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  • Wang Fugang, Wang Yaohui, Jiang Ming, Wang He, Pan Huilin, Wu Mingjie, Cao Yuqing
    SCIENTIA GEOGRAPHICA SINICA. 2023, 43(7): 1291-1298. https://doi.org/10.13249/j.cnki.sgs.2023.07.016

    It is of great significance to explore the formation of water resources and the water balance in Tianchi area for the protection of water resources and ecological environment. Based on the topographic and geomorphologic conditions, the special geological lithology and ring-radial fault structure characteristics of Tianchi area, the water circulation conditions and hydrodynamic characteristics of Tianchi Lake were analyzed. The "hydraulic peak elimination" effect of the ring fault structure and the water conduction effect of the radial fault are clarified, and the possibility of groundwater divide expansion in Tianchi recharge area is demonstrated. Based on the analysis of water circulation and hydrodynamic conditions in Tianchi area, and meteorological and hydrological monitoring data of Tianchi area from 2003 to 2020, the water balance of Tianchi Lake was calculated and analyzed based on the water balance method. The results show that the precipitation conditions in Tianchi area can maintain the water level balance of Tianchi Lake. The water balance of annual excretion of 3.6×107m3 of Tianchi Lake can be maintained when the precipitation is within 850-2 200 m from the outside of the surface watershed around Tianchi Lake. The average surface elevation of the water balance area is 125 m higher than that of Tianchi water surface (2 189.7 m). many ring faults and radial faults in Tianchi area. All the above faults are tensile faults. The ring faults all inclined to Tianchi which provided favorable conditions for groundwater recharge to Tianchi Lake. The formation above 1700 m in Tianchi area is mainly composed of pumice rock and pyroclastic rock, mostly of porosity structure and strong permeability. The special geological structure conditions and stratigraphic lithology in Tianchi area make the surface divide around Tianchi not coincide with the underground watershed in the groundwater recharge area. The dominant seepage conditions of the fault structure around Tianchi constitute the "peak elimination" effect of groundwater potential energy. The ring-radial fault structure and the good permeability of the stratum lithology in Tianchi area make it possible to expand the groundwater watershed. Combined the synthetic analysis result of the of water circulation and hydrodynamic conditions in Tianchi area, and meteorological and hydrological monitoring data of Tianchi area from 2003 to 2020, the water balance of Tianchi Lake was calculated and analyzed based on the water balance method. The results show that the precipitation conditions in Tianchi area can maintain the water balance of annual excretion of 3.6×107 m3 of Tianchi Lake. The distance of the water balance zone boundary is within 850-2 200 m from the outside of the surface watershed around Tianchi Lake. The average surface elevation of the water balance area is 125 m higher than that of Tianchi Lake water surface (2 189.7 m). The factors that may affect the calculation result of water balance, such as precipitation, runoff of Tianchi Lake water, calculation parameter value, condensation water amount and evaporation amount, are analyzed and discussed.

  • Yang Chen, Wang Qiang, Jin Cheng, Li Haihong, Ren Hongrun
    SCIENTIA GEOGRAPHICA SINICA. 2024, 44(5): 874-882. https://doi.org/10.13249/j.cnki.sgs.20230103

    Refinement governance is the future governance direction of the city, and it is also an important challenge for Shanghai to build an outstanding global city. Most of the existing research is based on the innovative mode and management mechanism of urban grid management, but the analysis and mining of grid management event data are still insufficient, and there is a lack of regular analysis of meteorological conditions on the occurrence of events. From the meteorological perspective, this paper uses spatiotemporal feature analysis and natural language processing methods to analyze the features of grid management event data, and uses correlation analysis and frequent pattern mining algorithms to obtain the association rules between meteorological conditions and urban management events. On this basis, the typical meteorological conditions that trigger grid management events are obtained, and the typical event knowledge graph covering meteorological conditions is constructed. The results show that the events are highly correlated with the characteristics of residents’ activities, the occurrence time of events is highly consistent with the working time, and the occurrence area also coincides with the densely populated areas of the city. There is a phenomenon of “concentrated head and long tail distribution” in the category, and a clear clustering structure can be formed in the event word segmentation, forming a co-occurrence term relation network with citizen activities as the main body. Analysis with meteorological data, municipal facilities and sanitation categories have obvious correlations with air temperature, wind-vulnerable structures are greatly affected by wind, and some illegal behaviors are also highly correlated with meteorological conditions. In addition, under specific weather conditions, some events will show an obvious tendency to occur easily. For example, events such as foundation pits, disputes, high-altitude parabolas, and river greening occur under specific weather conditions such as precipitation, low temperature, high temperature and strong wind, and strong winds will also have an amplified effect on environmental problems such as river pollution, open burning and the distribution of leaflet. On this basis, the knowledge graph technology is used to summarize and express the relationship between meteorology and urban operation, so as to form a knowledge framework for urban operation signs triggered by meteorological conditions, which is beneficial for urban operation managers to respond and deal with specific weather conditions in advance, and provide certain decision-making references for Shanghai to improve refined management measures and optimize the urban governance system.

  • Wang Shengpeng, Teng Tangwei, Hu Senlin, Li Wei
    SCIENTIA GEOGRAPHICA SINICA. 2024, 44(5): 743-753. https://doi.org/10.13249/j.cnki.sgs.20230132

    In the era of digitalization, it is of great practical significance to explore the spatial network structure of digital economy and its driving factors for promoting the construction of “digital China”. The research applied the modified CRITIC evaluation method to measure the development level of digital economy of China from 2013 to 2020, and explored the evolution characteristics and causes of the spatial network structure of the digital economy by social network analysis. The results show that: 1) The overall level of digital economy development has shown a steady upward trend, and the spatial pattern is characterized by high in the east and low in the west. 2) During the study period, the spatial connection network of the provincial digital economy in China shows a complex situation of multi-threaded and dense networking. The network density is improved, and there is no hierarchical spatial structure as a whole. 3) The economically developed regions have a significant advantage in the spatial network structure, and the connections between the western and border regions and other regions needs to be improved; the condensed subgroup spatial distribution gradually forms an orderly agglomerated distribution. 4) The spatial correlation network of digital economy is affected by the joint action of multiple factors. The level of scientific and technological innovation, government support and geographical distance have always played a significant role, while the effects of economic development level, industrial structure level and urbanization level reflect the stage characteristics by strong first and weak later. The above factors together drive the optimization and restructuring of the provincial digital economy spatial network structure in China.

  • Wang Jian, Zhang Guoyou
    SCIENTIA GEOGRAPHICA SINICA. 2024, 44(1): 1-8. https://doi.org/10.13249/j.cnki.sgs.20230881

    The future development trend of Geography has received widespread attention but opinions are divergent. Systematic analysis and elaboration of the future development trends of Geography have important theoretical and practical significance for promoting the development of Geography. The demand for Geography in socio-economic development determines the direction and possibility of Geography’s development. The effects of scientific and technological progress on Geography determines the extent and feasibility of Geography development. The inherent requirement of the development of Geography itself is the inevitability of the development of Geography. On the basis of sorting out domestic and foreign perspectives, this paper elaborates on the development trends of Geography from the perspectives of the demand for Geography from social and economic development, the effects of scientific and technological progress on Gography, and the internal logic of the discipline’s own development. With the globalization of economy, informatization of society, ecologization of civilization, and geographization of the world, Geography, as a core discipline in the study of human-earth relations, is inevitably pushed to the forefront of solving major global natural and social problems due to its intersection with natural and social sciences. It will play an increasingly important role in economic and social development and human life. The development of aerospace and remote sensing technology has greatly expanded human vision for Earth observation, promoting the possibility of global research. The development of transportation technology and information networks has led to changes in the spatiotemporal scale of the world. The development of observation technology and analytical experimental technology not only increases the quantification level of geographical analysis, but also greatly enhances the ability of Geography to serve the society and economy. Earth science is developing towards the direction of Earth system science, while Geography is developing towards geographic science and Earth surface system science. From the perspective of disciplinary development trends, the scientific, systematic, and global nature of Geography is strengthening. With the development of society and economy, the progress of science and technology, and the evolution of Geography disciplines, Geography will move towards scientific Geography, technological Geography, philosophical Geography, systematic Geography, unified Geography, global Geography, the Geography for social development, and the Geography for daily life. In the development of Geography, there is still a trend of more complex research objects, more diverse research dimensions, more diverse research scales, more diverse and integrated research methods, and more high-tech research means. It puts forward higher requirements for future geographers: they not only need to have a global perspective, the concept of interaction between people and the environment, interactions between earth spheres, regional interaction and sustainable development, but also have abilities of multi factor integration, multi perspective observation, multi-dimensional analysis, multi-scale research and integrate application.

  • Sun Bindong, Zheng Tao
    SCIENTIA GEOGRAPHICA SINICA. 2023, 43(7): 1133-1143. https://doi.org/10.13249/j.cnki.sgs.2023.07.001

    As a direct means of a "strong provincial capital" strategy, the administrative boundary expansion of provincial capital cities has attracted wide attention in recent years. In general, local governments increase their economic aggregate by developing organizational boundaries and have high enthusiasm for the expansion policy of administrative boundaries of provincial capitals. But China has been cautious about the procedure, given the risks involved and the uncertainty over its effects. The different policy considerations of the central and local governments put forward realistic demands for the performance evaluation of the administrative expansion of provincial capitals. Scientific assessments of the effect of organizational boundary expansion on provincial economic development can provide a sufficient basis for formulating relevant policies. Based on the panel data of 27 provinces in China from 1997 to 2018, this paper analyzes the economic growth effect of provincial capital city expansions after 2000 using the synthetic control method. It conducts a robustness test by using the placebo method. Then, the mechanism is analyzed from the perspective that the provincial capital city's economic scale accounts for the whole province's proportion. The empirical results show that the expansion of administrative boundaries of provincial capital cities can not significantly promote the economic growth of the whole provinces. The heterogeneity analysis shows that for provincial capital cities whose economic scale accounts for a large proportion of the province, expanding the scale of provincial capital cities by administrative means has a significant inhibitory effect on the economic development of the provinces, and the inhibitory intensity continues to grow over time. For the provinces where the provincial capital cities accounted for a relatively low proportion of the provinces' economy before expansion, it was found that the policy did not inhibit the provinces' economic growth, and the effect was not significant. The policy implication of this paper is that the expansion of the administrative boundaries of provincial capital cities has a high risk. As central cities of provinces, provincial capital cities have not played a role in promoting their economy. Therefore, the central government should carefully consider provincial capitals' administrative boundary expansion demands. The provincial capital city boundary expansion is not the only way to realize the "strong provincial capital" strategy. Considering the existing economic volume of the provincial capital city, the provincial government can carry out concussive and collaborative development through talent strategy, the construction of the metropolitan area, and other means. At the same time, subcentral cities should be cultivated to avoid "One city dominating" which might restrict the province's economic growth.

  • Wang Degen, Tang Juan, Zhu Mei, Xu Yinfeng
    SCIENTIA GEOGRAPHICA SINICA. 2023, 43(8): 1317-1328. https://doi.org/10.13249/j.cnki.sgs.2023.08.001

    The development of station areas driven by the high-speed railway dividend is out of order. The coordinated development of nodes and places has become an important path to promote the orderly construction of high-speed railway station areas and to promote each other's development. Taking 37 urban high-speed railway stations in the Yangtze River Economic Belt as examples, this paper constructs a coupling coordination degree and relative development degree model to identify the types of coupling development and spatial differentiation characteristics of high-speed railway station areas. It is found that: 1) The high-speed railway station in the Yangtze River Economic Belt can be divided into three types of coupling coordination development stages, including the running-in stage, the antagonism stage and the low-level coupling stage, exhibiting the characteristic of node lagging, place lagging and node place synchronization. 2) The types of coupling and coordination of node and place functions in the high-speed railway stations can be classified as low-coupling-node lagging, low-coupling-place lagging, antagonistic-node lagging, antagonistic-place lagging, running-in-node lagging, friction-synchronous development, and running-in-place lagging, representing low-level development, unsustainable, and to be optimized and upgraded. The spatial distribution shows significant inter-group variation in urban clusters, while cities in urban clusters are characterized by "converging centers and scattered nodes". Through this research, we can understand the current situation of functional coupling and coordination between node and place in the high-speed railway station area of the Yangtze River Economic Belt scientifically, and improve the fitness between the hub construction and function development. Besides, it can provide valuable references for promoting reasonable construction and sustainable development of the areas around the high-speed railway station.

  • Li Yuan, Liu Chengliang
    SCIENTIA GEOGRAPHICA SINICA. 2024, 44(5): 754-765. https://doi.org/10.13249/j.cnki.sgs.20230299

    Under the new round of technological revolution and industrial transformation, it is crucial to vigorously develop digital technology. This paper defines digital technologies using patent data and employs them as a measure of urban digital technology innovation. Spatial statistical and econometric methods are used to reveal the temporal evolution, spatial evolution, and influencing factors of digital technology innovation in Chinese cities. The results are as following: 1) The scale of digital technology innovation in China presents a monotonically increasing trend driven by multiple factors such as demand and policies, with the innovation scale of 7 subdivided fields maintaining a relatively stable hierarchical pattern. 2) There are significant spatial differences in digital technology innovation across Chinese cities. Its evolution exhibits a notable trend of agglomeration and diffusion coexistence, forming a digital technology innovation pattern with the Beijing-Tianjin-Hebei (BTH), the Yangtze River Delta (YRD), the Pearl River Delta (PRD) urban agglomerations as the core drivers, provincial capitals and sub-provincial cities as multi-point supporters. The spatial evolution of innovation in the 7 digital technology fields shows a similar process of diffusion from core cities to peripheral cities. The outputs of all types of digital technologies are highly concentrated in leading cities like Beijing, Shanghai, and Shenzhen, but the main city compositions for different types of digital technologies differ slightly. Some cities with overall middle-to-high rankings demonstrate relative comparative advantages in specific digital technology fields. 3) The influencing factors of digital technology innovation in Chinese cities exhibit significant spatial spillover characteristics. Knowledge bases and technology introduction are important factors promoting local digital technology innovation. However, the role of institutional factors in driving local digital technology innovation remains to be highlighted. Neighboring regions’ explanatory variables usually have a reverse impact on local digital technology innovation due to the suction effect or a unidirectional impact due to the spillover effect. The heterogeneity analysis shows that the influencing factors for the 7 digital technologies exhibit both similarities and heterogeneities.

  • Zhang Yanji, Huang Hongxiang, Lin Sheng
    SCIENTIA GEOGRAPHICA SINICA. 2024, 44(5): 766-774. https://doi.org/10.13249/j.cnki.sgs.20230320

    To compensate for the limitations of case fragmentation, inconsistent standards, misused methods of identifying city centers, and incomparable conclusions in the established Chinese polycentric spatial structure studies, this study aimed to identify all the city (sub)centers of 297 Chinese prefecture-level or above cities in 2019 by using fine-grained Landscan ambient population data and integrating spatial autocorrelation analysis with polycentric regression models. We also measured the degree of urban polycentricity using three indicators: the number of city centers, the relative distance between city centers, and the balance of center development. Then, we summarized ten types of urban spatial structure patterns based on the combination of the three polycentricity indicators mentioned above. The study identified a total of 863 centers in 297 prefecture-level or above cities in 2019, and learned the theoretical density and density gradient of each center in every city through the negative exponential function. These findings served as a comprehensive examination of the underlying base map of the polycentric structure of Chinese cities and formed the basis for subsequent longitudinal tracking analyses. Our study revealed that in 2019, monocentric, bicentric and polycentric cities accounted for approximately 29%, 20% and 45% of the total, while 5.7% of the cities remained in a dispersed pattern. We found that, except for a few cities with a dispersed pattern, the more centers, the fewer the corresponding cities. Developed, mountainous, provincial border cities, and small and medium-sized cities with an evenly distributed urban population were more likely to form sub-centers far from the main center. Larger cities with a cluster layout and smaller cities with strong counties but weak districts were more likely to develop multiple (or dual) centers with equal density and balanced influence, while the main center of circle-sprawling cities tended to dominate the population distribution in the whole region, and their spatial patterns showed a polarized trend. Our study demonstrated that the level of social and economic development was the primary factor in shaping the polycentric spatial structure of Chinese cities, and the fluctuation and variability of natural topography also objectively contributed to the growth of urban polycentricity. However, out-migration public policies such as government relocation and the construction of industrial development zones and new town did not have a significant effect on urban polycentricity. It was also difficult for road construction to effectively promote the growth of new sub-centers. Therefore, the polycentric spatial structure was the product of high-level socio-economic development rather than an artificial creation through leapfrogging planning.

  • Li Shuangshuang, He Jinping, Duan Keqin, Yan Junping
    SCIENTIA GEOGRAPHICA SINICA. 2024, 44(5): 890-900. https://doi.org/10.13249/j.cnki.sgs.20220438

    A striking warming trend has triggered extreme weather and events in the regions worldwide. Snowfall is an important indicator of climate change, changes in snowfall at different levels reflect the integrated response of global warming to the trends in key climate variables and extreme events, and significant geographical variation exists in the response pattern of snowfall in different levels across regions. Mountainous areas are highly sensitive to climate change. As an important geographical demarcation line between the north and south of China, the Qinling Mountains belongs to China’s snow-frequent belts, a sensitive area under climate change. Based on the daily data from the 72 meteorological stations, we analyzed the spatio-temporal variation of heavy snowfall and light snowfall during November-March of the following year in the south and north of Qinling Mountains from 1970 to 2018, using the method of the wet bulb temperature dynamic threshold and trend analysis. Moreover, we assessed the relationship between the snowfall and temperature in three sub-regions (Guanzhong Plain, south slope of Qinling Mountains and Hanjiang Valley). The results show that: 1) From 1970 to 2018, the number of rainless days increased, and the solid precipitation decreased obviously during November-March of the following year in the south and north of the Qinling Mountains. The number of snowfall days decreased from 8.5% to 5.2% in the previous period after 1998, and the proportion of sleet days decreased from 1.2% to 0.6%. 2) The response patterns of snowfall to climate change varies from snowfall in different levels. The snowfall amount and snowfall days of light snowfall decreased significantly, as well as intensity of light snowfall increased significantly. However, there was no clear linear increasing tendency in the snowfall amount, snowfall days and intensity of heavy snowfall, which indicates that the change of snowfall in the transition zone between north and south of China is dominated by the decrease of light snow. 3) In terms of the response to the temperature, the snowfall amount and days of light snowfall in the three sub-regions were significantly negatively correlated with temperature changes (P<0.05). Similar results were observed in the snowfall amount and days of heavy snowfall days in Guanzhong Plain and Hanjiang Valley. Meanwhile, three indexes of heavy snowfall were weakly correlated with the temperature of the south piedmont of the Qinling Mountains. Both Guanzhong Plain and Hanjiang Valley are the sensitive area the response of heavy snowfall to the temperature. The findings of this research can provide a theoretical basis for better understanding the winter climate response pattern in winter in the transitional zone between the north and south of China.

  • Shang Yuping, Zhuang Delin, Meng Meixia, Zhao Xin
    SCIENTIA GEOGRAPHICA SINICA. 2024, 44(5): 819-830. https://doi.org/10.13249/j.cnki.sgs.20220819

    In recent years, the focal point of policy attention has revolved around how to adapt to new circumstances and implement regional optimization and spatial governance. Chinese government has recently emphasized the construction of a series of well-connected suburban new cities, aiming to drive the development of polycentric urban centers and suburbanization. Consequently, the current policy emphasis is on advancing the rational layout of internal urban spaces through planning and governance, optimizing the internal spatial structure of cities. From a practical perspective, over the past two decades, the internal spatial structure of most Chinese cities has indeed undergone a transition from a single center to multicenter. While factors influencing the internal spatial structure encompass aspects like natural endowments, economic levels, public services, and transportation conditions, the research on these influencing factors has been insufficient due to data limitations and the complexity of real-world issues. Simultaneously, significant transformations have occurred in China’s highways over the past two decades. Numerous studies have confirmed their crucial role in promoting regional coordinated development and reshaping urban systems. However, there has been a prolonged neglect of the impact of highways on the internal spatial structure of cities. Against this backdrop, this study, utilizing the analysis framework of the urban polycentric spatial structure model, specifically elucidates the impact mechanism of highways on the polycentric spatial structure. Simultaneously, based on high-resolution global population distribution data from LandScan from 2001 to 2019, we constructed multiple sets of indicators for the polycentric spatial structure. Employing historical transportation routes, planned routes, and other instrumental variables, we systematically identified the impact effects of highways on the polycentric spatial structure. The results show that: 1) Polycentric spatial structure has become a primary development trend within China’s urban areas. 2) Ray-shaped or peripheral transit highways can enhance the regional advantages of peripheral areas and accelerate the transformation of spatial structure from monocentric to polycentric by agglomeration of land, development zones, enterprises, and population factors. 3) Large cities, eastern and southern cities and cities with low government financial capacity are more effective in shaping polycentric spatial structure of highways. The approach provides insights into using spatial big data technology for researching urban economics issues. The study’s conclusions supplement empirical evidence on the role of transportation infrastructure construction in promoting factor mobility and shaping spatial structures. The study holds significant policy implications for further optimizing the layout of transportation infrastructure, exploring the advantages of polycentric spatial structures, and enhancing urban economic and population carrying capacity.

  • Wang Wenqi, Liu Zhaode, Zhao Hu
    SCIENTIA GEOGRAPHICA SINICA. 2024, 44(5): 785-795. https://doi.org/10.13249/j.cnki.sgs.20221173

    Resource-based cities (RBCs) are a unique type of cities in China that have significantly contributed to China’s national economy. However, the development of RBCs has encountered challenges, and their transformation and development require urgent attention due to the depletion of resources in RBCs and the need to comply with national ecological environment protection requirements in the 21st century. To explore the hotspots and frontiers of RBCs’ transformation and development, this paper analyzes 602 CSSCI journal papers published between 1999 and 2021. The research distribution was analyzed from 3 aspects: time, journal and author distribution, using software such as CiteSpace, VOSviewer, Data source, scientific knowledge graph. The paper explores the overall situation from evolution, hotspots and frontier. The conclusions are as follows: 1) The transformation and development of RBCs has gradually entered the Chinese government’s and academia’s vision since the 1980s, but substantive research only began in 2004. 2) From a time distribution perspective, research on the transformation and development of RBCs in China can be roughly divided into 3 periods: slow exploration period (1980s—2003), high-speed growth period (2004—2013) and steady progress period (2014—); In terms of journal distribution, China Population, Resources and Environment, Economic Geography, Journal of Natural Resources, Geographical Research and Scientia Geographica Sinica are notable journals that significantly supported and led studies on RBCs. Regarding authorship, the study found that Yu Jianhui, Qiu Fangdao, Zhang Wenzhong and Jiao Huafu have had great influence and contribution in this field. 3) The study also identified 6 research frontier trends: green transformation and development of RBCs, population shrinkage of RBCs, carbon emissions of RBCs, spatial reconstruction of RBCs, innovation and transformation development of RBCs, comprehensive management of two special difficult areas of coal mining subsidence areas and independent industrial and mining areas. Finally, the study proposed future research directions in four aspects: high-quality development of RBCs, smart development of RBCs, carbon emission reduction of RBCs and spatial development of RBCs.

  • Su Hao, Li Jiake, Liu Kun, Chen Xiao, Yang Yang, Shao Zhanlin
    SCIENTIA GEOGRAPHICA SINICA. 2024, 44(5): 864-873. https://doi.org/10.13249/j.cnki.sgs.20231195

    Taking Shandong Province as an example, this article uses the net carbon sequestration accounting model and Kuznets Curve and other methods to calculate the net carbon sequestration of cultivated land use in 16 cities in Shandong Province from 2001 to 2020, and clarifies the relationship between the spatiotemporal changes of net carbon sequestration of cultivated land use and the economic and social benefits of cultivated land. The results show that: 1) From 2001 to 2020, cultivated land in Shandong Province played a huge role as a carbon sequestration, and the net carbon sequestration showing a fluctuating upward trend. In 2020, the net carbon sequestration of cultivated land use in Shandong Province increased by 33.052%, which has exceeded one-ninth of the national total. 2) The net carbon sequestration of cultivated land use in Shandong Province has exhibited significant spatial heterogeneity characteristics, presenting a spatial pattern of high in southwest and low in northeast. In 2020 alone, the high-value area of net carbon sequestration was 13.743 times that of the low-value area. 3) There exists an upward-downward-upward “N” shaped Kuznets curve relationship between the net carbon sequestration of cultivated land use and the output value of cultivated land per unit area in 16 cities in Shandong Province. 4) There is a significant inverted “U” shaped Kuznets curve relationship between the net carbon sequestration of cultivated land use and the per capita disposable income of rural residents in 16 cities in Shandong Province. The spatiotemporal changes of net carbon sequestration in cultivated land use have a significant responsive relationship with the economic and social benefits of cultivated land use.

  • Fang Yunhao, Zhao Liyuan, Gu Kangkang, Yuan Jianfeng
    SCIENTIA GEOGRAPHICA SINICA. 2024, 44(5): 796-807. https://doi.org/10.13249/j.cnki.sgs.20230300

    Taking the metro station domains in the main urban area of Hefei as an example, this study analyzed its spatial vitality characteristics based on multi-source data such as the Baidu heat index. A random forest model was used to measure the correlation of six built environment elements, including geographic location, land use, functional facilities, development intensity, accessibility, and environmental quality, with the spatial vitality of metro station domains. Furthermore, combined with the K-means clustering algorithm, this study classified the types of metro station domains and identified the deficiencies of typical station domains, and then proposed spatial vitality optimization strategies for different types of metro station domains in a targeted manner. The results show that: 1) The spatial vitality of the metro station domains in the main urban area of Hefei was higher in the evening peak than in the morning peak, and higher in the evening peak on weekdays than in the evening peak on weekends. Spatial vitality also showed a differentiation pattern of “high inside and low outside”, with vitality values decreasing from the second ring road to the outside; 2) The relative importance of each built environment variable on the spatial vitality of metro station domains during the morning, evening, and off-peak hours on weekdays and weekends was ranked in descending order: functional facilities>development intensity>geographic location>land use>accessibility>environmental quality; 3) The metro station domains in the main urban area of Hefei were divided into 4 types: mature, growing, low maturity and breeding, showing the significant clustering characteristic of “circle structure”. The mature-type station domains were clustered within the second ring road, the growing-type station domains were distributed in a circular pattern along the second ring road, the low maturity-type station domains were mainly scattered outside the second ring road in the Binhu District and the Economic Development District, and the breeding-type station domains were mainly distributed outside the second ring road in various districts of the city with a wide range. The study aims to provide policy insights for the enhancement of spatial vitality of metro station domains and low-carbon transportation strategies from a built environment perspective.

  • Liu Tianbao, Zhu Zhangwei
    SCIENTIA GEOGRAPHICA SINICA. 2024, 44(5): 808-818. https://doi.org/10.13249/j.cnki.sgs.20230247

    With the implementation of the “double reduction” policy and the advent of the post-epidemic era, the status of family education has become increasingly important. Based on the data from the 2020 questionnaire survey, this paper uses factor analysis, hotspot analysis and other methods to interpret the socio-spatial differentiation of the family education environment at the compulsory education stage and its impact on the in-home learning experience. It is found that: 1) There is multi-scale spatial differentiation in the family education environment. First, the highest degree of differentiation is found among families, reflecting the dominant role and great differences between families in constructing the family education environment. Second, the differentiation between urban circles is obvious, and the family education environment in the urban core area is more advantageous than that in urban suburbs and urban new areas. Thirdly, the differentiation and decentralized clustering of family education environments among residential and school districts also requires attention. The differentiation of the family education environment is the result of a combination of different scale factors, such as the urban environment, school districts, and residential neighborhoods and families. 2) The characteristics and spatial distribution of family education environments differ significantly among different groups. High-socioeconomic-status families provide a high-quality family education environment with the highest comprehensive score and the highest scores on all dimensions, which are concentrated in the urban core areas. Ordinary socio-economic status families provide a next best comprehensive score but weaker cultural dimensions of the family education environment, which are mainly distributed in the inner suburbs and the core of new urban areas. Low-income families provide an overall worse but better social dimension of the family education environment, which are mainly distributed at the edges of each urban circles. Low-education families provide the worst family education environment with the lowest comprehensive score, which are also mainly distributed in the outer part of each urban circles. 3) There are many factors in the family education environment that have an impact on the in-home learning experience. Among all the factors, the five dominant factors are: ‘Noise impact degree at home’ ‘Parental expectation’ ‘Study partner is your parent’ ‘Parents are able to help you solve problems of learning at home’ and ‘Number of extra-curricular books at home’, which reflect the importance of a quiet home environment, parental involvement, and a good family atmosphere for students learning at home. Urban circles had little effect on the in-home learning experience, and the dominant influencing factors were much the same across circles. The interaction of two factors significantly increased the explanatory power, indicating that in-home learning experience is influenced by a combination of factors.

  • Zhang Zihao, Wang Di, Wu Xiangwen, Li Tianrui, Zheng Zhichao, He Jianxiang, Liu Lixin, Zang Shuying
    SCIENTIA GEOGRAPHICA SINICA. 2024, 44(3): 534-542. https://doi.org/10.13249/j.cnki.sgs.20230076

    High latitude permafrost regions are the most sensitive areas to climate change. The degradation of permafrost seriously affects the soil carbon cycling process. Revealing the vertical distribution pattern of soil organic carbon in permafrost layers under different land cover types is of great significance for predicting future changes in soil carbon pools in permafrost regions. Here we select forests, forest swamps, and shrub swamps in the high latitude permafrost areas of the Da Hinggan Mountains. Soil columns (7-8 m) were collected using drilling methods to measure soil carbon (organic carbon, soluble organic carbon) under the three different land types, and further analyzed the carbon content at different depths. The results showed that as the depth increased, the soil carbon contents decreased, and the organic carbon content varied from14.55 g/kg to 95.98 g/kg (forest swamp), from 17.48 g/kg to 132.93 g/kg (forest), and from 2.58 g/kg to 396.50 g/kg (shrub swamp). There was also a high carbon content soil layer in permafrost layers. The average content of organic carbon and soluble organic carbon in the active layer soil is as follows: shrub swamp>forest>forest swamp, and the average content of organic carbon and soluble organic carbon in the permafrost layer soil is as follows: forest swamp>forest>shrub swamp. The correlation analysis revealed significant negative correlations between depth and soil organic carbon content, water-soluble organic carbon content, and soil water content in soils under forest and shrub swamp conditions. However, there was no significant correlation between depth and these indices in soils under forest swamp conditions. Additionally, pH values were significantly positively correlated with depth across all soils, while they were negatively correlated with soil organic carbon content, soluble organic carbon content, and soil water content. The coefficient of variation of organic carbon in the active layer is 30.31%-114.26%, and the coefficient of variation of organic carbon in the permafrost layer is 30.23%-192.09%. Correlation analysis showed that soil organic carbon was negatively correlated with depth and pH, and significantly positively correlated with soil moisture.

  • Sun Shuqi, Wang Bangjuan, Liu Chengliang, Liu Tong
    SCIENTIA GEOGRAPHICA SINICA. 2024, 44(5): 831-842. https://doi.org/10.13249/j.cnki.sgs.20230195

    The South China Sea Rim region is the anchor of China’s “21st Century Maritime Silk Road” initiative. It is of great significance to clarify the regional aviation connectivity and its development mechanism to promote economic and trade cooperation among countries. To this end, this paper attempts to describe the spatial evolution of the regional airline network around the South China Sea and reveal its self-organization development mechanism by constructing an aviation connectivity index, using the dominant flow and TERGM models. The results are as follows: First, the aviation hub hierarchy in the South China Sea Rim region maintains a basic stability and a certain degree of mutation. The capitals of ASEAN countries with Singapore, Kuala Lumpur, Jakarta, Bangkok, and Manila as the core, as well as Hong Kong, Guangzhou and other cities are the aviation hubs of the South China Sea Rim region. Second, the connection within the South China Sea Rim region is stable in the Indonesia-Malaysia-Thailand triangle, and it is spreading to the coastal cities of China and the Philippines in the east. The hub-and-spoke organization presents a multi-center evolution trend, following the law of regional agglomeration. Finally, the closed ternary structure has a positive effect on the air connection, the air connection of non-core cities expands rapidly, and the low-level nodes show a trend of active expansion in the process of network evolution. The urban economic development, city size, institution, culture and cooperation events all have positive impacts on air passenger transport enhancement, while geographical distance and the conflict events have a negative impact on air connections, and the overall network presents a gradual development trend.

  • Hou Chengzhi, Huang Danqing, Gui Dongwei, Lei Jiaqiang, Lu Huayu, Xu Zhiwei
    SCIENTIA GEOGRAPHICA SINICA. 2023, 43(8): 1495-1505. https://doi.org/10.13249/j.cnki.sgs.2023.08.018

    Based on the meteorological observation datasets including daily maximum temperature, daily minimum temperature and precipitation, etc. at 61 stations in the hinterland of deserts and sandy fields and surrounding area in northern China, temporal and spatial variations of climate extremes were analyzed from 1961—2019 by 24 different extreme climate indices, and their influential factors were discussed. The results show that: 1) During 1961—2019, obvious warming trend has been found in these deserts and sandy fields. Extreme temperature indices have significant changing trend with small spatial difference. The frost days, cold nights and other extreme cold events have decreased significantly, while the number of summer days, warm days and other extreme warm events have increased significantly. 2) Extreme precipitation indices have large interannual fluctuations, and they mostly increased in western deserts and decreased in eastern sandy fields. The annual precipitation in western deserts has a significant increasing trend at the rate of 5.11 d/10a, and other extreme precipitation indices such as daily maximum precipitation, moderate rain days and heavy precipitation also have also increased significantly. The annual precipitation and other extreme precipitation indices in eastern sandy fields show an obvious decreasing trend, indicating the drying trend in this region. 3) The changes in extreme temperature indices in the deserts and sandy fields of northern China show consistency with other parts of China, while the rates exceed that of most part of global land such as North America, South Africa, Australia, etc. 4) The changes in extreme low temperature and extreme cold events in eastern sandy fields are significantly correlated with the Arctic Oscillation. The weakening of East Asian summer monsoon during recent decades is the main cause for the decrease in extreme precipitation in eastern sandy fields, while the increase in extreme precipitation in western deserts may be affected by multiple factors including the Atlantic Multi-decadal Oscillation and the Pacific Decadal Oscillation.

  • Yang Yi, Yang Fengyi
    SCIENTIA GEOGRAPHICA SINICA. 2024, 44(5): 853-863. https://doi.org/10.13249/j.cnki.sgs.20220937

    With the intensification of climate change and the rapid development of the economy and society, the uneven distribution of water resources in time and space and the contradiction between supply and demand in the urban agglomeration in the Yellow River Basin have become increasingly prominent, exposing the problem of interactive stress between the ecological environment in the basin and urban development. High-quality development in the Yellow River Basin represents an advanced stage of sustainable development, and sustainable utilization of water resources in urban agglomerations creates more room for improvement in high-quality development. To actively respond to the Sustainable Development Goals proposed by the United Nations, this study takes five national urban agglomerations in the Yellow River Basin as the research object and uses the water footprint and related evaluation indices to construct an evaluation framework of the water resource utilization level oriented to Sustainable Development Goal 6. This framework is used to evaluate the water resource utilization and protection level of urban agglomerations in the Yellow River Basin. The dynamic change characteristics of the water footprint of the Yellow River Basin urban agglomeration from 2010 to 2019 are described based on the total water footprint and the proportion of each account, per capita water footprint, water footprint intensity, and water planet boundary. Global and local Moreland indices are used to describe the spatial evolution characteristics of the water footprint of the Yellow River urban agglomeration from 2010 to 2019. Based on an analysis of the spatial and temporal evolution characteristics of the water footprint of urban agglomerations in different sections of the Yellow River Basin, spatial econometric models of urban agglomerations in the whole basin, the upper and middle reaches and the lower reaches are established. This paper discusses the similarities and differences in the driving effects of socioeconomic factors on the water footprint in different sections of the basin; these factors include gross regional product, permanent resident population at the end of the year, population density, total investment in fixed assets, foreign direct investment, built-up area, total import value and total export value. The results show that the total water footprint and mean value of urban agglomeration in the Yellow River Basin increase from the upper reaches to the lower reaches in a cascade distribution pattern, with significant regional differences. The water footprint and its related indicators show an overall downward trend, but there is still a certain gap in achieving Sustainable Development Goal 6. The water footprint of urban agglomerations in the upper and middle reaches and the lower reaches presents a polarization state of “low-low” agglomeration and “high-high” agglomeration, respectively, and transitions to “low-low” agglomeration on the whole. The driving factors in different urban agglomerations have significant differences and spatial interaction effects. Therefore, countermeasures and suggestions are proposed to strengthen the radiative driving role of central cities, improve the resilience of urban water resource ecosystems, and implement differentiated water resource system management according to the comparative advantages of different urban clusters. These suggestions provide a scientific basis for strengthening watershed system governance.

  • Feng Xiaohua, Qiu Siyuan
    SCIENTIA GEOGRAPHICA SINICA. 2024, 44(5): 775-784. https://doi.org/10.13249/j.cnki.sgs.20210977

    The spatial spillover effect of urban factors plays an important role in the high-quality development of urban economy and regional coordinated development in China. Based on the rational construction of CD production function embedded in general nested spatial econometric model, this paper uses the data of 258 cities at prefecture level and above in China from 2000 to 2018 to measure the urban total factor productivity incorporating spatial spillover effect of factors to represent high-quality development of urban economy in China. At the same time, this paper uses appreciate production function embedded in general nested spatial econometric model to decompose the spatial spillover effect of capital and labour factors of specific cities and 5 major urban agglomerations, and explore the radiation driving capacity of specific cities and 5 major urban agglomerations to improve current situation of regional coordinated development in China. The results show that: 1) In terms of timing development, the overall urban total factor productivity in China has decreased slightly, but there is a gradual rising trend after 2017. In terms of spatial evolution, the total factor productivity in cities in southern and northern China has changed significantly, while the total factor productivity in eastern and western cities remains stable. 2) The result of measurement of urban total factor productivity with spatial spillover effect of factors is 0.4663 higher than that of those without spatial spillover effect of factors, indicating that spatial spillover effect of factors has a remarkable positive effect on urban total factor productivity. 3) Among the specific cities, the spatial spillover effect of factors of national central cities, and cities in the Bohai Bay, the Yangtze River Delta and the Pearl River Delta is strong, while the spatial spillover effect of factors of central and western cities is weak. Among the 5 major urban agglomerations, the spatial spillover effect of factors in Yangtze River Delta urban agglomeration is higher, while that in Chengdu-Chongqing urban agglomeration is lower.

  • Xiong Wei, Huang Meijiao, Zhong Shiyao, Luo Xiaowen
    SCIENTIA GEOGRAPHICA SINICA. 2024, 44(5): 883-889. https://doi.org/10.13249/j.cnki.sgs.20230250

    Chinese culture is centered on food. In the context of representation and non representation theory, food crosses communities, nations, and boundaries. The cognition of food comes from the mobile life practice. There are customarily such expressions as “the sweet flavor in the south, the salty flavor in the north” and “he rice in the south, the wheat in the north”, can this be seen as a metaphor for the existence of widespread food territorial stereotypes? Based on mobility, it is worth to explore whether the food regional stereotype evolves dynamically or statically. This study adopted a mixed approach to validate and measure food regional stereotypes. Applying the exploratory sequence design, this study consisted of three sub-studies. Study 1 used content analysis to initially examine the basic content of food regional stereotype. Data was crawled from Bilibili through Python, and used Rost CM6 software to analyze network text and construct semantic social network. Study 2 recruited subjects through convenience sampling and used the questionnaire survey to test the food regional stereotypes at the explicit level. Study 3 conducted Implicit Association Test to examine the existence of food implicit regional stereotype, and the experiment was designed with two within-subject variables (semantic consistency: consistency or inconsistency)×(objective area: south or north). Study 1 showed that the food regional stereotypes of the subjects were mainly reflected in the preferences of staple food and taste of the north and the south, which were specifically expressed as “sour in east, hot in west, sweet in south and salty in north”, consistent with the people’s previous cognition of food regional differences. Study 2 showed that the subjects tended to choose food words that matched the region, and formed eight specific dimensions, including: northern staple food, northern flavor, northern portion, northern dish, southern staple food, southern flavor, southern portion, and southern dish. Study 3 showed that: when the priming words of staple food, flavor, portion, and dishes were consistent with the target region (such as “noodles and the north”), the responding time was significantly lower than the inconsistency (such as “noodles and the south”). Overall, this study showed that the subjects held the regional stereotype of food in implicit and explicit levels, and the specific contents could be divided into four dimensions: staple food preference, flavor preference, portion preference and specific dishes. This study has the following implications. At the theoretical level, this stable place perception represented by food reflects the dialectical relationship between representation and non representation theory, and expands the research content of immobility under the new mobility paradigm. From the perspective of practice, this study tries to interpret commonsense food regional stereotypes in a scientific way, so as to improve the public’s understanding of food regional stereotype and reduce food cultural conflicts.

  • Li Xiaomei, Liu Xiaokang, Yan Ping
    SCIENTIA GEOGRAPHICA SINICA. 2024, 44(5): 917-927. https://doi.org/10.13249/j.cnki.sgs.20220428

    Riparian dunes are ubiquitous in the main deserts all over the world, and their uniqueness is prominently reflected in the wind-water geomorphic process. In this study, the characteristics and variations of particle size and element composition were obtained through the analysis of the particle sizes and geochemical elements in the surface sediments from the Mu Bulag River located in the Hobq Desert. For characteristics of the particle size composition, the samples collected in 2013 and 2019 were extremely fine sand and dust sand, which accounted for more than 70% with narrow kurtosis and good sorting. These results of the sediments displayed typical aeolian characteristics. However, the samples collected in 2019 presented a coarser particle size and better sorting compared with that obtained in 2013. The Si and Al were the dominant elements for chemical composition in the sediments. Considering the average chemical composition of the upper continental crust (UCC), the loss of most chemical elements in 2019 were higher than with that in 2013. The A-CN-K diagrams revealed that the chemical weathering degree was low in the surface materials of riparian dunes in the basin, indicating a weak stage of removing Na and Ca, while other elements experienced unremarkable chemical weathering or migration. As for the samples from different river sections in both 2013 and 2019, the particle sizes belonged to finer with narrower kurtosis and better sorting, and thus the aeolian characteristics were more obvious from the upper to the middle and lower reaches of the river. Compared with the average chemical composition of the UCC, the consistency of element changes trends of samples in four sections in 2013 was more remarkable. For the basin scale, the physical and chemical characteristics of surface sediments of riparian dunes in different years showed great similarities, and these results can be attributed to the influences of parent rocks and the dynamic balance in surface materials under the alternate action of wind and water.

  • Chen Tao, Gao Ge, Du Xiaohui, Chen Hua
    SCIENTIA GEOGRAPHICA SINICA. 2024, 44(5): 901-910. https://doi.org/10.13249/j.cnki.sgs.20220844

    Snow cover changes in the middle (2035—2064) and end (2070—2099) of 21st century are investigated over the Qinghai-Tibet Plateau based on the Historical data and ScenarioMIP data of the Coupled Model Intercomparison Project Phase 6 (CMIP6). Compare with the reference period (1985—2014), the mean annual snow cover days and mean snow duration decrease during the middle and end of the 21st century over the Qinghai-Tibet Plateau, and the overall reduction are more pronounce with the increase of greenhouse gas emission concentration; the reduction in the late-21st century is more pronounced compare to the mid-21st century except for the low emission scenario; Spatially, the decrease in the southeast of the Qinghai-Tibet Plateau is more severe than that in the northwest. The snow onset date is delayed and the snow end date is advanced in the middle and late 21st century, the days of former is 1.5-2.0 times that of the latter; The more greenhouse gas emissions the more days the snow onset (end) date is delayed (advanced); The changes of the snow onset date and the snow end date are more pronounced in the late 21st century. Snowfall (temperature) is positively (negatively) correlated with the annual snow cover days; Generally ,the relative contribution rate of snowfall to the annual snow cover days increases with the increase of greenhouse gas emission concentration; Spatially, snowfall (temperature) contributes more to the annual snow cover days in the southern and northern (east and west) parts of the Qinghai-Tibet Plateau. Decrease in snowfall from July to December is greater than from January to June, which may be the reason why the days of snow onset date is delayed more than the days of snow end date is advanced. There are great differences in the future snow cover changes over the Qinghai-Tibet Plateau under different scenarios, so controlling greenhouse gas emissions is crucial to slowing down the future snow cover reduction rate over Qinghai-Tibet Plateau.

  • Shen Siyi, Gu Gaoxiang, Zhang Ying, Liu Jie
    SCIENTIA GEOGRAPHICA SINICA. 2024, 44(5): 843-852. https://doi.org/10.13249/j.cnki.sgs.20220301

    Since the Industrial Revolution, the agglomeration effect brought by the high specialization and division of labor of industry has continuously guided the concentration of elements and resources to cities. The rapid expansion has resulted in an increase in gathering costs, which has triggered a series of pressures on population, transportation, housing, environment, etc. These factors lead to the decline of the attractiveness of central cities and the transfer of urban development elements to multi centers. Among them, Shanghai has been exploring the breakthrough of polycentric development for a long time since the 1980s. The Shanghai Urban Master Plan (2017—2035) issued in 2017 proposed the new town development strategy of cultivating Shanghai’s Five New Towns into comprehensive nodes with radiating and driving capabilities in the Yangtze River Delta urban agglomeration. Therefore, based on the existing polycentric research and POI data, this paper studies the spatial structure characteristics of the Five New Towns in Shanghai during the polycentric process. Compared with previous studies on urban spatial structure, this paper focuses on the spatial distribution pattern of facilities at the micro level, at the same time, explores the combination characteristics of urban spatial structure between different circles, and innovates the research methods of urban spatial structure. Based on AutoNavi Maps point of interest (POI) data, this paper divides POI into 3 types of facilities: living, production and public. Kernel Density Estimation (KDE) and Ripley’s K Function are mainly used, and a triangular trajectory model is designed to reflect the structural evolution of facility types in space. Taking the main urban area of Shanghai as a reference, based on the number, distribution and aggregation degree of different types of facilities, this paper analyzes the spatial structure characteristics and distribution rules of facilities in the Five New Towns in Shanghai, and probes into the further construction direction of the five towns. The results show that compared with the urban area, the spatial distribution characteristics of facilities in the Five New Towns are significantly difference. The new towns with long development history have obvious single center spatial structure, while those with short development history show weak multi center structure. From the high-density circles to the low-density circles, the structure of facility types in the main urban area changes little, showing the characteristics of internal “convergence of urban functions”, while the Five New Towns show the trend of gradually decreasing the proportion of living facilities and increasing the proportion of public and production facilities. Between new towns, it shows the characteristics of “convergence of expansion structure”. In the high-density circles of the new towns, the proportion of living facilities is slightly higher than that of the main urban area, reflecting certain characteristics of “sleeping town”. In the low-density circles, although the proportion of production facilities is higher than that in the high-density circle, the concentration centers of 3 facilities are highly overlapped, indicating that the concentration center of production facilities is also in the central area of the new town, and its peripheral urban functions are weak, so there is no perfect “professional function center”. Therefore, the further construction of the Five New Towns needs to emphasize the balanced and coordinated development of facilities, improve urban functions and avoid the phenomena of “bedroom town” or “ghost town”.

  • Xiao Ye, Xu Yiwen, Wu Bihu
    SCIENTIA GEOGRAPHICA SINICA. 2023, 43(8): 1410-1422. https://doi.org/10.13249/j.cnki.sgs.2023.08.010

    Based on the data from the third national land resource survey of Hainan, a comprehensive analysis was conducted using kernel density estimation, buffer and overlay analysis, logistic regression model and ridge regression model to explore the spatial pattern of villages in Hainan Island and their response to natural and socio-economic factors, and further classify the villages into different types. The study found that: 1) The distribution of villages in Hainan Island presents a spatial pattern of "dense in coastal areas, sparse in inland areas" and "intensive in eastern areas, dispersed in western areas". The village scale is generally small, and the spatial differentiation of construction land and cultivated land is overall consistent with the natural geographical differentiation base shaped by the central mountainous area and peripheral coastal area. 2) Under the background of rural transformation, the spatial distribution of villages is mainly influenced by natural environment such as altitude and slope, and economic location represented by traffic accessibility to townships, while the spatial scale of villages is more externally driven by social and economic factors such as population and GDP; relatively speaking, the distribution and expansion of construction land are strongly influenced by social and economic factors, while cultivated land still has higher dependence on natural environment. 3) Based on above, five village types were identified in Hainan Island using cluster analysis, which are mountainous ecological characteristic villages, coastal resource substitution villages, urban-rural spatial integration villages, urban-rural functional integration villages, and wide-ranging comprehensive development villages, and the corresponding development suggestions were put forward. We hope this can offer a scientific basis for "one village one policy", so as to promote rural planning and revitalization in Hainan Island, and to promote human-land harmony and high-quality regional development.

  • He Sanwei, Zhang Zhen, Qi Ziliang, Wang Haijun, Tung Chih-Lin
    SCIENTIA GEOGRAPHICA SINICA. 2023, 43(11): 1900-1910. https://doi.org/10.13249/j.cnki.sgs.2023.11.003

    Urban agglomerations are the main spatial carriers of regional development elements. It is significant to characterize the spatial structure of economic networks and the underlying mechanisms in urban agglomerations, which sheds light on regional integration and high-quality urban development. This study takes the urban agglomeration in the middle reaches of the Yangtze River in China as the case to evaluate urban competitiveness, examine spatial differentiation of intercity economic linkages and investigate the driving factors of centrality in the city network. Based on 28 prefecture-level cities in the study area, we firstly evaluate urban competitiveness based on the entropy method from four dimensions: economic development, cultural innovation, green development and liveability. Then the multi-mode traffic flows and the radiation model are combined to calculate the intercity linkages of urban competitiveness and examine their spatial patterns. Social network analysis is employed to characterize the in-degree and out-degree centrality, and the spatial econometric models are used to examine the possible driving factors of urban centrality in the economic networks. 1) The intensity of multi-mode traffic flows is stronger in three regional central cities (Wuhan, Changsha, and Nanchang) and demonstrates the spatial pattern of 'weak in the northern part and strong in the southern part divided by the Yangtze River'. The pattern of high-speed rail traffic flows is spatially unbalanced in the three provinces (Hubei, Hunan, and Jiangxi) while the pattern of passenger transport flows is more balanced among prefecture-level cities. 2) According to the intercity linkages of urban competitiveness, Wuhan and Changsha are the only two regional hub cities with strong economic radiation to peripheral cities. However, Xiangtan and Huangshi demonstrate strong economic dependence to the hub cities. Weak linkages are widely present between prefecture-level cities while strong linkages exist only among the three provincial capital cities. 3) The centrality degree in provincial capital city is much higher than other prefecture-level cities. The cities in Hunan Province have higher centrality than Hubei and Jiangxi. The spatial consistency of in-degree centrality and out-degree centrality demonstrates the bi-directional linkages between cities with the dynamic process of both agglomeration and diffusion. 4) Administrative hierarchy, economic development and globalization are the three major driving factors of out-degree centrality, while economic development and marketization are the two significant determinants of in-degree centrality. With the advent of geographic big data, and information and communication technologies, it becomes significant to examine intercity network structures from the perspective of geographic flows especially the multi-mode traffic flows. The radiation model is superior to the conventional gravity model in characterizing the heterogeneous spatial process of multiple elements guided by transport networks. Geospatial analysis and social network analysis are combined to understand the complexity of intercity economic linkages, such as spatial radiation, spatial dependence and spatial differentiation. The major findings in spatial pattern and determinants of economic networks help policy-makers and urban planners to guide regional integration, high-quality urban development and new-type urbanization.

  • Cao Liguo, Zhou Zhengchao, Chang Xiaojiao, Zeng Xiaomin, Wang Ning
    SCIENTIA GEOGRAPHICA SINICA. 2024, 44(5): 911-916. https://doi.org/10.13249/j.cnki.sgs.20220737

    Plutonium (Pu) nuclide has strong radiation toxicity and biological toxicity, which is very harmful to animals, plants and human health. Thus, it is important to analyze the level, migration and pollution history of Pu isotopes in tree rings for ecological security and phytotoxicity evaluation. Under the background of the rapid development of China’s nuclear power industry along coastal areas, it is particularly necessary to establish the background data, including the Pu activity concentration as well as isotopic composition in the tree rings collected from different regions. In the present work, based on collecting and summarizing the limited existing literature and materials, the source and deposition mode of Pu isotope in the environment are briefly described. Then, the spatial pathway of Pu isotopes entering tree rings, the radial distribution characteristics of Pu isotope in tree ring samples as well as its environmental significance are also discussed. Finally, we emphasized the importance of developing chemical analysis method for accurately determining Pu isotopes with mass spectrometry technology and the research direction of its application research of this nuclide in tree rings, which is of great significance to promote the study of Pu isotopes as a tracer in the tree ring.

  • Zeng Peng, Zeng Nujiao, Tang Tingting
    SCIENTIA GEOGRAPHICA SINICA. 2023, 43(8): 1329-1339. https://doi.org/10.13249/j.cnki.sgs.2023.08.002

    Ports are regarded as the main driving force of economic growth in urban areas. The study of port economic spatial structure is of great significance to guide the development of port areas. Based on the four urban scales of mega cities, mega cities, large cities and medium-sized cities, this paper selects 12 ports located in cities of different sizes as the research object, and then based on POI big data, uses Ripley's K function, kernel density estimation and other methods to analyze the agglomeration and distribution mode of port economy under different urban scales, and uses the industrial index method to analyze the circle characteristics of port economy under different urban scales, So as to investigate the spatial structure of China's port economy under the influence of city scale, and explore the development degree and distribution law of port economy. The results show that: 1) The number and scale of industries in most ports will show a decreasing trend as the city size increases. At the same time, due to the rigid demand of the port and surrounding residents for basic services in derivative industries, there are differences in the quantity of various industries distributed around the port. Overall, the number of POIs in derivative industries distributed around the port is significantly higher than that in related service industries; 2) Within a range of 30 kilometers of the core port area, industries of all sizes of cities exhibit agglomeration distribution characteristics due to the influence of industries such as ships, cargo transportation, and comprehensive port services. Among them, the degree of industrial agglomeration in mega cities and large cities varies more strongly with port distance than in mega cities, while the intensity of industrial agglomeration in medium-sized cities does not show a clear pattern with port distance; 3) With the gradual reduction of the city scale level, the number of industries in the circle of the port area has declined. At the same time, the derivative service industries are mainly distributed in the inner circle and the middle circle, while the related service industries are more distributed in the middle circle and the outer circle, and the phenomenon of industrial superposition is more obvious. Based on the above analysis results, the development and construction of Gangkou District in the future should pay more attention to the idea of composite industrial design, create a port economic spatial structure with the characteristics of industrial complex, and at the same time follow the concept of land intensification to promote port economic concentration and structural optimization. The port economic distribution scope should give priority to development within 30 km.

  • Han Wei, Zhao Yifu
    SCIENTIA GEOGRAPHICA SINICA. 2023, 43(8): 1340-1349. https://doi.org/10.13249/j.cnki.sgs.2023.08.003

    This paper starts from the realistic needs of implementing the Rural Revitalization Strategy, the modernization of the national spatial governance system and governance capacity. Based on the balanced development of urban and rural space and the special location characteristics of the metropolitan fringe, this paper scientifically analyzes the concept and characteristics of rural spatial governance in the metropolitan fringe, constructs the development process of rural spatial governance driven by socio-economic evolution, builds a logical analysis framework of rural spatial governance in the metropolitan fringe, and studies systematically the mechanism and model of rural space governance in the metropolitan fringe. The following conclusions are drawn: 1) With the implementation of the Rural Revitalization Strategy, urban and rural elements flow frequently. The rural areas in the metropolitan fringe have the characteristics of functional diversification, complexity of social structure and systematization of organizational structure, which correspond to material space governance, social space governance and space rights governance. 2) Governments, village collectives, enterprises and other social subjects constantly participate in the process of rural space governance, and each subject has its own unique governance behavior mechanism in rural physical space governance, social space governance and space rights governance. 3) Based on the different power allocation relationships of multiple subjects, this paper abstracts five governance models of rural space governance in metropolitan fringe, which are respectively government-led, government enterprise-joint, endogenous-driven, village enterprise-joint, and diversified-cooperation. Each space governance model has corresponding advantages and defects. Through the above studies, this paper aims to provide theoretical support and decision-making basis for sustainable development of rural space in this special region of metropolitan fringe.

  • Liu Chen, Chen Jiayan
    SCIENTIA GEOGRAPHICA SINICA. 2023, 43(8): 1371-1381. https://doi.org/10.13249/j.cnki.sgs.2023.08.006

    Since digital platforms play an increasingly important role in urban governance/management and experiences, in the past two decades, human geographers have paid active attention to how geographical knowledge is produced by the digital in the mundane and how the digital is mediating the production of space and transforming the relations between human and space. Resonating with this trend, this research explores the sociocultural patterns of daily mobilities with the assistance of digital platforms based on the concept of platform urbanism, aimed to reveal the interactions between digital subjects, platforms, and urban space during this process. The analysis in this article is based on a fieldwork in urban Guangzhou consisting of questionnaire survey, semi-structured interviews, and participant observations. The main results of this fieldwork not only provide a general portrait of digital platform use in daily travel, such as the types of platforms applied in practice and their corresponding usage frequency, but also is beneficial to better understand how digital platforms are integrated into daily mobilities in an unconscious, contingent, creative and momentary way through details like gestures, habits, emotional experience presented in the combined data. Generally, the key findings of this article have demonstrated that digital platforms have already gained broad use in daily mobilities in Guangzhou. Nevertheless, specific details about how people make use of digital platforms while planning or managing daily mobilities still vary from the demographic patterns, especially among those groups with different ages and different degrees of education. Simultaneously, the diversity and the complexity of the daily mobilities associated with digital platforms can also be attributed to the social-spatial contexts of the practice, which have an important influence on shaping different types of platform-mediated mobilities, including purposive mobilities, contingent mobilities, flexible mobilities, and the way they interweave during the process of daily mobilities. Ultimately, this article argues that daily travel is a social and digital practice that forges multiplex interactions between people, digital platforms, and urban space through two patterns: "guide" and "adaption". In the former, the use of digital platforms can guide the way in which daily mobilities are conducted by strengthening or weakening people's (digital) skills, such as collecting information, making travel plans, telling directions, experiencing and producing places. While in the latter, as a result of the highly accidental, incomplete, uncertain interactions between people, platforms, and space, failures emerging from daily mobilities would encourage users to explore their creative and resistant tactics to improve the effects of platform use. Aimed to identify the roles people, digital platforms, and urban space played respectively in mobilities in Guangzhou, this article allows us to witness how platform urbanism contributes to completing the past research on the relations between daily travel and technology, thus offering a significant insight into the further exploration of daily practice mediated by digital platforms and the construction of human-oriented smart cities in the future.

  • Lin Sainan, Feng Xin, Wang Yu
    SCIENTIA GEOGRAPHICA SINICA. 2023, 43(9): 1537-1547. https://doi.org/10.13249/j.cnki.sgs.2023.09.004

    The number and direction of China's population movements have changed substantially in the last few decades, which caused constant spatial restructuring. Migration is often a multi-stage process that migrants that migrantes may continue an onward migration after their fiyst spatial movement. However, existing studies have paid little attention to such dynamic processes. To fill this research gap, this paper analyzes the dynamic trajectory of migration and the network features of the spatial pattern, and further explores the influencing factors of the spatial choice of the onward migration by using social network analysis and the nested Logit model. The main findings are as followings: 1) The onward migration often occurs within ten years after the primary migration, with a decreasing migration distance. The majority of these onward migrants are married and tend to mirgate with family when they move again. It is also important to note that the onward migration does not always involve movement from cities in a lower hierarchy to a higher one, but presenting diversified patterns; 2) The primary migration network shows a very obvious cross-shaped diamond structure with the center of gravity to the east and south, while in the onward migration, the horizontal linkage becomes weaker, showing fewer pair cities with flows; 3) Spatial choices of onward migration are influenced by both individual and urban factors, among which the average wage in the destination city has the most significant influence, followed by individual characteristics and other urban factors. The higher the education level, the higher the administrative rank of migrants' place of origin, and the younger the onward migrants are in occupations requiring higher professional and technical knowledge and within the working age, the more they tend to flow to a Tier-one city. Based on the above empirical findings, the study further proposes relevant recommendations for different types of cities considering the characteristics of migration process: First, the cities with strong population attractiveness should actively improve facilities, public service conditions and enhance governance to increase the carrying capacity of the population. Second, different cities should be clear about the differences between themselves and other popular cities where the migrants tend to move. Given that migrants are more likely to choose destinations within the urban cluster in onward migration, the cities belonging to the cluster should utilize the population spillover effect of the core cities. They should actively adjust the industrial structure to promote the development of industries with obvious income pulling effect, strengthen the comprehensive urban governance capacity, and create ample urban amenities to attract the population. In view of the visible trend of family migration, cities should introduce corresponding policies in public services.