Border areas are important national security buffer zones and vulnerable areas under the influence of multiple power spaces. Scientifically summarizing the development process of border research will help clarify the context of border research and provide scientific support for realizing a stable border with security and sustainable development. This study was based on data of academic publications on border research in the fields of human geography in China from the China National Knowledge Infrastructure (CNKI) and Web of Science (WoS). With the help of the scientific knowledge map method, the basic characteristics of China's border research process, trends, and hotspots since 1990 were analyzed. The study found that China's border research has experienced an "open exploration-social construction-strategic guidance" development process. The research hotspots have gradually shifted from the northeast to the southwest, and "border trade", "border tourism", "border port", and "Belt and Road" are the four main keyword clusters. The main contents of border research include border trade and development and opening-up, border tourism resource development, social construction and harmonious development, border ports and urban functions, as well as geographical environment and border security. At present, China's border research is still insufficient in terms of exploring the patterns and quantitative analysis. On the basis of constructing a framework of border geographic research integrating multi-subjects, multi-elements, and multi-scales, we propose to strengthen the research on border risk and security, cross-border cooperation mechanism, "border effect" theory, and sustainable border development, which may provide a support for China's border security and modern governance.

In recent years, the frequent extreme weather and climate events have attracted wide attention. Their disastrous process often stems from the interaction of multiple factors, which brings many challenges to regional security and risk prevention. Starting from a bibliometric analysis, this article systematically reviewed the progress of research on compound extreme events by focusing on the conceptual features, classification, and driving factors of such events, and summarizing the main methods for the spatial-temporal dependance analysis and hazard assessment of compound events. The review found that: 1) The research on compound extreme events has developed rapidly in recent years, and the types of events studied have become increasingly rich and diverse. 2) The research system has been established and increasingly improved, with significant advance in the research on the conceptual characteristics, dependance, causative mechanism, and risk assessment. 3) The research techniques were constantly evolving. Statistical modeling for joint probability based on Copula has developed from two-dimensional to multidimensional, and from static to dynamic; the precision of numerical simulations represented by the coupled hydrological-hydrodynamic and ocean models has been continuously improved. But further in-depth studies are still needed, especially for some key and difficult problems, such as diagnosing and modeling the complex dependance structure of temporally and spatially compounding events, the synthetic effect of weather system, large-scale circulation and human activity impact on the formation of compound events, hazard scenarios and multidimensional joint probability analysis of compound events, and so on. In addition, it is urgent to explore the non-stationary changes of the marginal distribution and dependance structure of compound events under climate change and their impact on the risk of compound events in the future.

Regional economic integration has become a necessary path to promote regional high-quality development in China, but relevant studies from the perspective of private enterprise investment are rare. Using statistical analysis and social network analysis methods, we analyzed the process of regional economic integration through the evolution of private enterprise investment network in the Lanzhou-Xining (Lan-Xi) urban agglomeration from 2013 to 2021, and explored the mechanism of change. The study showed that: 1) The Lan-Xi urban agglomeration was in the middle and late stage of industrialization, but the private enterprise investment network still showed an obvious inter-provincial "dual-core separation" structure, with a relatively high level of integration in Qinghai Province, and there were large differences in the inter-provincial investment behavior of different industries within the urban agglomeration. 2) The formation of the dual-core separation structure of the private enterprise investment network was mainly influenced by the current development stage of the region, and the provincial capital cities played a dominant role in this polarization, leading to extremely weak inter-provincial investment ties. 3) The administrative region economy and institutional thickness exerted a deterrent effect on the inter-provincial investment of private enterprises through external environment and internal decision making, respectively. Based on the above conclusions, starting from the low level of regional economic integration in the Lan-Xi Urban Agglomeration, this paper puts forward relevant policy recommendations to promote the formation of inter-provincial complementary regional economic layout with the goal of high-quality development.

In the new era, research on China's population aggregation and decentralization in different types of regions is of great reference value for the implementation of strategies for the new-type urbanization and rural revitalization. Therefore, we studied the spatiotemporal variations of population in China and its different types of regions (for example, urban agglomerations, original contiguous destitute areas, and border areas) at the county level based on the data of three censuses from 2000 to 2020. The results show that: 1) The pattern of China's population distribution, which is dense in the east and sparse in the west, had not fundamentally changed, and the population ratio of the southeast side to the northwest side of the Hu line is still 94∶6. Furthermore, the Chinese population had entered a period of negative growth, and more than half of the counties had negative population growth from 2010 to 2020. 2) The urban agglomeration areas were the main areas carrying China's population, accounting for nearly 90% of China's total population in 2020. From 2010 to 2020, among the 19 urban agglomerations of China, the Pearl River Delta and the Yangtze River Delta had the most significant population growth, while the Harbin-Changchun and central-southern Liaoning urban agglomerations experienced negative population growth. 3) The population of original contiguous destitute areas dropped continuously from 2000 to 2020, and the total population decreased by more than 11 million during the 20 years. But the population growth of three prefectures of southern Xinjiang and the Tibet area inhabited by ethnic minorities exceeded 15% from 2010 to 2020. 4) The population of border areas had been basically stable, but the population agglomeration index and population density decreased slightly from 2000 to 2020. In particular, the population of the northeastern and northern border areas declined significantly, both with a decrease of 15% from 2010 to 2020. The implications of this study are that the government should attach greater importance to the actual status of population change for carrying out targeted policies—such as the new-type of urbanization, rural revitalization, and national defense and security—under the new situation.

E-commerce specialized village is a new mode of transformation and upgrading of rural industry in the era of digital economy. Based on the spatial data of Taobao villages in China from 2015 to 2020, the spatial pattern and change of e-commerce specialized villages were explored by using GIS spatial analysis and geographical detector methods, and the mechanism of impact of different influencing factors was revealed. The results show that: 1) The overall spatial distribution pattern of Taobao villages was highly consistent with the basic geographic pattern of China, and the spatial and temporal change of Taobao villages was characterized by gradual spreading from the center to the periphery. 2) Taobao villages presented significant spatial agglomeration characteristics, with the intensity of spatial agglomeration increasing and range of high-intensity agglomeration expanding year by year. High-intensity Taobao village agglomeration areas appear in the traditional agricultural areas of the North China Plain. 3) The spatial clustering distribution of Taobao villages was relatively stable, and the high-high clusters were concentrated in southern Jiangsu Province, Zhejiang Province, Quanzhou and Putian in Fujian Province, and the Yangtz River Delta urban agglomerations. 4) Various influencing factors on the Taobao village spatial pattern change has different explanatory power—industrial foundation and geographic conditions were high impact factors, the influence of government behavior was steadily rising, social and economic influences showed an U-shaped trend of change, and the impact of the added value of the primary industry and the influence degree of the rural residential population in the third level factors were on the decline. The research results have important theoretical significance and practical value for deepening the theory of rural development, promoting the development of e-commerce specialized villages, and facilitating rural revitalization.

Based on the panel data of 238 countries and regions, this study examined the change of the spatial pattern of the global grain trade network at different scales from 1988 to 2018. The zero-inflated negative binomial was introduced to construct the gravity model for analyzing the driving factors of the global grain trade network. The results show that: 1) The scale of the global grain trade showed a rapid fluctuating rising trend, while the growth rate of trade fluctuated greatly between years. The structure of trade commodities was constantly diversified but is still dominated by wheat, corn, and barley. 2) The density of the global grain trade network is increasing, with polarization of some core nodes and increasing diversification of the overall trade network. For example, the position of North America, Western Europe, East Asia, and so on, in the grain trade network is relatively declining, while the position of Eastern Europe, South America, and so on, has increased. On the national scale, the interaction of grain trade among countries and regions has enhanced, as the structure of the grain trade network has changed from an "east-west axis" to "multi-point radiation" with a gradual shift from polarization to pluralism. Although the number of core nodes in the grain export network is increasing, regional grain export networks are still dominated by only several key countries and show a strong local polarization phenomenon, while the centralized characteristics of import networks are gradually weakened and more balanced. 3) Natural endowment of land resources, the structure of agriculture, and the degree of opening up to the outside world are the core driving factors for countries and regions to participate in the global grain trade network. The levels of price differences, language proximity, spatial distance, and societal governance also have a certain impact on the participation of countries and regions in the global grain trade network. The influence of other factors is relatively small.

Urban transportation resilience reflects the ability of the transportation system to maintain its basic functions and structure through its resistance, mitigation, and absorption under extreme conditions, or the ability to restore the original equilibrium or reach a new equilibrium state within a reasonable time and with reasonable cost. Global warming, sea-level rise, and rapid urbanization all increase the risk of compound extreme weather events, presenting challenges for the operation of urban-related infrastructure including transportation infrastructure. In this context, some questions become important. For example, how to measure the strength of urban transportation resilience under extreme weather events (including the impact of different extreme weather event intensities on its strength); how to monitor its spatial and temporal features and evolution trends; and how long will it take for the entire system to restore balance? At present, effective monitoring methods for transportation resilience under the influence of extreme events are lacking, especially the monitoring of the temporal and spatial dynamic changes of transportation resilience under climate change, to answer these questions. Therefore, it is urgently needed to solve the problem of accurately identifying the state of urban transportation resilience under extreme weather events and improving the level of prevention and control of transportation system impact of natural hazard-related disasters. The development of big data mining technology and deep learning methods for spatiotemporal prediction made the construction of spatiotemporal datasets for evaluating and predicting urban transportation resilience possible. Such datasets can reveal the spatiotemporal evolution features, changing trends of urban transportation resilience intensity under the influence of extreme weather events, as well as the mechanism of influence. It indicates the key research areas that should be focused on for transportation resilience under climate warming. This article reviewed and summarized the research on transportation resilience in China and internationally in the past 50 years, analyzed the deficiencies in the existing research based on the relevant research results of transportation resilience in China and globally, and identified the key areas and directions of the research on transportation resilience under climate warming in order to provide new ideas for future research on transportation resilience.

Urban-rural integration (URI) is a new idea to guide the urban-rural transformation in China, and exploring the spatio-temporal characteristics and driving mechanism of URI in China is an urgent need to overcome the dilemmas of insufficient rural development and unbalanced urban and rural development. Based on the process framework of "foundation-motivation-result" of URI, an evaluation indicator system was constructed. The improved entropy evaluation model and the kernel density estimation method were used to quantitatively measure the spatiotemporal evolution characteristics of URI level of 31 provinces, autonomous regions, and municipalities in China's mainland from 2000 to 2020. This study further used the Geodetector to explore the heterogeneous evolution of driving factors for URI level in different regions of China. The main conclusions are as follows: 1) From 2000 to 2020, the URI level in China decreased first and then increased, showing a √-shaped trend, and its spatial differences narrowed. 2) The URI level in China presented a spatial pattern of high in the east and low in the west, divided by the Hu Huanyong Line. The high-value centers showed prominent polarization characteristics and presented a zonal aggregation trend. The medium-value areas were clustered but weakened，and showed a spreading trend from the eastern to the central and western parts. 3) At the national scale, the core influencing factors of URI level were population mobility, economic development level, urban-rural income gap, and educational supports, potential factors were the optimization of industrial structure and the opening-up level, and threshold effect existed in investment benefit and government intervention. At the regional scale, the core driving forces of URI level in China showed obvious spatial heterogeneity, and in 2020 they were economic development level, investment benefit, and government intervention in the eastern region, investment benefit, opening-up level, and urban-rural income gap in the central region, are educational supports, government intervention, and the optimization of industrial structure in the western region. The interaction of driving factors had far more influence on URI level in China than individual factors, and the interaction between traffic accessibility and other socioeconomic factors had been significantly enhanced. Research on the spatio-temporal evolution and mechanism of URI in China can provide theoretical basis for rural revitalization and high-quality urban and rural development.

The spatiotemporal characteristics of Meiyu intensity index and different precipitation levels during the Meiyu period over the Yangtze-Huai River Basin are still unclear during recent 60 years under global climate change. This study used observed daily precipitation and temperature data from 239 meteorological stations over the Yangtze-Huai River basin from 1961 to 2020 combined with NCEP/NCAR reanalysis data to identify the Meiyu process and investigate the spatiotemporal characteristics of Meiyu intensity index, the number of rainy days, precipitation amount, precipitation incidence rate, and precipitation contribution rate of different precipitation levels during the Meiyu period, and calculate the contribution rate of urbanization to heavy precipitation indices during the Meiyu period. It aimed to provide references for early warning of rainstorm and flood events, flood and drought disaster prevention, and water resources regulation in the Yangtze-Huai River Basin during the Meiyu Period. The research results show that: The average Meiyu onset date and ending date were the earliest in area I (Jiangnan area), followed by area II (middle and lower reaches of the Yangtze River) and area III (Jianghuai area), and the length of the Meiyu period was 30 days, 30 days, and 24 days respectively. There was no obvious trend for onset date, ending date, and length of the Meiyu period. The average Meiyu rain intensity in area I was the highest, at 367.6 mm, followed by area II at 298.4 mm and area III at 253.5 mm; the Meiyu rain intensity index in area II showed a significant increasing trend in recent 60 years, and the average Meiyu intensity index was the highest in area Ⅱ. Violent Meiyu are most likely to occur in area II, and the inter-annual variation of the Meiyu intensity index was the largest in area III. Meiyu precipitation amount in the central part of areas Ⅰ and Ⅱ was relatively high, with the highest number of rainy days in area Ⅰ, followed by area Ⅱ and the lowest was found in area Ⅲ. During the Meiyu period, the number of light rain days was the largest and the incidence of precipitation was the highest, while the corresponding indices of moderate rain, heavy rain, and rainstorm decreased in turn. The trend of light rain days and moderate rain days was not obvious for most stations, but the number of heavy rain days and rainstorm days in the central and eastern parts of area II increased significantly. The trend of the incidence of heavy rain and rainstorm was not obvious for most stations, but the incidence of light rain and moderate rain for many sites in area II decreased significantly, which is the reason for the significant decrease of the incidence of precipitation during the Meiyu period in eastern area Ⅱ. Rainstorm amount accounted for the largest proportion of precipitation during the Meiyu period, the contribution rate of rainstorm was also the largest, and heavy rain, moderate rain, and light rain decreased in turn. The significant increasing trend of heavy rain and rainstorm precipitation at the eastern stations in areas I and II is the reason for the significant increasing trend of Meiyu precipitation in this area. The trend of precipitation contribution rates of different magnitudes of precipitation was not obvious for most stations, and only 17 stations in the central and eastern parts of area II showed a significant decreasing trend of the contribution rates of light rain and moderate rain. Urbanization aggravates the increasing trend of heavy precipitation, and the contribution rate of urbanization to R95P and R99P was 10.59% and 17.39%, respectively.

With the advent of the post-industrial era, a "green turn" has gradually become the basic principle of global urban renewal. However, green initiatives and practices in urban renewal often focus on environmental sustainability, neglecting the green gentrification that can be triggered at the social level. In the context of urban renewal in China, urban greening practices have emerged with many representations similar to the phenomenon of green gentrification, but this has not attracted the attention of scholars in China. This study adopted a qualitative research method to investigate the effects and mechanisms of green gentrification in the context of urban renewal, taking the greening practices of urban agricultural parks as an example. The study found that: 1) In the context of urban renewal, urban greening practices imply a logic of gentrification in action, and the postmodern aesthetic and experiential landscape it creates becomes a place representation of green gentrification. 2) Greening practices oriented to serve the urban elite have triggered landscape segregation and stratification, but under the guarantee of the Chinese land tenure and management system, the indigenous people are not displaced but receive dividends from the recapitalization of the land. 3) The government, village collectives and residents, and developers have formed green growth alliances to meet their political and economic demands for the purposes of urban governance, land rents, and economic interests, respectively, eventually forming a government-led green gentrification operation mechanism. This study empirically analyzed green gentrification, which originated in western societies, in the institutional and social contexts of China, expanding the connotation and explanatory validity of green gentrification in the context of multiple geographies, and providing new theoretical perspectives and practical insights for understanding the change of human-land relationship in the context of urban renewal in China.

Maps are the basic language of geography and an indispensable tool for spatial analysis. But maps have long been seen as an objective, neutral scientific product. Inspired by critical geography, critical cartography/GIS emerged with the goal of elucidating the nature of discourse, power relations, and even the physical environment embedded in cartographic practice and challenging the untested but taken for granted assumptions in cartographic representation. After nearly 40 years of debates, this field of research has been gradually defined, and a blueprint of "hybrid geographies" has gradually emerged. Through the combination of various geographical methodologies, critical cartography/GIS has generally formed two research directions. The deconstruction approaches mainly start from the identity of cartographers and the production process of map knowledge, and analyze the inseparable relationship between "cartographicality" and national governance as well as the inherent mechanism of power. The construction approaches mainly explore the new production and representation of maps by means of collaborative mapping and counter-mapping. The research of critical cartography/GIS in China has just started, so it is necessary to continue to draw on the achievements of critical geography to carry out the deconstruction research of different types of maps in different historical periods, strengthen the convergence of construction path and deconstruction path, and actively participate in the social applications of research results.

The securities of water, energy, and food are three sustainable development goals (SDGs) and have close interactions with other SDGs. Based on the recent studies of the theory, methodology, and application of the water-energy-food nexus (WEF nexus) system, this study analyzed the WEF nexus system in terms of its definition and composition, internal interaction processes, inputs and outputs, and influencing factors. In the process of analysis, the characteristics of the spatial and temporal scales of the research object were taken into account, and the inputs and outputs of the WEF nexus system were clarified from the perspective of the material, energy, and information flows. This study also illustrates the positive and negative impacts of climate change on the water, energy, and food subsystems and their interactions, as well as the impacts of human activities on the WEF nexus system. Furthermore, a research framework of the WEF nexus system covering research themes-disciplinary theories-technical methods-practical applications was proposed, according to the interactions of the WEF nexus system and other SDGs. The introduced framework illustrates three research topics: 1) Linkages within the WEF nexus system and the overall state. 2) The drivers of system change. 3) The influences of the system on socioeconomic development, ecological and environmental protection, and so on. At last, this study highlights the urgent need for interdisciplinary analysis of WEF nexus systems due to the insufficient research and application of nexus relationships and the diversity of spatial and temporal boundaries. The research perspectives based on comprehensive analysis indicators and calculation methods of nexus relationships are presented, and the necessity and ways of coupled application of multi-scale research results is introduced. This study provides a new insight into the research on the basic theory and application of the WEF nexus system, as well as some guidance on the analytical ideas and methods of global and regional sustainable development goals.

A rare persistent high temperature event occurred in the Yangtze River Basin in summer 2022, which caused serious impacts on the life and production of the provinces in the basin. Scientific analysis of the causes of this high temperature process is of great significance for improving the prediction and early warning of high temperature processes. Based on the NCEP/NCAR reanalysis data and the daily temperature data collected from 699 stations in the Yangtze River Basin, this study examined the atmospheric circulation characteristics and the causes of this high temperature process. The findings indicate that: 1) The high temperature process that occurred in the Yangtze River Basin in 2022 ranked the highest in terms of the area of influence, intensity, duration, and comprehensive strength since 1961. 2) There were mainly two circulation causes that attributed to this high temperature process. The first was the impact of local circulation, that is, the middle and upper layers of the troposphere over the Yangtze River Basin was controlled by the abnormal anticyclonic circulation generated by the equivalent barotropic mechanism. The second was the impact of large-scale circulation, that is, the South Asia High and Western Pacific Subtropical High moved in an opposite direction and overlapped over the Yangtze River Basin. Under the control of high pressure, the sinking movement over the Yangtze River Basin and the solar radiation reaching the ground are obviously strong, which led to strong extreme high temperature. 3) The main reason for the long duration of the abnormal circulation is that with the Rossby wave transmitting energy eastward from Western Europe and the Lake Baikal, the circulation distribution presented a "two grooves and one ridge" model from west to east in the middle and high latitude of Eurasia and a stable "three-wave" model in the middle and high latitudes in the northern hemisphere. Therefore, the energy converged in the subtropical region above the Yangtze River Basin, which helped maintain the intensity of the subtropical high and the occurrence of the abnormal positive height anomalies over the Yangtze River Basin.

Through extensive and detailed field investigation inside and outside the Zoige Basin in eastern Tibet Plateau, a typical sedimentary profile containing the stratigraphic sequence of paleolake facies and paleo-riverbed floodplain facies was found in the front of the second terrace of the Yellow River in the Maqu section at the outlet of the Zoige Basin. Through grain size characteristic analysis and Optically Stimulated Luminescence(OSL) dating, we found that: 1) The pale-blue-grey paleolake sedimentary layer in the profile indicates that the lacustrine sediment formed in the deep-water anoxic environment, while the mottled pebble layer covered by the pale-yellow-orange lenticular sand layer was a typical fluvial floodplain sediment, which indicates the process of strong dynamic flow. The unconformable contact relationship between the two layers indicates that the profile is a typical sedimentary evidence for studying the Zoige Basin dissected by the Yellow River. 2) The OSL dating results of the top boundary of the pale-blue-gray paleolake sedimentary layer and the bottom boundary of the paleoshore-shallow lake sedimentary layer show that the Yellow River dissected the Zoige Basin at 37 ka BP, resulting in the leakage of lake water. At 35 ka BP, the lake water became shallow and disappeared, and then the Yellow River connected the water system of the Zoige Basin. 3) The strong neotectonic movement of the East Kunlun fault in late Pleistocene and the warm and humid climate of the Tibet Plateau in 37 ka resulted in the aggravation of the headward erosion of the paleo-Yellow River source in the rift valley grassland, and the Zoige Basin was dissected by the paleo-Yellow River from the west to the east in the Maqu bottleneck reach, resulting in the discharge of the paleolake water through the Yellow River, thus connecting the water system of the Zoige Basin and making it the source of the Yellow River. The study results have important scientific significance for an in-depth understanding of the evolution of river-lake water system and the formation of Yellow River water system in northeastern Tibet Plateau.

The transformation and development of urban waterfront space is the key way to promote the optimization of urban space and the adjustment of industrial structure, which has become the main part of the current international urban renewal and redevelopment efforts, and a large number of relevant studies have emerged. Therefore, it is necessary to summarize the existing studies. Taking the relevant publications in the Web of Science and Science Direct databases from 1988 to 2020 as the analysis object, this study systematically examined the research results of the transformation and development of urban waterfront space abroad, summarized and analyzed the research contents and main conclusions from the aspects of the transformation process, mode, motivation and mechanism, and effect. The results show that international studies on the transformation and development of waterfront space mostly used qualitative methods to carry out descriptive analysis of cases, the research themes have shifted from paying attention to practical needs to exploring underlying academic issues and gradually diversified, and the research perspective increasingly emphasizes humanism and the concept of equality. Finally, considering the international research experience and domestic reality, this study proposed that in the future, China should change the research perspective and research object, pay attention to the comparative study of multiple cases in different regions, reveal the transformation process of urban waterfront space, simulate the transformation mechanism of urban waterfront space, and comprehensively evaluate the transformation effect of urban waterfront space, so as to optimize and improve the research system of urban waterfront space in China.

Constructing a vibrant urban space by optimizing urban built environment is a significant measure to shape and develop urban vitality. However, the nonlinear and threshold effects of variables on urban dynamics are often overlooked in most existing studies. In this study, we used the Wuhan metropolitan area at the weekend as a case to quantify the spatiotemporal pattern of urban vitality with population heat data in 2019. We investigated the nonlinear influence of urban built environment on urban vitality and extracted the optimal thresholds for key variables with the gradient boosting decision tree-Shapley additive explanations (GBDT-SHAP) model. The results indicate that: 1) The distribution of urban vitality showed distinct spatiotemporal and functional heterogeneity in the Wuhan metropolitan area. Spatially, urban vitality showed an overall characteristic of high in the center and low at the periphery; temporally, it gradually increased from 7:00 a.m. and peaked in the afternoon and evening; functionally, urban vitality was higher in areas with better infrastructure facilities and near large shopping centers, and lower in industrial areas. 2) The built environment in the Wuhan metropolitan area significantly affected the intensity of urban vitality, and its nonlinear influences and threshold effects were significant: the impact threshold for large shopping centers was roughly 3000-4000 m; the impact of subway on urban vitality was mainly in the intra-city area and the subway stations served the areas within 1500 m; the point of interest (POI) mix above 0.4 inhibited urban vitality. The SHAP values compensated for the shortcomings of traditional multivariate linear models in terms of interpretability. 3) The three variables of distance to central business district (CBD), distance to subway stations, and sky openness and business type have time-varied effects, and the importance of their impacts on urban vitality changes over time. Implementing the transit-oriented development (TOD) concept and improving the connection of metro traffic with large shopping areas are effective measures to enhance the vitality of the city. Setting up outdoor open space promotes residents’ morning exercise and social activities. Adding small dining and recreational spaces is also a measure to enhance vitality. These nonlinear effects and thresholds help planners make better decisions.

The 2008 global financial crisis had a huge impact on China's real economy, and inspecting the imbalance and differentiation mechanism of the regional economic recovery process after the crisis is conducive to providing a reference for promoting regional high-quality and sustainable development. Based on the multidimensional resilience measurement framework, this study comprehensively investigated the dynamic evolution process of economic resilience in the Yangtze River Economic Belt after the 2008 global financial crisis, and focused on the temporal variation characteristics and spatial differentiation patterns of resistance and resilience. On this basis, the fixed effect panel regression model was used to analyze the role of factors such as industrial development status, regional development foundation, level of opening up, government management level, and innovation environment on economic resilience. The study found that at the overall level, the resistance of the Yangtze River Economic Belt after the impact showed a trend of first rising and then declining and the overall performance was high, but the resilience showed a trend of decline-rise-decline and the overall performance was low. The fluctuations in export resistance and resilience were much greater than the fluctuations in the dimensions of GDP, industry, consumption, and employment. Regression models showed that diversity and related diversity and regional innovation capabilities, although limited in the process of resisting risks in the early stage of the crisis, were conducive to the rapid regional resumption of growth after the crisis, areas with strong government management capabilities may hinder economic recovery to a certain extent, and the ability to open up to the outside world has no significant impact on resistance and resilience.

Multi-hazard risk assessment is the basis for formulating integrated risk governance strategies. Through examining the risk assessment practices in China and internationally, this study selected five authoritative global risk assessment reports, including the Global Assessment Report on Disaster Risk Reduction, Global Climate Risk Index, The Index for Risk Management Report, World Risk Report, and World Atlas of Natural Disaster Risk, to compare their objectives, contents, models, and results of assessment. The main conclusions are as follows: 1) The five risk assessment reports have different focuses in terms of objectives, and four of them regularly publish new reports to analyze the dynamic process of change that facilitates the identification of risks through continuous risk assessment. 2) The methods characterized by the synthesis of risk elements is easy to apply, but it is necessary to further improve the applicability of indicators and adopt more intuitive and practical risk representation methods. 3) The Belt and Road initiative countries have slightly higher risk levels than the global average. In the future, we need to deepen the research on the integrated risk assessment method of multi-hazards, strengthen the practice of natural disaster risk assessment in China, and explore the disaster risk management system of regional linkages. 4) On the whole, the five risk assessment reports all have their own advantages and disadvantages. In the future, we can combine the concepts of "multi-hazard additive losses" and "disaster chain losses" to enrich the models and methods, indicator system, and result representation of integrated risk assessment.

Educational tourism is one of the new tourism models in China. For traditional ancient villages, the development of educational tourism is of great significance to innovate and enrich the tourism model, promote the transformation and upgrading of tourism products, and build a people-oriented educational tourism supply system. Taking Xidi and Hongcun—typical ancient villages in southern Anhui Province and World Heritage Sites and national 5A scenic spots—as the study sites and educational tourism tourists (mainly primary and middle school students) as respondents, and based on 547 samples of questionnaire data, this study constructed a structural equation model of the influencing factors of educational tourism tourist satisfaction from the perspective of tourist experience, and conducted a cross-sample stability test of the model. The results show that: 1) The factors that influence the tourist satisfaction on study travel to traditional ancient villages include cultural cognition, emotional experience, aesthetic experience, and learning cognition. Among these factors, tourists have the deepest perception of learning cognition (4.026), followed by aesthetic experience (4.033), cultural cognition (3.884), and emotional experience (3.801). 2) The results of the structural equation model show that cultural cognition, emotional experience, aesthetic experience, and learning cognition of educational tourism tourists in Xidi and Hongcun all have a significant positive impact on the satisfaction of these tourists. In terms of the magnitude of path coefficient, cultural cognition is the primary factor affecting the satisfaction of educational tourism tourists, with a path coefficient of 0.510; emotional experience is the second most influential factor, with a path coefficient of 0.340; aesthetic experience and learning cognition rank third and fourth, with path coefficients of 0.224 and 0.212 respectively. 3) The model has good cross-sample stability. Three nested models were obtained by gradually adding parameter constraints to the benchmark model, and the results show that the chi-square increment and fitting index are generally good, which further supports the research hypothesis. The research results can provide decision-making reference for the scientific development of educational tourism products in Xidi and Hongcun and the high-quality development of educational tourism industry in traditional ancient villages.

One of the basic topics in population geography is how the population distributes and changes on terrain gradients. With the improvement of data accuracy and quality, it is feasible to conduct macroscopic analysis for this question based on kilometer grid cells. This study analyzed the distribution and change characteristics of China's population on the gradients of elevation, ruggedness, and slope from 2000 to 2020, using methods of frequency distribution statistics, based on 1-km grid statistical cells, and using spatial demographic datasets (WorldPop) and digital elevation model datasets (SRTMGL1). The effects of different digital elevation model datasets (including ASTER GDEM and SRTMGL1) and spatial demographic datasets (including WorldPop, LandScan, and GPW) on the results were also compared and the differences between the 1-km grid and 100-meter grid data were further explored with SRTMGL1 and WorldPop. The results show that: 1) The population increasingly tends to be distributed at the lower position of terrain gradients. The half-balance points of the population distribution on elevation, ruggedness, and slope gradients were 95.6 m, 50.7 m, and 3.01° respectively in 2000, and decreased to 77.0 m, 46.8 m, and 2.88° in 2020. 2) Dominant area of population distribution relative to land area has been stably located at a lower position of terrain gradients. The upper boundary of the dominant part of the population over terrain (MU) is stably located at the elevation of 520 m, the ruggedness of 137 m, and the slope of 6.84°, respectively, and the population dominance rate rose from 0.511, 0.248, and 0.217 in 2000 to 0.522, 0.274, and 0.255 in 2020, respectively. 3) Different spatial demographic datasets have no effect on the distribution and change pattern of population on terrain gradients, while DEM datasets have significant effects on the ruggedness gradient and slope gradient distribution of population. There is no difference between 1-km grid and 100-meter grid data for this study, and the 1-km grid dataset is recommended for the study of population distribution at the national scale and above. This study provides a new basic reference for understanding of the relationship between population distribution and terrain in China at the kilometer grid scale.

Transportation is the physical carrier of knowledge and technology spatial flows such as talent and capital flows in innovation networks, and its impacts on urban innovation capacity have become a cross-cutting frontier in economic geography. Based on the city-scale data of China from 2007 to 2018 and taking air and high-speed rail transportation as examples, this study constructed a theoretical framework for the effect of transportation on urban innovation capacity, adopted the two-way fixed-effects panel regression model to empirically test the multiple heterogeneity mechanisms of aviation and high-speed rail on urban innovation capacity, and explored the mediation effects of knowledge dissemination, capital accumulation, and industrial upgrading between transportation and innovation capacity. The results are as follows: 1) Both aviation and high-speed rail development have significant positive impacts on urban innovation capacity, and the spillover effect of high-speed rail on urban innovation is about three times that of aviation. 2) The innovation spillover effects of aviation and high-speed rail on different types of cities are significantly different. In terms of urban grade heterogeneity, the positive impact of aviation and high-speed rail on the innovation capacity of central cities is higher than that of other cities. In terms of population size heterogeneity, aviation has a significant positive impact on the innovation capacity of large and medium-sized cities and an inhibitory effect on small cities, while high-speed rail transportation has a positive impact on urban innovation capacity of cities of different population sizes, showing the trend of large cities > medium-sized cities > small cities. In terms of regional heterogeneity, aviation and high-speed rail have improved the innovation capacity of the eastern, central, western, and northeastern cities of China in varying degrees with a significant Matthew effect, and eastern China has a prominent dominant position. 3) Both aviation and high-speed rail can indirectly promote urban innovation capacity by stimulating technology transfer, venture capital allocation, and foreign capital allocation. Aviation can also indirectly promote urban innovation capacity by stimulating industrial upgrading.

With the acceleration of population aging in China, the scale of the elderly migration is gradually increasing. Elderly migration might exert a significant impact on personal well-being, regional age structure, and the development of the society and economy. However, academic and policy studies focusing on this phenomenon are few. This article reviewed the relevant literature from three aspects of elderly migration: spatial pattern, the decision-making mechanism, and impact. The study revealed that: 1) In terms of spatial pattern, four main types are identified—long-distance migration to small cities, long-distance migration to big cities, short-distance migration to the suburban areas, and short-distance migration to central urban districts. Different countries show different characteristics. 2) In terms of the decision-making mechanism, elderly migration is driven by the needs of economic support, health care, comfort, and sense of belonging, while personal physiological, economic, and social factors affect the ability to migrate. 3) In terms of impact, elderly migration exerts influence on individual physical and mental health, social integration, regional economic and social development. Future study needs to consolidate abundant research data and methods, construct an effective theoretical framework, thus provide a scientific basis for the implementation of population aging strategy and the construction of an age-friendly city.