extent. This study expanded the research scale and dimension of the research in population geography research in China. The resulted population density dataset in 2000 and 2010 is expected to enrich the baseline data resources for population geography development in China.

In November, 2014, Premier Li Keqiang raised a problem about Hu Huanyong population line (hereinafter referred to as "Hu line"), when visiting the exhibition of sciences of human settlements in National Museum of China, which was called "Premier's Question" by the press. Hence, Hu line has become a highlight currently, and aroused great controversy and different views. Aiming at such dilemma of cognition, this paper gives a general review of the origins of Hu line, which was put forward by the famous population geographer Hu Huanyong in 1935, under the background of a debate on the surplus of domestic population. Based on population census data and GIS platform, the paper analyzes the change of population scale, proportion and density in both southeast and northwest sides of Hu line. The results indicate that the population urbanization and migration do not change the pattern of population distribution determined by Hu line. On such basis, the pattern that the population density of southeast part is large, while that of northwest part is relatively small will not radically change over a longer period, and the pattern that urban agglomeration is mainly located in southeast part as well. The long-term existence of Hu line depends on integrated physical geographical conditions, like climate. At the meantime, this paper argues that the core issue of the Premier's concern is solvable, by positive policy guidance and reasonable spatial organization. It is definitely promising for western China to realize a higher level of modernization and a better quality of urbanization, and central region as well.

The Hu Line for population distribution in China has been regarded as one of the greatest geographical discoveries in China because it reveals the significant spatial characteristics of China's human-land relationship. Thus, the stability and significance for spatial development of Hu Line have become a major concern after the dramatic economic and social changes since China's reform and opening-up in 1978. With the support of GIS, this paper conducts a statistical analysis and systematic investigation on the stability and spatial patterns of population growth on both sides of Hu Line by constructing the spatial database of China's census data from 1982 to 2010 and initiating a new method for identifying the spatial patterns of population growth. The findings are as follows: (1) The Hu Line has been rather stable, while a new tendency of population change has emerged. On the whole, the ratio of population on both sides of Hu Line has roughly been kept at 94:6 (the southeastern side: the northwestern side) in the last 30 years. However, the proportion of population on the southeastern side of Hu Line has been slightly decreasing, while that on the northwestern side of Hu Line has been slightly increasing, which is benefited from its higher rate of natural population growth. (2) The spatial patterns of population growth on both sides of Hu Line were quite different. The agglomeration degree of population distribution on the southeastern side of Hu Line increased greater. The areas with negative population growth rate have rapidly expanded, mainly located south of the Qinling Mountains - Huaihe River line and the northeastern China, while the areas with the fast population growth rate concentrated in the areas such as the Yangtze River Delta, the Pearl River Delta and Beijing-Tianjin metropolitan region. Thus, the spatial pattern of population growth on the southeastern side of Hu Line presented an aggregating and diffusion mode of Matthew effect. (3) The spatial pattern of population growth on the northwestern side of Hu Line could be referred as the relative balance type. In this region, the positive rate of population growth and the lower agglomeration degree of population have been identified. There were lots of ethnic groups located on the northwestern side of Hu Line, and they generally lived dispersedly but with a higher rate of natural population growth due to preferential population policy. However, there were also some areas with negative rate of population growth on the northwestern side of Hu Line and they were mainly distributed close to the Hu Line and new Eurasia Land Bridge. (4) In the future, the spatial patterns of population growth on both sides of Hu Line will continue to change. On the southeastern side of Hu Line, the capacity of population agglomeration for those small and medium-sized cities and towns should be enhanced. As for the northwestern side of Hu Line, the emphasis should be placed on promoting its urbanization and enhancing the capacity of population agglomeration for major cities.