With the development of modern transportation, communication and information technology, the "space of flow" based on network society has become an important theoretical frontier for studying urban spatial structure. Based on the passenger flow, material flow, fund flow and internet information flow in nine cities of the Pearl River Delta, this paper makes a comprehensive judgment on the present situation and development trend of spatial structure of urban agglomeration in this region. Research findings are as follows: (1) The present situation of urban spatial structure in the Pearl River Delta presents obvious unipolarization, and Guangzhou is the core of the delta based on the "space of flow". (2) Cities at different levels will play different roles in the future development of the urban agglomeration network. Guangzhou, Shenzhen and Dongguan play a leading role in the development of spatial structure, while Foshan, Zhongshan and other cities will assume the function of connecting transit stations. (3) The urban areas of the Pearl River Delta are well integrated. The spatial form of the radiated area of each city also indicates the functional circle and sphere of influence of each city. In the future, with the strengthening of globalization and regional integration policies, the agglomeration effect of the Pearl River Delta region will be transformed into diffusion effect, which will greatly improve the ability of the delta to absorb and allocate resources on a global scale.
High-quality talents are reshaping the world economic landscape by transcending geographic flows and driving global innovative activities. Based on the data of international student mobility, this paper draws on complex network theory to construct a multidimensional weighted directed network heterogeneity model. This model uses the GIS spatial analysis method to study spatiotemporal evolution of global talent mobility network complexity from 2001 to 2015. The results are as follows. First, the scale of the global talent mobility network is expanding rapidly, and the relationship is becoming closer and closer. In the network, both the number of talents and the choices of overseas routines are mounting. The network development has obvious small-world characteristics. However, the two levels of network differentiation are significant, and the difference is decreasing year by year. Second, the rank-size distributions of network nodes weighted degree of accession and weighted degree of output conform to the law of power distribution, showing a typical "pyramid structure" characteristics, reflecting that the global talent mobility network is controlled by a small number of pivotal node countries. The spatial patterns of the global talent mobility network are basically "from east to west, and from south to north", but the trend of mobile regionalization is gradually emerging, and the role of emerging countries attracting talents has gradually increased. Thirdly, the core-periphery structure of the global talent mobility network is remarkable. The countries in the core, strong semi-periphery and semi-periphery alternate with countries from other tiers. There is a strong mobility of relations between the core countries. The marginal countries are not connected with each other, or have weak links with each other. The talent of the marginal countries mainly flows to the core countries and semi-marginal countries. Finally, the global talent mobility network community has been significantly differentiated. The network has evolved into six associations, including American associations, EU associations, Chinese associations, South American and South African associations, Malaysian associations, and CIS associations. The scale of associations varies widely. Like the overall network, each community has a similar "pyramid structure" feature.
In China, population migration has an influence on the level of economic and social development in various regions. In 2016, the scale of migrant population reached 245 million, which became an important factor affecting population changes. From the perspective of migrant populations' destinations, with the control of population scale in some big cities in China, and the sustained economic growth in the central and western regions, the problem of population reflux is attracting more and more attention from the society. The spatial differentiation and influencing factors of migrant populations' return intention are vital issues which are urgent to be investigated. Based on data from the 2016 China Migrant Population Dynamic Survey (CMDS), this paper discusses the phenomenon about spatial differentiation of migrant populations' return intention in 279 prefecture and provincial level cities in China, using GIS spatial analysis methods such as Moran's I coefficient, Getis-Ord Gi *. Besides, we investigate the influencing factors of migrant populations' return intention. Study comes to the following conclusions: (1) Compared with the residence intention and hukou transfer intention, the return intention of migrant population in China is lower (6.17%), and the majority of migrants (74.05%) are eager to take their own home towns as refluxing destination. The scale of cities, the level of cities and the return intention of migrant population present an asymmetric "U"-shaped pattern. (2) The spatial distribution of return intention presents an aggregation pattern with marked spatial differentiation. The return intention of migrant population in Yangtze River Delta Urban Agglomeration, Beijing-Tianjin-Hebei Urban Agglomeration and Zhongyuan Urban Agglomeration is higher than that in Chengdu-Chongqing Urban Agglomeration and Harbin-Changchun Urban Agglomeration. Among the four main geographical divisions, the return intention of urban floating population in the eastern region is the highest while that of the northeast region is the lowest. South China, central-south China and part of East China are hot spots of return intention while Northeast and North China are in a weak corner. (3) The return intention is influenced by both internal factors of migrant population and external factors of in-flow area. Educational level and economic development are both internal and external factors that simultaneously play different roles in return intention. (4) Family connection, social networks, housing and economic factors of migrant population are main forces that shape the spatial pattern of return intention. Family scale in in-flow area and home-ownership rates inhibit return intention while variables such as family scale in non-in-flow area, migrant times and the family's income and expenditure proportion exert a positive influence on return intention. Based on the above conclusions, this paper proposes strategies for relevant departments on the management of migrant population.
The "Double Eleven" was shaped as an e-commerce promotion activity ("Double Eleven Shopping Carnival") in 2009. Since that, its turnover has grown rapidly. However, the sharply increased logistics service demand during this period has also exerts great pressure on China's logistics industry. Based on the methods of time-geography and data from ZJS Express, this paper makes a preliminary analysis of the tempo-spatial structure and efficiency of China's logistics service during the Double Eleven Shopping Carnival. The main conclusions are as follows. (1) In terms of the overall tempo-spatial pattern, the express circulation during the period of the Double Eleven is relatively fast and the delay is not observed at the large scale. Moreover, regions in the east have higher volume of express compared with central and northeast China, with the packages spreading from the east to the west and the northeast via the capital city in each province. (2) In terms of spatial structure, there are two major sources of expresses in each region: the short-distance and medium-distance expresses mainly come from the inside of the regions, while long-distance expresses mainly come from East China. This suggests that East China is at the core of e-commerce development and logistics services, thus has the significant function of extrovert service. (3) In terms of time structure, the majority of expresses during the period of Double Eleven are transport-dominated, with a few are warehouse-dominated and delivery-dominated. Specially, the weak transport-dominated expresses account for 73.34% of the total amount, whose average time consumption of 3 major links (i.e. warehouse, transport and delivery) are 0.505, 1.252, and 0.303, respectively. This suggests that most expresses can complete the entire distribution process in about 2 days. (4) In terms of the activity patterns, the time distribution regularities of 3 major activities (i.e. pickup, leave and delivery) are disturbed by the logistics pressure during the study period. Under the pressure, the time proportion of these activities tends to be balanced in each day. However, all the activities still maintain their original periodicity. (5) The bundle of each logistics node has drop-like and segmented features. And the processing capacity of each city presents a layered feature, which is basically in line with the level of each city in the node hierarchy. The innovation of this paper is to introduce the basic methods of time-geography into the analysis of the Double Eleven Shopping Carnival.
For a long time, the contradiction between supply and demand of cross Yangtze highway passages has been prominent. Making use of existing channels while rationally planning and building new channel infrastructures, which aims at attracting barrier-free circulation of elements has become the material basis to promote the development of cross river integration and sub-regional cooperation in the lower reaches of the Yangtze River. In this article, we analyze spatio-temporal effect on river-crossing transportation development since 2000, which is caused by the construction of cross Yangtze highway passages in the lower Yangtze region. Also, we attempt to explore the location difference and spatial characteristics of utilization among passages in the high grade road network system. By the end of 2016, the number of crossings of the Yangtze River had increased from 4 to 17. The average cross-river time of cities and counties had decreased from 7.92 h to 5.75 h. The time cost of river crossing rises in line with the shore distance, showing a little ups and downs in the process. The amplitude of cost increased slightly larger in the south than that in the north. The cost reduction rate from 2000 to 2008 was higher than that of 2008-2016. The construction of the passageway was expanded from point to surface, which enables more cities to enter the river passages within a reasonable amount of time. Cross river accessibility pattern had gradually changed from a radial structure centered in Nanjing to gradient transformation from the shore. From 2000 to 2008, high level of time compression occurred throughout the region, forming a traffic oriented mode. From 2008 to 2016, there was a slight cost reduction, but the difference in cross-river time cost in the rear area was amplified. The edge of research area remained a high level of decline which had inherent weakness of channel access. The condition of river crossing changed from single type to diversity, and the development chance for the compressed rear area was unfair, due to locational difference. With the increasing number of channel, their utilization became different. Nanjing, the hub node of river crossing in the lower Yangtze region, supports all directions of river crossing transportation using gradually improved radial high-grade highway network. Jiangyin Bridge is responsible for river crossing from the north to the south in the east part of the research area and shore area of Jiangsu province. Its unique high-grade highway network seamlessly guides the use of remote cities and counties. Wuhu Bridge and Tongling Bridge are the first bridges which jointly undertake the responsibility of river crossing in Anhui province. Subsequently, Anqing Bridge serves as the passage between cities on the west bank along the Yangtze River in Anhui province and most cities on the south bank as well as the central and north parts of Anhui. After 2008, only the Wangdong Bridge has acted as a leading role in the river-crossing transportation of north-south and northeast-southwest of the study area. In addition, the areas along the Yangtze River have been affected greatly thanks to the most direct improvement of river-crossing condition made by the new passages. With the increasing distance from shore, it is more likely to have access to the passageway quickly. Through the high grade highway, cities in a certain range can be linked to the direction of the specific passage, forming a "confluence" structure. It can be concluded that a mature and complete passageway should be a transportation corridor that includes a bridge over the river and a high grade link in the rear. The disparity of utilization originated from the difference in the positioning of each passage. Because of regional space and infrastructure construction limitations, networked efficient transportation requires establishing multiple paths to reasonably distribute river crossing in the process of advancing to the coast. "Many-to-many" river-crossing selection between passages and trunk highways can be finally formed in order to improve existing passages' traffic capacity and divert cross-river traffic pressure.
The impacts of "decoupling" global production networks on China's regional economies have become more pronounced since the 2008 Global Financial Crisis. Shanghai's computer manufacturing industries are being relocated, especially to Chongqing, an inland Chinese city. Drawing upon Shanghai's Input-Output tables and industrial databases, this study employs structural decomposition method and industrial diversity index to characterize structural changes in Shanghai's computer manufacturing industries and assess the corresponding regional economic impacts. More specifically, this study finds that: (1) As Shanghai's computer manufacturing industries have been 'locked' in the assembly process within the global value chain, the decreasing value added rates and increasing labor costs are driving firms away from Shanghai. (2) The total economic outputs of Shanghai's computer manufacturing industries decreased by 48.39 billion Yuan during 2007-2012, mainly due to shrinking domestic market and technological changes. (3) The relocation of computer manufacturing industries has limited impacts on the Pudong New Area, which has a more diverse industrial base. By contract, Minhang district and Songjiang district, with less diverse industries, are hit hard by the relocation of computer manufacturers. In order to accommodate the impacts of "decoupling" global production networks and improve regional economic resilience, Shanghai needs to become a research and development hub within global production networks, have higher labor productivity and value-added rates, as well as host a diversified industrial structure.
At present, the practice of agricultural eco-compensation in China is mainly concerned with the central vertical transfer payment to local governments, but the overall effect is not very good. Under the conditions of opening up the grain market, the flow of grain is also accompanied by the inter-regional flow of virtual cultivated land. The area where virtual cultivated land is transferred has paid too much economic, resource, and ecological costs. In order to ensure interregional fairness, it is necessary to provide eco-compensation for the virtual cultivated land flowing-out area based on the carrier of virtual cultivated land, which provides new ideas for the study of interregional agricultural eco-compensation. Therefore, this paper attempted to construct an interregional agricultural eco-compensation framework from the perspective of the flow of virtual cultivated land, and under this framework, studies were carried out on the inter-regional agricultural eco-compensation payment/compensation divisions and compensation standard measurement. The results indicate that: the basic principle of the interregional agricultural eco-compensation is to use the virtual cultivated land net flow (the difference between the input and output of virtual farmland) indicators to divide the payment/receipt area of the inter-regional eco-compensation. The sub-compartment with positive net flow should pay eco-compensation to the net outflow sub-compartment of the virtual cultivated land because the flow of virtual cultivated land occupied the land resources of other regions. A sub-compartment with negative net flow means that the sub-community's land resources are occupied by other areas through the virtual cultivated land flow and should receive eco-compensation. The amount of inter-regional agricultural eco-compensation should include the investment cost of agricultural eco-environmental protection and improvement, as well as the opportunity cost of occupying agricultural resources to be lost and uniformly collected and distributed by the management platform. After 2004, the flow of virtual cultivated land tended to be stable, which is represented by the pattern of "Shift of Farmland from South to North". The compensation area for the inter-regional agricultural eco-compensation includes 15 provincial-level areas, mainly in the northeast, north and northwest regions. The payment area includes 16 provincial-level areas, mainly in the eastern coastal areas and southwest regions. In terms of the amount of reimbursement, the average annual total value within the study period was 147.258 billion yuan, and the average annual quotas in highly compensated regions (Heilongjiang, Jilin, Inner Mongolia, and Henan) were all above 15 billion yuan. Regarding the amount of payments, the average annual value during the study period was 54.301 billion yuan, Zhejiang, Guangdong, Beijing, and Fujian in the high-paying regions had an average annual payment of more than 4 billion yuan, and Guangdong exceeded 15 billion yuan.
Based on 2000 and 2010 county-level and city-level National Demographic Census data, we applied inequality index and spatial auto-correlation analysis to specify the spatial patterns of China's high-skilled and general labor force and its variation during the decade. We also use the SLM model to further analyze the main factors that contribute to the spatial patterns and the changes of them. The results are as follows: (1) The density of high-skilled labors and general laborers was high in southeastern China and low in northwestern regions. (2) From 2000 to 2010, the high-skilled labors had been accumulating spatially while the normal labors had been dispersing. (3) The siphon effects of the high-skilled-labor clusters, which were more inclined to accumulate in coastal metropolitan area compared with 10 years ago, also enhanced during the decade. On the contrary, the echo effect of general labor clusters strengthened and attained the uniform distribution. (4) Results of spatial regression analysis showed that the level of wages, urban administrative level, the number of ten thousand college students, the coastal cities, population and spatial spillover effects in the ten years were the main factors determining the spatial distribution of high-skilled and general labor force, while the unemployment rate, high school teacher ratio, concentration of sulfur dioxide and afforestation in 2010 became the main factors influencing the two types of labor distribution. Comparing the two types of labor model, we found that the spatial distribution of the high-skilled labors was more influenced by government forces, while the spatial distribution of general laborers was influenced by market forces.
This paper analyzes the spatial growth characteristics and evolution process of the tourism enterprises in Zhangjiajie by the method of Kernel Density Estimation and Standard Deviation Ellipse. It selects the compactness index and the spatial uniform distribution ellipse of urban area to examine the urban spatial morphology evolution in Zhangjiajie. We compare the overlap area of tourism enterprises ellipse and urban space ellipse in different stages and explore the impact of the growth of tourism enterprises on urban spatial morphology. Results show that: (1) The spatial growth process and characteristics of the tourism enterprises in the study area presented a pattern of "one core and multiple poles" in the initial peirod, then turned to the "core-periphery" of the generation period and finally formed a "cluster expansion" pattern with a high density center and three sub-center linkages in the development stage. (2) The built-up area of the city showed an increasing trend, the urban space expanded continuously, and the compactness of built-up area gradually decreased. (3) In different stages, the degrees of the spatial growth characteristics of tourism enterprises impacting the urban spatial morphology are different, and present a gradual increasing trend. The conclusion is of great practical significance for re-understanding the role of tourism in the construction of urbanization.
The spatial agglomeration of manufacturing industry and its related industries is of great significance to the improvement of regional competitiveness and the shaping of regional economic spatial pattern. Based on industrial agglomeration measure index, modified gravity model and the input-output analysis, this article evaluated the spatial agglomeration pattern and spatial economy effect of the manufacturing industry and its related industries in Liaoning, and made comparsion with the whole country. The following conclusions can be drawn: Liaoning is most prominent in resources and capital intensive manufacturing industries, but during 1995-2016, the comparative advantage of Liaoning manufacturing industries in the national scale decreased; the number of related industries in manufacturing is smaller than the average of all industries in the national economy, the related industries of manufacturing in this province had a great potential of development; Shenyang, Dalian and Anshan are central cities of spatial distribution on manufacturing industry and spatial connection of manufacturing industry chain.As for most of manufacturing industries, the common agglomeration characteristics with their related industries are not obvious; in terms of economic effect, the driving effects of Liaoning manufacturing on the national economy weakened during 2002-2012, the pulling effect of manufacturing industry chain on the national economy had a large expansion space.
Industrial pollution, as one of the major issues closely related to human health, social progress and sustainable development, has drawn a great concern for global vision. This paper uses the methods of coefficient of variation, Theil index, EDSA and SDM model to analyze the spatio-temporal differentiation and the influencing factors of urban industrial pollution (UIP) in China from region-urban agglomeration-urban scales, aiming to provide reference for formulating environmental policies and promoting the development of ecological civilization. The results show that: (1) China's UIP index was declining in fluctuations in 2005-2015, but the overall inequality presented an expanding trend. The industrial pollution index respectively presented the features of "high in the east and low in the west, clustering, and grade-difference" at the regional, urban agglomeration, and urban scales, and the pollution difference of each scale was significant. The gravity center curve of UIP was biased towards the east and showed a southward shift. (2) China's UIP types had transferred from simple shift to complex shift. The pollution pattern of "Eastern>Central>Northeast>West" remained unchanged at regional scale. Urban agglomeration-scale pollution exhibited a pattern of transition from north to south and from inside to outside. Urban-scale pollution presented an evolutionary pattern of shrinking from the center to the periphery and fragmentation to concentration distribution, and it had a certain spatial dependence. (3) There were differences in the influencing factors of industrial pollution at multi-scales. Urbanization rate and industrial structure had significant effects on industrial pollution at the three scales, population density, energy intensity and environmental regulatory intensity, which all had significant impact on industrial pollution at regional and urban scales, the level of industrial development and foreign capital only had significant influence on industrial pollution at regional scale, while the level of science and technology had no significant impact on industrial pollution at the three scales. Finally, we put forward some countermeasures and suggestions to reduce the UIP emissions.
As an important basis for social equity, educational equity is a hot spot of interdisciplinary research. Therefore, urban geologists focus on the equilibrium analysis of the spatial distribution of education resources to explore the social-spatial equity of the allocation of education resources in the city. The paper aims at the particularity of the compulsory education resources being allocated under the "school-district system", and comprehensively considers the variety of the difficulties in obtaining the education resources. Based on this, it presents the social-spatial accessibility, in forms of the geographic accessibility, opportunity availability and economic affordability, to measure the difference of the spatial allocation of education resources and the difficulty in obtaining them. Taking school district of public primary and junior middle school as the space unit and residential community as the statistical object, it analyses the social-spatial accessibility of the public schools in the main city of Nanjing in 2008 and 2018, respectively. The result shows that: (1) The geographic accessibility to schools in the inner city is superior to that in the outer city, but the spatial difference is rapidly shrinking as schools are incorporated in the inner city and built in the outer city; (2) the opportunity availability to schools in the inner city is inferior to that in the outer city, and the access to the education resources in the inner city, especially the education resources of high quality, has become more scare, for the demolition in the inner city and the construction in the outer city; (3) economic affordability is associated with the grade of school, which in the top school district is the minimum, while, there is a big decline in economic accessibility, with the overall soaring housing price in Nanjing. The difficulty of obtaining high quality education resources is greatly increased, as the spatial difference of geographical accessibility is narrowing, while the social-spatial difference of opportunity availability and economic affordability is obviously expanded. Under the principle of the resources allocation of the school district system and the marketization, the economic capital has gradually become the core factor of the distribution of education resources. Having been the core competitiveness for high quality education resources, economic capital makes it easier for rich families to live in high quality school areas and accept high-quality education, which realizes intergenerational transfer of social and economic status, thus forms the interaction cycle and locking effect of education resources and social space differentiation.
Urbanization, as one of the most important ways to reduce poverty, influences rural poverty with the help of backward correlation effect, migration effect, wage effect and spillover effect. However, the empirical conclusions of urbanization's poverty reduction effectiveness were inconsistent, and even conflicting. One of the reasons is that the net poverty reduction effect of urbanization is closely related to the poor's livelihood response to urbanization. Therefore, rural households' livelihood response is an important perspective to understand the differences of poverty reduction effectiveness of urbanization. Yet unfortunately, there were few papers that have paid attention to rural households' livelihood response to urbanization, especially in the Contiguous Areas of China. In order to start a discussion, this paper, based on the survey data of 355 rural households in three typical towns, investigated the livelihood response, influencing factors and response mechanism and path of rural households under urbanization background in the Wuling Mountain area. The results showed that: (1) The farmer's livelihood response was the comprehensive reaction of the decision unit of rural settlements in the process of recombination of three basic factors (human activities and environment of the Urban and Rural Continuum. It was the result of mixture effect of background macroregulation and induction, external conditions and urban settlements' adsorption and diffusion and family factors' internal driving force. (2) The comprehensive livelihood response, livelihood space response and livelihood production response of rural households were decreasing orderly from regional central city suburbs, red tourism scenic spots of old revolutionary base areas to characteristic agriculture towns nearby county town, but the order of response of livelihood capital and means of livelihood were different, and the response intensity of each dimension was not consistent. (3) At the macro level, the regulation and induction of the evolution of the urban-rural dual system and the strategies of new-type urbanization and rural revitalization made farmers' livelihood response adapt to the national stage strategic goal. In the external condition, more gentle reliefs, closer to the county town, higher level of economic development and leisure driven urbanization of the regional central city suburbs were corresponded to wider dimension and higher strength of farmers' livelihood response. Family factors, such as incomes priority from business operation and employment, there were children or the aged family members, at least one higher degree of education family member as well as higher social capital, which made farmers' livelihood response wider and more intensively.
Rapid urbanization has brought about the adjustment of administrative divisions and the changes in urban space and boundary, as well as reconstruction of new place and place identity. This paper, taking Xiaolong village in Panyu district, Guangzhou as an example to analyzes the factors, processes and mechanism that affect suburban residents' identity reconstruction under urban expansion. Through fieldwork and by adopting qualitative method, this study finds that in the process of urban expansion, suburban residents' Hukou at Xiaolong village has been changed from farmers to city (Guangzhou) residents. Nevertheless, the residents' recognition of their new citizenship and identity is not high, with the reason that they do not see obvious improvement of their life quality after their village was incorporated into the city. Moreover, they tend to follow the historical tradition that the Xiaolong village belongs to Panyu district, which is a suburban area, instead of Guangzhou city. As a result, in spite of the administrative adjustment and the change of Hukou, suburban residents' recognition of new place identity is not strong. The paper therefore argues that place identity is a multi-dimensional and dynamic changing process, and it includes the dimensions of self-identity and perception of different places. Place identity is a selection process which involves their selection of self-identity and place, as well as their practical needs for work and life. Therefore, in the process of urban administrative division adjustment, it is necessary to pay attention to the change of suburban residents' everyday life and work, and in the meantime improving their social welfare after its integration into the city, in order to promote their new place identity and the harmonious development of city and suburban village.
Since the establishment of the county under the prefecture-level city system, the prefecture-level city of China has become the main body of the administrative division that governs the county. Although the administrative subordination relationship between the administrative divisions that govern county and the county is clear, the existing city and county in the same place and the management mode of the city of the minority autonomous prefecture. The pattern makes the spatial subordination of some cities and counties unclear, which largely stems from the long-standing attached county system in China's history. In the traditional administrative division system of China, the spatial subordination relationship between the prefecture-level city and the county under city has been relatively vague, and the two mainly rely on the establishment of a long-acting spatial connection in the attached county. After the end of the Qing Dynasty, the attached counties were canceled in large quantities. Along with the rise of urban districts and municipal districts, the traditional model of management city by the attached county which is "administrating of city-countryside unitedly" moved to "administrating of city-countryside separately". In the 20th century, the spatial subordination relationship between the prefecture-level city and the county under city gradually completed the historical succession and went towards the direction of boundary and clarification. The administrative division reform in the new era, especially the optimization of the spatial relationship between cities and counties, should fully consider the actual development of China and attach importance to the historical accumulation process of the development of administrative division in China.
The sustainable development of food in the age of environmental change and global food crisis has become a public concern and simultaneously a central research agenda that gains growing attention from scholars with diverse research backgrounds. This paper presents a systematic review on the historical evolution of what is termed 'sustainable food system' in Western geography from the 1960s up till now and based on this retrospect, a relational perspective is put forward in this paper, which focuses on the embodiment of foodways and the interconnections between body and environment. This study sums up the cardinal rationales and principles in this new paradigm of sustainable food system in two steps. First, it suggests that 'body-food relation', after a prolonged neglect in productivism agriculture geography and consumerism food geography, does function as the fundamental ontology in sustainable food system research. Above all, this relational paradigm rejects the nature-society dualism that fueled the division between food researches in physical and human geography, namely division between agriculture geography and food's cultural geography. It undermines the traditional opinion on food as a transcendental reality that can achieve sustainability in-itself through spatial fix or quality certification. In contrast, relational paradigms conceptualize food as a unity of nature and society that emerges, in a bodily-connections manner, from the process of 'things becoming food'. In this perspective, sustainable 'body-food relation', which is radically unstable and embedded in dynamic socio-natures, is the fundamental rationale in a relationally sustainable food system. Meanwhile, food is not simply a container of energy or nutrition and bodies are also not merely a passive recipient of material or meaning. Instead, they are reciprocally constituted in both material and symbolic ways and are intrinsically place-based. Put another way, sustainable food system should be ever-changing and can only be achieved through re-localized foodways. Second, this paper identifies three key principles, namely food authenticity, food security and food health, in building a sustainable food system. Such principles should not be understood as a static goal, but a fluid process in place-based socio-nature contexts. Because food is considered to emerge from the process of 'body-food encounter', these principles inevitably involve both materially and socially constructed authenticity, quantity security and cultural acceptability, physiological health and psychosocial wellbeing. Besides, relationally sustainable food system also highlights a focus on the socio-nature environment and multi-scale connotations of these principles, which further extends their meanings, such as food justice, food sovereignty, and nutrition convention. In summary, this study seeks to promote the synergies in food geography and it also calls for Chinese food geographers to be engaged in sustainable food researches through an integrative and systematic perspective.
As human activities continue to occupy ecological space in breadth and depth, ecosystems are facing potential risks from structural damage to functional disorder on the whole. Moreover, the continuous decline of sustainable supply capacity of ecosystem services has a profound impact on human well-being and ecological security. Ecological sensitivity assessment (ESA) can provide decision-making basis for controlling ecological risk and ensuring regional ecological security. However, the current methods of ESA have suffered a lot of criticisms, especially in the framework of ES-LUCC. Hence, we develop the theoretical framework and design the model of ESA to overcome the defects of existing methods based on the definition of ecological sensitivity and economic theory. In this paper, the substitution matrix of odds ratio about land use transition is considered as the sensitive factors instead of that of land area. And then ecological sensitivity index is designed by the absolute value of actual value divided by predicted value of ESV. The results show that the method of ecological sensitivity assessment designed in this paper can not only observe the regional sensitivity factors, but also identify sensitive zones effectively and it still has strong applicability and robustness in small scale. In the list of the most sensitive factors, the negatively ecological factors dominate the ecosystem services such as grassland→cultivated land due to the internal economic driving and the lack of external ecological regulation from 1990 to 2000 in Shaanxi province. However, the Grain for Green Project contributes positively ecological factors to the most sensitive factor such as cultivated land→forestland and cultivated land→grassland in the northern part of the province. Due to the implementation of many water conservancy projects in southern Qinling-Daba Mountains and Guanzhong area, the sensitivity factor coefficient of grassland→water factor is relatively high. The overall sensitivity of the study area presents the basic pattern of orderly interval "Low-High" from south to north, and shows a state of spatial agglomeration and temporal stability. The high-sensitivity areas are mainly distributed along the Qinling Mountains and Ziwuling-Huangling Mountains, and the low-sensitivity areas are mainly in the Guanzhong Plain and the central zone of Yulin city. It is urgent to adjust unreasonable land use distribution and construct an ecological screen according to ecological sensitivity for realizing harmonious coexistence between human and nature.
As a social psychology theory of group cognition and behavior, social representa-tions theory explains the psychological mechanism of how members share knowledge and communicate with each other from the perspective of group game and construction. Moreover, the theory also explains how the social representations are constructed by power and become tools of power expansion. Maps are social representation, which influence and discipline every individual in the society through the knowledge symbol system shared by groups. As a coupling between society and individuals through the macroscopic and microscopic organic links, it becomes not only the carrier of political, economic and cultural power embedding, but also the owners of power and participates in the changes and evolution of society. The power operation mechanism in the map is manifested as the power subject hiding in the "reality" constructed by the map, in fact, has realized the transformation from explicit political, economic, cultural power to the implicit discourse power. And through the discipline of individual psychological cognition, consciousness, behavior, as well as the recognition and voluntary compliance of consensual norms, the power realizes the expansion at last.
