As a country's brand-new geographical unit in global competition and international division of labor, urban agglomeration is the product of China's new industrialization and urbanization in a higher stage, as well as the main battlefield of the "One Belt and One Road" project. Meanwhile, the development of urban agglomerations dominates not only the economic arteries, but also the future of China's new urbanization. Hence, it is of great strategic significance to promoting China's new urbanization and socio-economic development. However, a series of problems have emerged in the selection and cultivation process of China's urban agglomerations, which needs appropriate technological paths and plans to facilitate the healthy development of China's urban agglomerations from the scientific point of view. Therefore, the "High-Level Forum on China's Urban Agglomeration Development", jointly organized by the Geographical Society of China, the China's City Forum of Hundred Experts, and the Institute of Geographic Science and Natural Resources Research, CAS, was held in Beijing on December 20, 2014. After a series of heated debates, contention and discussion, nearly 100 experts attending the forum agreed that: (1) urban agglomeration plays an important role and dominates China's new urbanization. The research and development of urban agglomerations is a complex scientific issue and a very long process, as well as a natural process which cannot go against the objective laws; (2) there is a fierce debate and discussion on the basic connotation and standards of spatial recognition range, the benefit and value orientation are different at the policy level and academic level; (3) during the selection and cultivation process, "urban agglomeration disease", such as indiscriminating enclosure, unlimited sprawl, spoiling cities by excessive enthusiasm, create something out of nothing and throwing cities together in groups, should be solved as soon as possible; (4) different organization plans for the future spatial pattern of China's urban agglomerations are forming; (5) distinctive development patterns and problems do exist among urban agglomerations with different development levels, for example, the collaborative development optimization mode of Beijing-Tianjin-Hebei urban agglomeration, the expansion mode of the Yangtze River Delta urban agglomeration, the parallel development mode of the Pearl River Delta urban agglomeration, the spatial integration mode of Central and Southern Liaoning urban agglomeration, the intersecting parallels ("＃") space pattern of Harbin-Changchun urban agglomeration, the strategic integration mode of Central Plains urban agglomeration, and the balanced organization mode of Guanzhong urban agglomeration.
In this study, an economic space-dividing method for urban agglomerations is presented to theoretically explore the quantitative measurement of urban agglomeration clustering effects with two parameters (agglomeration degree and marginal agglomeration). A marginal analysis of microeconomics based on Ripley's K function of spatial point pattern analysis is also conducted. The study is novel in the aspect that economic space is divided via urban agglomeration degree and marginal agglomeration multi-scale estimation, and an optimal urban pattern is identified when marginal urban agglomeration reaches its maximum value. Finally, urban agglomeration economic spaces are determined accordingly. The Yangtze River Delta is taken as a case study to validate the proposed method. The results show that: (1) urban agglomeration degree estimates indicate that the urban spatial pattern of the Yangtze River Delta region in 2010 was random, but that of the region has shown a rapid increasing trend with the increase of scales of observation; (2) estimates of marginal agglomeration indicate that clustering effects of urban location and urban size reach peak values when city location and city size agglomeration scales reach 185 km to 173 km, respectively. At this point, the urban spatial pattern of the region achieves an optimized state; (3) results of spatial clustering analysis show that in the optimal spatial urban pattern, the Yangtze River Delta region exhibits a "core-periphery" spatial economic structure, in which highly clustered sub-agglomerations located in the Shanghai economic radiation circle form regional centers of economic development, while poorly clustered sub-agglomerations located along inter-regional administrative borders remain underdeveloped peripheral areas. This suggests that a negative marginal effect still hampers the migration of individuals across such areas.
The growth of urban space occurs not only through urban land expansion, but also from the transition of urban functional land. The transition of urban functional land can profoundly reveal the internal features of horizontal expansion of urban space, and is the spatial reflection of urban functional agglomeration and diffusion. The paper takes the central city of Changchun as a case study. ArcGIS, AutoCAD and GIS analysis methods are used in the article. Based on remote sensing images, topographic maps and land use maps covering the years of 2003, 2007, 2010 and 2012, the study analyzes the external expansion and internal renewal of urban functional land. First, the paper analyzes the overall pattern of urban spatial expansion and the change of urban land structure. Second, the external expansion and internal renewal of urban functional land are used to express the transition of urban functional land. Finally, the paper explains the internal features of urban spatial expansion and urban functional agglomeration and diffusion. The goal of this work is to provide a new and effective way to study urban spatial expansion, enriching the theoretical foundation of urban space studies. The research reveals the following points: (1) Overall, a continuous urban sprawl is still the main mode of urban spatial expansion. (2) The direction of urban spatial expansion of Changchun has phased characteristics. (3) Residential land and industrial land are the major urban functional land types in Changchun. (4) Examining three study periods reveals that external expansion and internal renewal occur in different time intervals. (5) Internal renewal and external expansion of urban functional land are important indicators of urban spatial expansion.
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.
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.
The spatial pattern of grain production in China has changed remarkably under the background of global change, industrialization and urbanization over the past 20 years. This change has great impacts on grain supply and grain market, efficiency of agricultural resources, disaster risk of agricultural production on national scale, and ecological security on regional scale as well. Current research focused on the spatial change of China's grain production based on three schemes of geographical division including North and South China division, three economic regions, and eight grain-producing bases. These schemes reflected geographical features of grain production in China. In this paper, location quotients of grain production and yield data of 2344 counties were used to analyze variations of grain production in geographical regions defined by disparity of annual precipitation, effective temperature, and landforms. The results indicated that the grain production in all the geographical regions presented an increasing trend during the period 1990-2010. Due to the spatial disparity of regional growth rate, the centre of grain production in China moved northward: from the regions with precipitation over 800 mm to those with precipitation between 400 mm and 800 mm; from subtropical zone to mid-temperate zone and warm-temperate zone; and gradually concentrated in flat plains. The results implied that the change of spatial patterns of China's grain production went against the efficient use of water and heat resources, but it was beneficial to the application of agricultural machines and the improvement of labor productivity. Given the change trends of spatial pattern of grain production, background of climate change, and the national aim of grain security, China should enhance its ability to improve efficiency of water resources and reduce the risk of natural disasters.
Swidden agriculture is an age-old, prevailing but controversial farming practice in Montane Mainland Southeast Asia (MMSEA). In the uplands of northern Laos, swidden agriculture has become the predominant land use type for centuries. The swidden system has undergone dramatic transformations since the mid-1990s. The debate on the change of swidden cultivation is linked to global critical issues of land use/cover change, biodiversity and climate change. Since the implementation of Reducing Emissions from Deforestation and forest Degradation (REDD) by the United Nations, an increasing attention has been given to swidden agriculture in the humid tropics nationally and internationally. However, very little is known or reported about the explicit spatial information of swidden agriculture and the consequences of the transitions at macroscopic scale. For the purpose of understanding the spatial and temporal dynamics of swidden system, the intensity of swidden use and fallow forest recovery in northern Laos, in this study, the swidden agriculture in 1990, 2002, and 2011 were mapped and delineated with Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper plus (ETM+) imagery (30 m) with a decision tree classification method, followed by the analysis of spatio-temporal changes of swidden agriculture. Then, annual successive TM/ETM+ images during the period 2000-2010 were used to delineate the dynamics of burning phase and cropping phase. Subsequently, the burned pixels derived in 2000 were compared with those in the following years (2001-2011) under ArcGIS 10.0 to investigate the temporal development, land use frequency and swidden cycle with time-series Landsat-based NDVI data. Finally, as the swidden cycle changed from 1 to 11 years, the fallow vegetation recovery process was studied. The results showed that: (1) From 1990-2011, the area of swidden agriculture increased by 54.98%, from 153,800 to 238,400 ha. The increased swidden cultivation were mainly found in Luang Prabang and southern Bokeo; while the decreased parts were mainly in Phongsali. (2) The swidden agriculture mainly increased at the elevations of 500-800 m, 300-500 m and 800-1000 m and on the slopes of 10°-20° and 20°-30°. More than 80% of swidden farming land was transformed from forests. (3) During the period 2000-2011, the frequency of swidden use in northern Laos was about 2 or 3 times. The intervals of any two swidden use phases ranged from 1 to 7 years. In comparison with swidden cycles and the related proportion of swidden farming in the years of 2000, 2003 and 2007, swidden cycles in most parts were shortened. (4) There was a significant correlation between fallow vegetation recovery and swidden cycle, with a correlation coefficient of 0.9698. The NDVI of regenerated vegetation could be equal to the average NDVI value of forest when the swidden cycle reaches 10 years.
This paper examines the trend of multiple cropping index (MCI) change in China at national, regional and provincial levels during 1998-2012. Based on the Theil index, it explores the spatio-temporal difference of MCI in China. In addition, a spatial econometric model is used to identify the determinants of the temporal and spatial differences of MCI from the behavior perspective. The results are summarized as follows: (1) From the national perspective, the MCP shows an increasing trend year by year. (2) At the regional level, Northeast China is the fastest growing area in terms of the MCI, whereas the central region is the slowest growing area. The central region has the highest level of MCI, while the northeast region shows the lowest level. (3) According to the Theil index value, the differences of MCI show a narrowing trend, which is mainly attributed to the differences among the four regions. (4) The MCI shows differences among China's 31 provinces, and the gap is great. (5) The proportion of non-agricultural population has a significant negative effect on the MCI, and the proportion of non-agriculture industry, agricultural policy and the per capita operating arable land have significant positive impact on the MCI. Finally, some policies are suggested to raise the level of China's cultivated cropping, such as transfering rural surplus labor, increasing the farmers' income, accelerating the transfer of cultivated land's right of use, form the scale effect of land use, further supporting and benefiting farmers in underdeveloped regions and major grain producing areas, and strengthening the role of the national agricultural policy.
China's urbanization has significantly influenced rural areas. This research, taking Fujian province as a study case, focused on rural development and its trend in coastal regions. A rurality index was introduced to measure the level of rural development. Four dimensions of rurality were considered in the index including population size, population density, extent of urban built-up area and remoteness. The results showed that rurality has a significant spatial-temporal variation. Rurality declined from 2000 to 2010. In the spatial scale, rurality increased from southeast to northwest in 2000 and 2010. The spatial pattern was roughly consistent with distribution of landforms in Fujian province. The paper divided economic development into agricultural and non-agricultural types. Economic comparative advantage was evaluated by location quotients, which showed where economic sectors were more strongly represented in particular localities than they were in the province as a whole. The location quotients and their change were used to identify rural economic development. The results showed considerable spatial clusters. We characterized four economic clusters of rural Fujian including non-agricultural mature region, non-agricultural emerging region, agricultural cluster region and traditional agricultural region. The non-agricultural economy was clustered in southeast Fujian where the rurality was the weakest and the economy was well developed. This region was taken as non-agricultural mature region. A non-agricultural economy was emerging in west Fujian, which was non-agricultural emerging region. The two economic clusters, non-agricultural mature and emerging regions, accounted for most of Fujian. Agriculture was clustered in the north of the province, and the traditional agricultural economic region was the smallest. The paper examined the coupling relationship between rurality and location quotients to illustrate characteristics of rural economic clusters. There was a significant positive correlation between rurality and location quotients. The paper finally discussed the emergence and development of a new rural type, the town village. A similar phenomenon of town villages has been observed in other coastal provinces with a high urbanization rate in China. The paper can lay scientific foundation for advancing the combination of the national strategies of new urbanization and new rural construction.
For understanding historical human-induced land use/cover change and its climatic effects, it is primary to reconstruct historical land use/cover changes with explicit spatial information. In this study, based on the historical documental cropland area at county level, we reconstructed the spatially explicit cropland distribution at pixel size of 1 km for the Songnen Plain in the late Qing Dynasty (1908AD). Two methods were used to perform the reconstructions. One method (hereafter, method I) allocated the cropland into pixels following the order from high agriculture suitability index (ASI) to low ASI within the domain of cropland area in 1959. This method was based on a hypothesis that the cropland area domain in 1959 was resulted from enlargement of the cropland area domain in 1908. The other method (hereafter, method II) allocated the cropland into pixels following the order from high ASI to low ASI within the domain of potential cropland area. The potential cropland area was created by excluding the natural woodland, swamp, water body, and mountains from the study area. Then, we compared these two methods. We found that the cropland distribution reconstructed through the two methods exhibit a similar spatial pattern. Both of the methods show that the cropland in the late Qing Dynasty (1908 AD) mostly occurred in the southern and eastern parts of the Songnen Plain. The two methods matched with each other for about 68% of the total cropland area. By spatially comparing the unmatched cropland pixels of the two methods with the settlements for each county, we found that unmatched cropland pixels by method I are closer to settlements than that by method II. This finding suggests that reconstruction with method I may have less bias than that with method II.
Farmland abandonment is a type of land use change in the mountainous areas, and this change is under rapid development. Whether farmland transfer can prevent this process or not and promote the effective allocation of land resources is a question worth studying and discussing. With the help of the previous research findings, the objective of this paper was to find out the role of farmland transfer on mitigating farmland abandonment, by using the multiple view methods with two factors, and single factor correlation analysis. The results showed that: (1) At village level, there was a significant negative correlation between farmland transfer and farmland abandonment, especially for the farmland with high grade farming conditions, which indicated that farmland transfer could prevent the abandonment of farmland with high grade farming conditions. (2) At plot level, the abandonment rate of farmland with high grade farming conditions was significantly lower than that with poor grade farming conditions. Abandoned farmland was mainly the Ⅳ grade farming conditions in the study site. (3) At village level, the role of farming conditions on farmland abandonment was insignificant. The farming condition to the difference of farmland abandonment rate at village level was not obvious. The abandonment of farmland with high farming conditions still existed, which illustrated that farmland transfer, as one of the land rental markets, was still not developed. (4) However, for the villages with higher rate of farmland transfer, there was lower abandonment rate for those high grade farming conditions, which incicated that farmland abandonment was still controlled by the improvement of land rental market. Furthermore, the function of land rental market played an important role in optimizing the utilization of farmland resources. (5) To further improve the marketing degree of land rent, the probability of farmland abandonment could be reduced. Especially, their function to farmland with high grade farming conditions was very obvious, and could avoid the waste of farmland resources with high grade farming conditions.
The land resources security appraisal of the post-earthquake reconstruction area is one of the fundamental tasks for resource-environment carrying capacity assessment. It could provide scientific reference for post-earthquake reconstruction. This paper takes Lushan earthquake as a case and identifies 3 factor groups including geological conditions and disaster risks, water and land resources conditions, and eco-environment as well as 8 factors. The appraisal model of land resources security in Lushan post-earthquake reconstruction area is constructed, and the land resources security at grid and administrative scales is analyzed with the aid of GIS spatial analysis technique. The results show that: the area of high safe class amounts to 2409.30 km2, accounting for 5.63% of the total land area, and it is mainly distributed on the eastern piedmont plains, which should be regarded as the first choice for reconstruction site selection; the middle safe class could be the supplementary choice of high safe class, and the low safe class needs to be selected for reconstruction with concrete protection measures; only 6 out of 21 counties in the stricken area have the land resource security index above 0.60, and all of them are located on the eastern piedmont plains; in the 6 hard-hit counties, only Mingshan has relatively high land resource security index (0.76), with 468.33 km2 available land for reconstruction and relatively high available land for reconstruction per capita; Mingshan should be regarded as the preferred region for large-scale population aggregation, urbanization and industrialization development for the relocation settlements of hard-hit areas. The appraisal model developed in this study is applicable to the regions with similar geological disasters, and it could also provide reference for the studies on the regions with similar geological, topographic, resources, and environmental conditions.
Under the background of accelerating global urbanization and environmental change, it is of great significance for ecological risk assessment to identify local ecological elements and processes influencing regional ecological sustainability. Ecological risk assessment has been regarded as one of the key topics in researches on integrated management of social ecological system in the view of physical geography and macro ecology. With a special focus on spatial heterogeneity and the correlations between landscape patterns and ecological processes deriving from landscape ecology, landscape ecological risk assessment (LERA) deepens this topic with a new perspective and paradigm. In this paper, through the contrast among ecological risk assessment, regional ecological risk assessment, and landscape ecological risk assessment, the connotation of LERA is clearly defined. Detailed research progresses on LERA are also discussed and focused on region selection of assessing target, landscape meaning characterization of assessing unit, paradigm uniformity of assessing method, indexation of assessing model, and weight setting of assessing index. Finally, future research prospects on LERA are proposed, including detecting ecological implication in the view of landscape process, applying the scaling concept in risk assessment, quantifying the uncertainty of assessing results, coupling nonlinear ecological model with risk threshold determination, incorporating values of ecosystem services into risk assessment, and integrating multiple ecological models through the identification of source and sink landscape process. A framework has also been constructed to illustrate the logic relationships among the prospects of LERA.
On the basis of 144719 document records from 73 Human Geography journals from SSCI database during 1900-2012, the paper conducted an integrated bibliometric analysis in respect to characteristics of document types, document outputs, keywords, authors, countries and institutions. Meanwhile, an indicator system was established to examine the features and trends of Human Geography development through comprehensive assessment towards authors worldwide. Our analysis focused on the scientific outputs, subject categories, international collaboration and geographic distribution. A multi-criteria assessment system was built to measure the contributions of 387 authors in four periods within 1900-2012. Then network phase analysis supported by Matlab and Netdraw was used to reveal the network relationships among authors, countries and institutions. It was discovered that firstly, the total amount of Human Geography documents published increased rapidly during the last century, but the proportion it held in SSCI dwindled. Secondly, the US and the UK have been playing a leading role in Human Geography research, especially institutions like University of Sheffield, UCL and University of Cambridge. Thirdly, research hotspots of Human Geography were significant in the last century, including placeness, migration, gender, tourism, planning etc., with the combination of geography with politics to be emphasized. The application of geographic information technology represented by GIS and RS aroused wide concern. The hotspot regions emerged mainly in the US and the UK, especially in some megacities. Several Chinese cities have attained incremental concentration over the last decade. In addition, leading scientists varied in different periods of the study of Human Geography, among whom Johnston R J published the largest number of articles. Moreover, a key author club has emerged led by Johnston RJ, Thrift N, Sayer A, Jackson P, Harvey D et al. With the conclusions above, this paper has shown the development characteristics and trends of Human Geography.
