Fan economy is a rapidly emerging business in the Internet era. However, the existing literature lacks research on fan economy from a geographical perspective. Based on the theory of network space, and taking TikTok livestreaming commerce host as an example, combined with the influencing factors of e-commerce and urban amenity theory, this study constructed an index system of influencing factors affecting the spatial distribution of Chinese livestreaming commerce host. Using location quotient, global Moran's I, and cold-hot spot spatial analysis methods, we analyzed the spatial agglomeration characteristics of Chinese livestreaming commerce host, and the geographic factors that affect livestreaming commerce host distribution through spatial regression. The results indicate that: 1) China's fan economy shows a significant spatial agglomeration, and it is highly concentrated in the eastern coastal areas, with Guangzhou and Hangzhou as the most prominent. 2) The digital economy represented by livestreaming is reshaping China's original city tier systems. Cities with entertainment media, e-commerce, and characteristic tourism (such as Changsha, Jinhua, and Lijiang), are very attractive to livestreaming commerce hosts, even more than some first-tier cities (such as Beijing and Shanghai). 3) Through spatial regression analysis, it is found that the environment for e-commerce startups and cultural tourism have a strong explanatory power for the spatial distribution of livestreaming commerce hosts. The convenience of living and the natural environment also have an important impact, and the impact of human capital is small. At the same time, the number of patents has a significant crowding out effect on livestreaming commerce hosts, and livestreaming commerce has a strong grassroots nature. This research provides detailed empirical cases for in-depth understanding of the spatial process of fan economy and its influence mechanism and provides a reference for local governments to promote the development of digital economy and formulate talent introduction policies.
With the increasing economic interaction between cities, capital flow across regions has gradually become a key factor affecting the regional economic disparities. Cross-regional enterprise investment is regarded as the micro embodiment of capital flows. It is of great significance to explore the characteristics of cross-regional enterprise investment for reducing regional economic disparities. Thus, this study examined the cross-regional investment network using the cross-regional investment data of Chinese listed companies in 1998-2018, and analyzed the characteristics of the spatial evolution of China's cross-regional investment network and its influencing factors at the national and regional levels. The results show that: the spatial agglomeration trend of node centrality in China's cross-regional investment network at the national and regional levels is obvious and the cities with high node centrality are mainly concentrated in the five major urban agglomerations. There are obvious hierarchical structure, spatial heterogeneity, and path dependence of the cross-regional investment network; the net investment inflows and outflows are mainly in the eastern region, and the investment activities tend to develop toward the central and western regions; the influence of city economic development level, industrial structure, and financial environment varies across regions and types of cities with different population scales.
Settlement pattern, an important part of the human-nature system, is the foundation of rural geography, and it has become a hotspot in geographic research. Scientific analysis and characterization of settlement patterns are significant for promoting the development of urbanization, ethnic unity, and well-off society in rural minority areas. However, there is still a lack of research on the settlement patterns of ethnic minority areas, especially in those multi-ethnic group gathered areas. This study depicted the settlement patterns of seven ethnic minority groups (including Hani, Yi, Zhuang, Han, Miao, Yao, and Dai) in the Hani Rice Terraces World Heritage area, which is a typical multi-ethnic group gathered area in the southwest of China. The results show that: 1) In terms of spatial locations, 68% of the settlements in the Hani terraced fields area are located in the west and central parts of the territory, mainly in the areas of Han, Yi, and Zhuang. 2) The ethnic settlement pattern in the Hani terraced fields is characterized by the mix of Hani-Yi, accompanied by the mix of other ethnic groups. 3) In terms of location and the environment, settlements of the seven ethnic groups have significant differences in locational and environmental characteristics such as altitude, slope, temperature, precipitation, distance to river, settlement scale, cultivated land area, distance to administrative center, and grain yields. 4) The main controlling factors of the distribution of Zhuang, Miao, and Yao settlements are economic and administrative and distance to tourism centers (86.4%, 75.3%, and 92.8%); the main controlling factor of the distribution of Yi settlements are air temperature (52.0%); and the main controlling factors of the distribution of Han, Hani, and Dai settlements are precipitation (98.7%, 52.2%, and 97.0%). 5) On the whole, the settlements of Hani terraced fields formed a three-dimensional pattern of multi-ethnic symbiosis vertically, and a multi-ethnic mosaic pattern horizontally. This research can provide a reference for the construction of new rural areas in minority regions, the optimization of settlement patterns, targeted poverty alleviation, and the construction of a well-off society in an all-round way.
Regional population decline has gradually become a new phenomenon in recent years, which has attracted extensive attention from scholars and the government. Using the national census data and 1% population sampling survey data, this study identified the population decline areas at the county level from 1990 to 2015 from a multi-periodical perspective. Based on the theoretical analysis of the driving factors of population decline, a cluster analysis has been conducted to reveal the spatial differences of the driving factors of population decline, which resulted in four typical cases of causes. The findings are as follows: First, the population decline areas have very different trajectories: while about 24% of them are characterized by fluctuating but overall decline, about 13% of them have experienced continuous decline, and about 5% of them have only experienced recent decline. Second, the fluctuating but overall decline county units were mainly distributed in the middle reaches of the Yangtze River and Gansu, Shaanxi, Jiangsu, and Fujian Provinces, and the continuous decline county units were mainly concentrated in Sichuan, Guizhou, Chongqing, and the Northeast region, and the recent decline county units were mainly concentrated in the Northeast region, Henan, and Xinjiang. Third, there are obvious regional differences in the driving factors of population decline: the county units driven by lagged economy accounted for the highest percentage, and these units were mainly distributed in the central and western regions; the county units in the Northeast region were mainly driven by the slowed economic development and the low natural growth level; in contrast, the percentage of county units only driven by the low natural growth level is relatively low, and these units were mainly distributed in the eastern region. Based on these findings, we argue that it is necessary to pay more attention to the phenomenon of population decline at the regional scale, and take targeted measures by fully considering the trend of change and driving factors of population decline in different regions.
The Alps, a typical mountain in the Eurasia Continent with mountain elevation effect (MEE), plays an important role in determining the geo-ecological pattern of Europe. The cause of the MEE is that the uplifted plateau or mountain absorbs more solar radiation. Most of the previous studies used the difference of temperature at the same altitude or base height inside and outside the mountain to quantify the MEE. However, the above methods may have some errors. This study chose the Alps as the study area and analyzed the spatial distributions of the solar radiation, temperature, and forest line in the Alps based on the collected meteorological observation data, forest line data, and digital elevation data, as well as the solar radiation data calculated by the hemispheric horizon algorithm. For the purpose of exploring the implication of MEE for the forest line, this study used solar radiation as the representation of MEE to build a forest line distribution model. The results show that: 1) The Alps has great MEE, and solar radiations of the inner mountain are much higher than that on the edge of the mountain. It is also the main reason that the temperature and the height of forest line in the inner mountain are far higher than that in the mountain edge areas. The solar radiation in the warmest month, the coldest month, and the whole year is 10-20, 20-40 and 200-400 kWh/m2 higher than that on the edge of the mountain, respectively. 2) Solar radiation can better quantify the MEE, and forest line distribution model established with solar radiations as the substitute factor of MEE has higher simulation accuracy. The accuracy of the forest line distribution model in this study (R2 = 0.736) is higher than that of the model based on temperature and precipitation (R2 = 0.522), and the contribution rate of solar radiation to forest line distribution is the highest (34.75% in January and 27.82% in July), which exceeds the contribution rates of temperature and precipitation (26.24% and 11.17%, respectively).
The Huhuanyong Line is a real portrayal of the spatial pattern of population, economic, and social development in China. It perfectly describes key characteristics of energy production and consumption. Quantitatively simulating the spatial pattern of energy consumption on the two sides of the line can provide a reference to achieve regional coordinated development. This study employed data from the China Energy Statistical Yearbook (2005-2014). We first constructed the System Dynamics Model Based on the Huhuanyong Line Energy Consumption Simulation Model (HLECSM-SD) using the
model and System Dynamics (SD) model. Then, we simulated the pattern of various energy consumptions on the two sides of the line from 2020 to 2025. Finally, this study analyzed energy consumption of China under three scenarios. The results indicate that: 1) The HLECSM-SD model fits the data well. 2) Energy consumption presents the spatial pattern of more in the east and less in the west in China. 3) The change trend of energy consumption growth rate is consistent across the two regions. The east side has a lower growth rate than the west side. 4) On the east side of the line, coal consumption has the characteristics of more in the north and less in the south. This is consistent with the spatial distribution of China's coal resources. The consumptions of petroleum, natural gas, and electricity all have the characteristics of more in the east and less in the central region. This is determined by many factors, such as resource endowment, economic development, population scale, and industrial structure of each province. 5) The influencing factors have different degrees of impact on energy consumption under different scenarios. Our findings can provide some reference for the macro decision making in the energy field.
In recent years, the spatiotemporal distribution and its hazards to republic health of air pollution in China have shown new characteristics. Using hourly air quality monitoring data for five years (2015-2019) in 332 Chinese cities, this study analyzed the spatiotemporal distribution characteristics of air quality and urban population exposure risks by different methods. The results suggest that: 1) Air quality in Chinese urban areas has improved in recent years. Ambient Air Quality Index (AQI) decreased in 303 cities (91.3%). The concentrations of PM2.5, PM10, SO2, and CO declined while the concentrations of NO2 and O3 increased. 2) The hotspots of PM2.5, PM10, SO2, and CO concentration change rates were distributed in Xinjiang and Yunnan-South China. The hotspots of NO2 concentration change rate were in the Xinjiang area and the Hetao Plain. The hotspots of O3 concentration change rate were from the North China Plain to the middle and lower reaches of the Yangtze River. The trends of air quality change in the Northwest and South China were relatively slow. 3) Nine cities were exposed to PM2.5, PM10, SO2, NO2, O3, and CO pollution, which were located in Shanxi, Hebei, and Shandong provinces; 12 cities had no exposure risks to these six pollutants, which were distributed in Xinjiang, Yunnan, Guizhou, Sichuan, Guangdong, Fujian, and Heilongjiang provinces. These conclusions are of important reference value for collaborative treatment of cross-regional air pollution and formulating spatially diffenrentiated population flow management policies in China.
Based on the data of permanent residents from six national population census of China over the period 1953-2010, this study conducted an empirical analysis on the size heterogeneity of city size distribution and the relationship between the evolution of city size distribution and city growth model, to which little attention was paid in previous studies. We selected all cities (including prefecture-level cities and county-level cities) and prefecture-level cities (city propers) alone as samples, and empirically analyzed the morphological characteristics and evolution trends of urban rank-size distribution in China and its relationship with Gibrat's Law. The results show that the main body of city size distribution in China conforms to the linear distribution of Zipf's Law. However, the two ends of the city size distribution spectrum, namely small cities and megacities, deviate from the linear distribution due to insufficient sizes. This phenomenon is not unique to China, but supported by evidence from other countries of the world. From the perspective of evolution, the city size distribution in China gradually dispersed and deviated from Zipf's Law in the early stage. However, from 2000, it began to return to the direction in line with Zipf's Law, with big cities taking the lead in 1990, which shows the coupling with the random growth of urban population in this stage and verifies the logical consistency between Zipf's Law and Gibert's Law. The findings of this study have important implications for promoting the high-quality development of city size distribution in China.
With the increasing emphasis on coordinated regional development, transport and socioeconomic developments in China have taken a new turn in recent years. Based on the present and future integrated land transport network, the trend of city network accessibility and its impact on the change of regional development patterns in China were analyzed in this study by focusing on the construction of travel circles and regional balance. The results show that the completion of the existing planning can greatly improve the accessibility of China's city network and can largely support the construction of travel circles according to the shortest travel time. By promoting the development of hub-spoke organization mode and spatial cascading order, the existing planning can guide the multi-center and networking development of spatial structure and provide a basis for the coordinated and balanced development between regions. In the future, China's transport development should continue to optimize the supply structure of transportation services and improve the ability of the integrated transport system to serve the needs of people's daily lives and production.
Urban-rural transformation (URT) is a comprehensive process with the characteristics of multi-domains and multi-levels. A scientific understanding of the concept and connotation of URT and a systematic discussion of the patterns and mechanism of URT are of great significance to solving the problems of unbalanced urban-rural development and insufficient rural development. Based on the theoretical cognition of URT, this study comprehensively analyzed the urban-rural development level and its spatial-temporal patterns in China, revealed the patterns of URT according to the coupling coordination degree of urban-rural development level, and discussed the key of urban-rural integrated development in different types of URT areas. The results show that URT is the result of the interaction between the change of urban regional system and the change of rural regional system, and its external representation is the coupling coordination state of the two different but closely related processes. From 2000 to 2018, the level of urban and rural development in all provinces of China's mainland has risen rapidly, and the coupling coordination degree of urban and rural development level has changed from being on the verge of imbalance to intermediate coordination. Spatially, the provincial coupling coordination degree of the central and western regions is significantly lower than that of the northeast and eastern regions. Accordingly, URT in China has realized the transformation from low-level urban-rural coordination to medium-level urban-rural integration, showing a spatial characteristic that provincial URT in the central and western regions lags behind the eastern areas, especially Beijing and the provinces in the Yangtze River Delta, where urban-rural development has entered or will soon enter the stage of high-level urban-rural integration. According to the features of URT in each province, URT in China can be divided into four types, that is, high-level urban-rural integrated area, medium-level urban-rural integrated area, low-level urban-rural integrated area Ⅰ, and low-level urban-rural integrated area Ⅱ. To continuously promote the development of new-type urbanization and the implementation of rural revitalization strategy, it is urgent to establish and improve the system and mechanism of urban-rural integrated development through measures such as deepening the reform, innovating the mechanism, and making up for the shortcomings.
The development strategy of industrial transfer and upgrading, coordinated development, and in-depth integration of advanced manufacturing in the Beijing-Tianjin-Hebei region put forward higher requirements for the spatial layout of manufacturing industrial clusters. Research on the change of manufacturing industry spatial pattern can provide a reference for the optimization of urban agglomerations' advanced manufacturing industries. Based on the micro-level data of industrial enterprises above designated size in the Beijing-Tianjin-Hebei region from 2000 to 2013, this study used kernal density analysis and panel data regression models to explore the characteristics and driving factors of the change of the manufacturing industry spatial pattern in the region. The results of this empirical research show that: 1) The overall spatial pattern of all manufacturing industries in the Beijing-Tianjin-Hebei region is relatively stable, and high-value areas are concentrated in the Beijing-Tianjin-Tangshan area. The regional linked development of capital-intensive industries is gaining momentum; technology-intensive industries are increasingly concentrated in a few districts and counties, and the degree of spatial autocorrelation with surrounding districts and counties has weakened as a whole; spatial expansion into nearby districts and counties and spatial transfer of labor-intensive industries appeared alternately; and the regional linked development promotes the balanced growth of manufacturing industries in various regions and narrows the development gap. 2) The manufacturing industry in the Beijing-Tianjin-Hebei region shows a clear trend of specialization and regional division of labor, and labor-intensive industries are increasingly spreading to the periphery of the central cities and the counties in the central and southern areas of the region. Capital-intensive industries are concentrated in the industrial belt on the west coast of the Bohai Sea, the industrial output value of the peripheral areas of the region has increased significantly, and technology-intensive industries are gathered in the Beijing-Tianjin high-tech industrial belt. 3) The key driving factors of the three types of manufacturing industries are different. Labor-intensive industries are affected by investment and transportation accessibility. Capital-intensive industries are highly dependent on local market size and investment, and are insensitive to transportation accessibility. Technology-intensive industries are mainly constrained by transportation accessibility and wage levels. The three types of manufacturing industries are obviously affected by local fiscal expenditures.
Since the marketization of China's housing system, urban residents' housing adjustment through making residential moves has become relatively frequent. Residential mobility, as the micro-mechanism of urban space differentiation and restructuring, has been extensively studied in urban geography and housing studies. However, the existing literature mainly focuses on the motivation underlying residential mobility and its impacts on individuals/families and urban space. Comparatively, the location changes before and after residential moves have received scant attention in previous studies. This study adopted the perspective of life course and time geography to depict the residential trajectories of Shanghai residents and explore the influencing factors of location choice in residential mobility. The data used for the empirical analysis were drawn from the 2018 "Shanghai Resident Housing and Living Space Survey", which adopted the stratified and multi-stage probability proportion to size sampling. A retrospective survey was conducted, allowing us to obtain information on the respondents' sociodemographic information and their residential trajectories. The results reveal that the dominant type of location change is outward move across the ring roads. Nevertheless, the variations in location choice between cohorts, local population and migrants, and renters and owners of properties are evident. Compared with the older cohorts, younger cohorts generally make residential moves at earlier ages, and many of them move from the central areas to the suburbs. Different from the local population, migrants' residential mobility is more constrained in terms of the timing of making residential moves and their location choice. Furthermore, this study shows that age, location of workplace, and housing tenure all significantly affect location choice in making residential moves. Specifically, the older cohorts concentrate in the central areas before as well as after a residential move. Commuting distance plays a major role in affecting people's choice of residential location, and owning an automobile has insignificant influence. A transition into homeownership is often associated with a change to an advantageous location.
Geopolitical setting research is the focus and hot spot of political geography in China. Significant progress has been made in the areas of conceptual framing, connotation, analytical framework, spatial differentiation, system simulation, and so on. However, the study of geopolitical setting in geopolitical-strategic intersection areas has not been fully developed. This study constructed an evaluation model of geopolitical setting in geopolitical-strategic intersection area based on the space and power of geopolitical strategy, by combining the theories of geopolitical setting and geopolitical potential in political geography, and realism, liberalism, and constructivism in international relations, and by giving consideration to the philosophy of inter-subjectivity. This study also took Ukraine as an empirical study to verify the reliability of the model. The results show that: 1) On the whole, Ukraine's geopolitical setting tends to be improving, but it fluctuates violently, and will be intermittently turbulent in the future. 2) Under the influence of historical and cultural origin, military material power, strategic investment willingness, economic interdependence, geographic and spatial distance, and other factors, Russia has maintained a large geopolitical potential advantage in Ukraine. 3) Germany's geopolitical potential in Ukraine fluctuates greatly from year to year, and is on the rise in recent years due to the influence of geoeconomic factors. The geopolitical potential of France and the United States in Ukraine has been lower than Russia and Germany. In the future, the geopolitical potential of France will increase slightly, while that of the United States will decrease. The geopolitical setting evaluation model of geopolitical-strategic intersection area proposed in this study has been verified by historical data, and the assessment results have a high fitting degree with the evolution of domestic political situation in Ukraine. The model has reasonable reliability, and can provide reference for the geopolitical setting evaluation in other geopolitical-strategic intersection areas.
Strategic emerging industries are important support for national economic development. It is of great significance to explore the spatial-temporal evolution characteristics and influencing factors of the development level of related industries in Northeast China to promote regional economy and industrial innovation development. Using the Tianyancha software to extract the A-shares and the new over-the-counter market listed company data in 2009, 2014, and 2019 for Liaoning, Jilin, and Heilongjiang provinces and applying the methods of Markov chain, spatial autocorrelation analysis, and geographical detector model, this study explored the spatial and temporal change of strategic emerging industry development level and analyzed its influencing factors. The results show that: 1) The development level of strategic emerging industries in Northeast China is constantly improving, and the growth rate is slowing down. All types of strategic emerging industries in Northeast China have achieved leap-forward development, while the industries at a high development level have achieved steady development. 2) The development level of strategic emerging industries in Northeast China is characterized by a "polar area" in the central part of the region and a "S-shaped polar zone" in the south. Spatial agglomeration is weakened, and the spatial differentiation of the provinces is gradually enhanced. The spatial centers of gravity of development level of various industries have shifted southward, with both diffusion and agglomeration effects. 3) Different factors play different roles, and multiple factors jointly affect the change of the development level and spatial pattern of strategic emerging industries in Northeast China.
The scientific and reasonable siting of administrative centers directly affects the efficient allocation of resource elements, equality of basic public services, coordinated and balanced regional development, and modernization of national governance system and governance capacity. This study used spatial analysis and the difference-in-differences (DID) model to analyze the basic characteristics, mechanism, and economic effects of administrative center relocation in China since the reform and opening up in 1978. The results show that in terms of relocation characteristics, the higher the administrative level, the longer the relocation distance is, and the relocation is mainly concentrated after 2000, especially in North China, while the relocation distance in western China is generally much longer than that of other regions. In terms of relocation effects, the growth rates of population, economy, and construction land around the new administrative centers are obviously faster than that of the original administrative centers. On the whole, the relocation of administrative centers plays a certain role in promoting economic development, but there is also a clear spatial heterogeneity. In terms of the factors and mechanism of influence, the process is mainly influenced by the restriction of resources and environmental conditions, the promotion of old city planning and reconstruction, the guidance of the development and construction of new areas, the reform of the administrative system, and urban development strategies. The relocation of administrative centers is usually the result of the joint action of multiple factors.
Assessing the characteristics of landscape multifunctionality change in rapidly urbanized areas is critical for understanding resource allocation and optimization under the background of rural-urban development and transformation and for formulating reasonable regional land management and planning policies. This study took Suzhou City, the most prominent representative city in the urbanization process in the Yangtze River Delta Economic Zone, as the research area. Six landscape multifunctionality indicators are selected, including residential support, food supply, habitat maintenance, water conservation, climate regulation, and soil retention. Based on the 1 km landscape units, change in hotspots of regional landscape multifunctionality and trade-off co-evolution relationships were analyzed through spatial analysis, self-organizing feature maps (SOFM) network model, and other methods. The research shows that: 1) Affected by urban expansion, landscape multifunctions in Suzhou during 2000-2015 were dominated by the spread of residential support functions. Other landscape functions represented a differentiated shrinking trend, of which the function of food supply and habitat maintenance was weakened most significantly, and the spatial distribution characteristics of the three regulatory functions were consistent. 2) Landscape multifunctionality in Suzhou has gradually increased over time, and its high-value (>2) areas are concentrated in forest, grassland, and farmland areas. The spatiotemporal change of regional landscape multifunctionality varied from strong to weak and gradually stabilized under the influence of socioeconomic development, the hotspots of change were mainly distributed in rural areas and rural-urban junctions, and the cold spots are mainly based on ecological spatial agglomerations. 3) Trade-off relationships between landscape multifunctions during the study period did not change over time, but there is a volatile change in trade-off degrees. Combining the features of multifunctional trade-offs and the changing pattern of multifunctionality hotspots, Suzhou City can be divided into eight types of dominant landscape functions and four types of rural-urban development zones in landscape units and township administrative units. Overall, the advantages of landscape multifunctionality in rapidly urbanized areas of the Yangtze River Delta present a circular spatial migration process of "city → near suburbs → far suburbs → rural areas". However, land use diversifications mapped out by the multifunctionality will inevitably lead to more land use conflicts. Policymakers should consider the design and implementation of landscape management or land use policies from a multi-scale spatiotemporal coupling perspective.
Achieving sustainable poverty alleviation and establishing a prevention and control mechanism for return-to-poverty in extreme poverty rural areas is a realistic requirement in the post-2020 era. It is also a key link between precision poverty alleviation and rural revitalization. Taking Chengkou County of Chongqing Municipality—an area of strong ecological fragility and concentrated continuous poverty—as the research area, and based on the poverty alleviation sustainability measurement model, obstacle degree model, and minimum variance model, this study explored the spatial differentiation of multidimensional poverty alleviation sustainability and the return-to-poverty risk models for 60 villages and 1950 farming households in the area. The study found that: 1) The sample villages' poverty alleviation sustainability distribution generally showed a "gourd-like" structure where the front end is narrow and the middle part protrudes. The multidimensional poverty alleviation sustainability in the area is generally low and of different degrees. 2) The return-to-poverty risk in Chengkou County can be divided into four models and 11 types, dominated by diversified integration of various resistance factors. Human capital, development opportunities, and other factors related to sustainable income growth, dynamic anti-risk capability, and endogenous drives of farmers have gradually become the focus of poverty reduction and control of return-to-poverty at this stage. 3) Local governments should give equal priority to alleviating poverty, improving the sustainability of poverty alleviation, and preventing return-to-poverty. At the same time, improve people's ability to resist risks and develop a network for preventing return-to-poverty of vulnerable groups with specific policy in each village.
Taking the Yangtze River Delta as the research object, this study established the correlation model and coupling degree model for evaluating the mechanism of interaction between urban land expansion and ecological environment effects by using grey correlation analysis method. It explored the pattern of temporal and spatial variation and coupling degree characteristics of urban land expansion and ecological environment effects and change, and analyzed the interactions between the two systems. The results show that: 1) The index of urban land expansion in the Yangtze River Delta has been increasing, and the socioeconomic development and land use development have played a significant positive role. Socioeconomic development imposes a demand for greater urban production and living space and higher environmental quality. The increase of construction land area, the high-intensity expansion and the decrease of population density are all important reasons for the increase of urban land expansion index. 2) The overall performance of the regional ecological environment quality is stable, and the ecological environment effect is reflected in its spatial differentiation, with obvious characteristics of spatial and temporal change. The ecological environment quality of the cities in Zhejiang Province is significantly higher than that of Shanghai Municipality and Jiangsu Province, which is closely related to the regional environmental carrying capacity, the construction of pollution control facilities, and the propagation of ecological protection concepts. 3) Most cities have low coupling degree between urban land expansion and ecological environment effect, and the relationship between the two systems is in a state of imbalance. In the process of urbanization, land expansion tends to be low-density and decentralized, which strongly threatens the ecological security and environmental quality and lead to the increase of spatial disparity between urban land development and ecological environment protection. 4) There is a strong interaction between the elements of urban land expansion system and ecological environment system in the Yangtze River Delta, and the forces of each element are slightly different. The stressing effect of urban land expansion on ecological environment is gradually increasing, while the restraining effect of ecological environment on urban land expansion is decreasing.
Firms spatial expansion is of great significance to enterprise efficiency and regional coordinated development. Based on the data of listed manufacturing firms in Beijing and their subsidiaries from 2009 to 2018, this study examined the enterprise spatial expansion model through the changes of spatial distribution of subsidiaries, and analyzed the change of the distance between headquarters and subsidiaries brought by expansion. Furthermore, the dynamic panel measurement method was used to empirically test the impact of the change of geographical distance and economic distance between headquarters and subsidiaries on the efficiency of manufacturing enterprises with different expansion modes. The study found that: First, during the study period, the scale of expansion of the sample listed manufacturing firms in Beijing was relatively large, and the spatial expansion mode has changed from hierarchical diffusion to a combination of hierarchical diffusion and contagious diffusion, with contagious diffusion as the dominant mode. The geographical distance between headquarters and subsidiaries showed an upward trend, and the economic distance first decreased and then increased. Among these firms, technology-intensive firms and non-state-owned firms tend to experience hierarchical diffusion, while non-technology-intensive firms and state-owned firms tend to undergo contagious diffusion. Second, for the firms with contagious diffusion as the main expansion mode, geographical distance between headquarters and subsidiaries was negatively correlated with firm efficiency, but the efficiency of firms that did not take contagious diffusion as the main mode of expansion was not affected by geographical distance. Third, regardless of firm expansion mode, economic distance between headquarters and subsidiaries was positively correlated with firm efficiency. Therefore, different types of manufacturing firms should choose different expansion strategies.
Located on the southeast edge of the Qinghai-Tibet Plateau, the Nyainqêntanglha Mountains are an important area of mountain paleoglaciers. Affected by the monsoon, the glacier change characteristics in each region are obviously different. Based on Landsat TM/ETM+/OLI data, ASRTMGDEM and meteorological data, using the method of threshold ratio, visual interpretation, VOLTA model and combined with field investigations, this study analyzed the advance and retreat conditions, area changes, ice reserves changes, and glacier changes deal with climate change of modern glaciers in the middle Nyainqêntanglha Mountains from 1990 to 2020. The results show that: 1) During the period 1990-2020, the elevation of the five studied glaciers (G094383E30581N, G094574E30563, G094637E30633N, G094770E30626N and G094928E30607N) gradually increased. The glacier area and ice reserves decreased by 30.38 km2 and 64 km3 respectively. 2) The ice reserve of each glacier decreased by 0.14-1.92 km3, with an overall change rate of 0.40%·a-1. By 2020, the reserves of the above glaciers will account for 0.70, 0.99, 0.98, 0.91 and 0.82 in 1990 respectively, which shows that the larger the scale of the glacier, the smaller the change is in a short time. 3) Through the analysis of meteorological data, during 1990-2020, the average temperature change rate of the study area was 0.51 ℃, which shows that the overall glacier change was dominated by the temperature rise. It is predicted that the glacier change in the future will be controlled by the temperature and show a trend of accelerated retreat. 4) The regional comparative study showed that the glacier area change in the Nyainqêntanglha Mountains is generally in a state of retreat, but the characteristics of glacier change in different regions are obviously different. The research on glacier ice reserves in the region is relatively weak, and the simulation results of different research methods for the same glacier ice reserves have large errors, with the relative error range of 34.45%-115.49%.