Yangtze River Delta, as a pivotal region where the coastal axis and the riverside axis intersect, is characterized by complexity, diversity and typicality of the spatial structural evolution. Therefore, understanding its evolutionary pattern and constructing a theoretical model has important theoretical significance and application value. According to the core-periphery structure theory, the Yangtze River Delta can be divided into a core area that is centered on the Taihu Lake Basin and remaining periphery areas. However, due to its location at the junction of the river and the sea, a gateway area has emerged within the periphery area, thus forming a spatial structure that is composed of the core area and the gateway area. In the early period, the core area was centered on Suzhou, and a five-tier central place structure became well established since ancient times. However, the gateway area kept evolving and underwent three main changes: in ancient times, the gateway area was centered on Yangzhou, forming the canal gateway cluster; in the modern age, the gateway area became centered on Shanghai, forming an offshore gateway cluster; and in the contemporary era, the gateway area became centered on Ningbo, forming an oceanic gateway cluster. Their corresponding navigation capacities were 500 t, 10,000 t, and 200,000 t, respectively. Therefore, in addition to the existing central place theory and seaport spatial structure theory, the spatial structure evolution of the Yangtze River Delta presents a new evolutionary model: namely, the fusion evolutionary model of central places and port gateways. According to this model, in the early period, it was an endogenous evolution of the core area's spatial structure, which was in line with Christaller's hexagonal structure; while in modern times, the evolution of the spatial structure of the Yangtze River Delta was no longer dominated by central places, but rather, it became dominated by the gateway areas, making the k = 3 market principle turn into the k = 4 transportation principle. In this way, the Yangtze River Delta provides a globally exemplary empirical case for validating the process test of the central place theory, analyzing functional attributes of urban centrality and gateway, and refining the relevant theoretical model.

Geographic environment has exerted profound effect on the origin and evolution of world civilizations. Chinese civilization budded and evolved on a vast and varied territory between Yellow and Yangtze rivers, and has been thus deeply affected by the local geographic conditions. But it has been hardly seen to explore the origin of Chinese civilization from the perspective of geography. On the basis of integrated scientific investigation in China's north-south transitional zone, geographic analysis of Neolithic culture distribution and interpretation of pre-Qin and Qin-Han ancient literature, the conclusions can be drawn as follows: (1) The early agriculture pattern of "Rice in the south and millet in the north" and the ancient astronomy formed before about 8000 years were the background for Chinese civilization. The geographic distribution of Neolithic Dadiwan, Yangshao, Majiayao and Longshan culture sites showed that the earliest civilization elements appeared in the upper reaches of West-Hanshui and Weihe rivers, with a spatial trend of spreading toward east. (2) The West Qinling Mts. region, located between the Tibetan Plateau and the Jialing River, especially its inner Chenghui and Xili basins, being characterized by superior natural conditions and resources, is closely related to the three major mysteries concerning the origin of Chinese civilization, i.e., the main areas of the ancient Di and Qiang ethnic groups, the location of ancient Kunlun Mts., and the site of Dayu water control. (3) The Qin ethnic group stepped onto the stage of history by assisting Dayu in water control, and in their history of multiple ups and downs, built the grand water control projects in ancient China, such as the Dujiangyan Irrigation Project, Zhengguo Canal, Lingqu Canal, etc., and pioneered the time of "Books with the same text" and "County system", forming the main line of the origin and early evolution of Chinese civilization. (4) The West Qinling areas are still basically a "blind zone" in archaeological and historical research. It is highly recommended to conduct systematic and in-depth archaeological and historical research in this region so as to realize the breakthrough in the exploration of the origin of Chinese civilization as soon as possible.

New quality productive forces are advanced productivity that is freed from traditional economic growth mode and productivity development paths, features high-tech, high efficiency and high quality driven by technological innovation in the new era. From the geographical perspective, developing new quality productive forces is the ability to coordinate new human-earth relationships in the Anthropocene, where human activities dominate, promote the harmonious coexistence of humans and nature, transform green waters and mountains into gold and silver mines, drive high-quality development and layout, and comprehensively implement the construction of a beautiful China. Geography focuses on studying the emergence and development process, formation and evolution characteristics, spatial organization patterns, and regional differentiation laws of new quality productive forces driven by innovation, so as to promote the human-earth system to enter the ecological civilization stage of highly coupled and harmonious coexistence between humans and nature. Compared with traditional industries, the evolution of new quality productive forces has experienced a fluctuating process of evolution from low-quality productivity to medium-quality, medium-high-quality, and then to high-quality productivity, accompanying the emergence of continuous technological revolutions and industrial revolutions. They exhibit basic characteristics such as high coupling, deep integration, super correlation, rapid iteration, and spatial differentiation. The pivotal directions propelled by the drive of new quality productive forces for geographical research encompass the following: re-coordinating human-earth relationships to foster novel harmonious coexistence conducive to the realization of a beautiful China; restructuring industrial systems to align with the new quality productive forces, facilitating profound industrial transformation; reallocating geographical elements to establish a novel mechanism that harmonizes natural, humanistic, and data-driven components; reshaping spatial pattern to engender a fresh spatial paradigm wherein new quality productive forces and traditional industries are integrated deeply; rebuilding ecological environment to leverage them as green engines of productivity, thus enhancing the intrinsic value of ecological capital; revitalizing geographical science through the refinement and updating of theories and methods, thereby constructing a modern disciplinary landscape of geography.

The statistical definition of migration in China is attached with its unique household registration (hukou) system, the migrants so defined are also called the floating population. A new analytical paradigm is needed to deal with the complexity of sub-flows in the floating population. The paper classifies five types of the floating population in census context by referring the UN migration criteria, and constructs a new paradigm for analyzing the floating population in China. As a particular provincial-level region (hereafter province) is concerned, the inflow and outflow people belong to different hukou groups balanced by their own counter-flow, namely, inflow vs back-inflow (both have no hukou of the province), outflow vs back-outflow (both have hukou of the province). With the clue of inter-census migration cohort, a sub-flows model is constructed to identify the inter-provincial migration based on the retention rate. The annual retention rate of the inter-provincial migration cohort from 2010 to 2020 is 88.7%. Based on the provincial retention rates, an all-increment table of population change by province in China is made by modelling simulation. The paper surfaces new characteristics of population growth and inter-provincial migration: (1) Provincial population changes are divided into five types, among which the inflow-leading increase type is mainly found in municipalities and the eastern coastal areas, while the fertility-leading increase type and the fertility-overriding increase type are mainly in the western provinces and the agricultural provinces in the middle, and the outflow-overriding decrease type and the outflow-leading decrease type in Shanxi, Inner Mongolia, Gansu and the northeastern provinces. (2) The mechanical growth of population can be divided into four types: rapid increase, equilibrium, outflow-overriding decrease and dual decrease (both hukou and non-hukou migration are negative). A "W"-shaped mechanical growth rate profile from northwest to southeast is found with the equilibrium belt standing in its middle. (3) Population floating is divided into three types. The counter-flows are highly-correlated: inflow rate and outflow rate are negatively correlated while the inflow-back-inflow and outflow-back-outflow are significant positively correlated. The analytical paradigm and model of floating population in China can be further extended to the study of "citizenship seeking migration" including international migration, and even further to identity migration including migrations with status changing such as enrollment, employment and marriage.

In the course of urbanization in mountainous and hilly regions, the rapid and disorderly expansion of urban areas has led to environmental degradation of natural landscapes, the gradual erosion of cultural heritage inherent to landscapes, and an intensification of the conflict between human activities and environmental preservation. This dilemma has emerged as a prominent challenge confronting the sustainable development of cities. The integrated advancement of mountain management, water governance, and urban planning emerges not only as a pragmatic imperative for new urbanization and the realization of a visually appealing China, but also as a pivotal pillar supporting urban spatial restructuring and the pursuit of green, low-carbon transformations. This study advocates for a comprehensive exploration of the reciprocal influences and interactions between urban spatial expansion and natural landscapes, necessitating the adoption of an integrated research pattern. This pattern systematically scrutinizes the organizational dynamics and mechanisms of interaction among urban physical spatial configurations, natural ecological networks, and the structure of landscaping and cultural spaces. The spatial pattern termed "mountain-water-city" encapsulates the symbiotic relationships forged through the interplay and adaptation between urban artificial environments and natural landscape environment, with an emphasis on the holistic fusion of urban spaces, natural elements, and cultural components. Building upon this conceptual foundation, the present paper endeavors to elucidate the theoretical contexts and practical imperatives underlying the investigation of the "mountain-water-city" spatial pattern. It delves into the conceptual nuances of this spatial pattern, elucidating its constituent elements, hierarchical scales, and formation mechanisms from a comprehensive perspective integrating spatial, natural, and cultural interactions. Subsequently, it examines the analytical framework and future prospects for research on the "mountain-water-city" spatial pattern, which should center on analyzing its spatiotemporal processes, identifying key controlling factors, and discerning its evolutionary patterns. Furthermore, it should elucidate the driving mechanisms, organizational models, and holistic impacts shaping the formation and evolution of the "mountain-water-city" spatial pattern, as well as explore governance strategies and regulatory pathways conducive to fostering the symbiotic development of this spatial pattern.

Shanghai is one of the most significantly urbanized cities in modern China, and its urban spatial pattern and urban area have changed dramatically since its opening up (1843-2020). Reconstructing and analyzing the expansion process of Shanghai has great importance toward attaining a deeper understanding of China's urbanization. This study collected multi-source and multi-precision urban spatial data such as old urban maps, topographic maps of the Republic of China (1912-1949), declassified images from the U.S. military (KeyHole), and remote sensing data (Landsat), and reconstructed a long time series of urban built-up areas, and finally examined the evolution process and driving forces of the spatial structure of Shanghai. The results show that: (1) Since 1843, the area of urban built-up areas increased tremendously, with a total expansion of about 1453 times, and the expansion rate and expansion intensity also changed drastically. (2) The overall change trend of compactness is decreasing, and the fractal dimension shows a certain cycle. (3) The center of gravity of the built-up area in different periods showed a trend of developing first to the north and then to the south, and the most important direction of expansion was southwest and west by south. (4) The urban change was complicated by multiple driving factors: the natural location established the prerequisite for the development of Shanghai as a port city; as the most fundamental driving force, social change and policy determined the main direction of urban development at different stages; the spatial agglomeration of industry and trade is the direct cause of the formation and expansion of cities; population migration also injected new impetus into the urbanization; transportation, as an urban infrastructure, has been used to strengthen the connection between the city's external and internal regions. This study clarifies the processes and mechanisms of urban expansion in Shanghai and provides historical knowledge and scientific support for a deeper understanding of urban change and the evolution of the human-land relationship. Moreover, the ways in which a set of general data with a wide coverage and high resolution can be used for the study of the spatial and temporal processes of urban expansion on a centennial scale are discussed, which is quite instructive for understanding the pre-remote sensing era and developing longer time series.

Deepening the understanding of thermal comfort conditions of urban and rural residents is important for improving the outdoor thermal environment. Based on ERA5-Land reanalysis data, this study quantifies the thermal comfort along the urban-rural gradient (urban core-urban expansion-rural area) in 101 large cities in China during the summers from 2000 to 2020 by taking physiological equivalent temperature (PET) as the evaluation index, and explores the spatiotemporal characteristics of thermal comfort and its drivers along different gradients using the Sen's slope estimation, Mann-Kendall significance test and geodetector model. The results show that: (1) The average PET in the core areas (29.89 ℃) of case cities is slightly higher than that in the expansion areas (29.86 ℃) and much higher than that in the rural areas (28.94 ℃), and the cities with higher PET in each gradient are mainly located in the Beijing-Tianjin-Hebei region and the middle reaches of the Yangtze River. (2) PET shows an increasing trend from 2000 to 2020, with an increasing rate of 0.24℃/10a in the core and expansion areas, and 0.22 ℃/10a in the rural areas. (3) Natural factors dominated by vegetation coverage and socioeconomic factors dominated by population density are key determinants of PET in the core and rural areas, respectively, while the drivers of PET in the expansion areas are unstable, with vegetation and impervious surface coverage playing an increasing role. As PET rises, the population exposed to uncomfortable environments increases, and this state of affairs poses new challenges for addressing thermal environmental issues. In the future, more studies on the thermal environment in urban and rural areas need to be conducted to provide a more comprehensive reference for the development of thermal adaptation strategies.

Geopolitics is increasingly a focus in ethnography and social networks research, with an urgent need for China to address international criticism regarding the persistent conflicts of ethnic armed organizations (EAOs) in northern Myanmar. These critiques suggest that EAOs maintain "killed but not extinguished" and conflict persistence, drawing sustenance from a complex cross-border network with China, gaining essential resources like food and shelter. Employing long-term ethnographic tracking and social network analysis, this study examines the intricate relationship between the China-Myanmar cross-border complex social networks and the conflict in northern Myanmar. It starts with the "survival decision-making mechanism," which decomposes the survivability data obtained by EAOs in northern Myanmar into three stages: data acquisition, the extent of complex social network data obtained, and the volume of such data. The survivability data linked to these cross-border networks is empirically tested using the Triple-Hurdle model. The discussion emphasizes ethnography's novel contributions to geopolitical research, showcasing its growing relevance and validity in this domain. The findings reveal that: (1) Under the influence of transaction costs or not, the impact of cross-border complex networks on the conflict's sustainability and the EAOs' resource acquisition is marked by uncertainty, negative and weak positive influences, indicating no direct and inevitable link to the conflict's persistence in northern Myanmar. (2) Transaction costs serve as a mediating factor, with their reduction not directly correlated with the data acquired by EAOs. However, the primary role of cross-border networks is to "expand" cross-border complex social networks, increase transaction frequency, and reduce uncertainty, thereby lowering transaction costs. (3) Control variables like education level, age, and livelihood status have varying impacts on data acquisition stages, showing characteristics of coexistence of positive and negative, significant differences in levels, etc. This study's integration of ethnography with complex network analysis provides a comprehensive geopolitical analysis, enriching the ethnographic geopolitical narrative of the continuous conflict in northern Myanmar.

With the rapid advancement of science and technology, artificial intelligence (AI) has become a significant force driving scientific development and social progress. In the field of geographical sciences, the application of AI technology is deepening, bringing revolutionary changes to the collection, analysis, and application of big data and spatio-temporal information, and demonstrating innovative and application potential in multiple aspects. This paper systematically reviews the development and application of AI in geographical sciences, providing a detailed introduction to the development trajectories of various AI fields such as machine learning, computer vision, natural language processing, planning systems, and large AI models, as well as their applications in geography. It discusses the problems and challenges of AI applications in geography and provides an outlook on the future development of interdisciplinary research between AI and geographical sciences.

Thermokarst lakes, as prominent thermokarst landscapes in permafrost regions, significantly influence ecological vegetation, hydrological processes, and carbon cycling in the Arctic. However, the current understanding of the distribution characteristics and change mechanisms of Arctic thermokarst lakes remains limited. To address this gap, this study employs meta-analysis and mathematical statistical methods to investigate the distribution patterns and dynamics of thermokarst lakes. The results reveal a pronounced spatio-temporal heterogeneity in the distribution and changes of Arctic thermokarst lakes. These variations are closely associated with permafrost conditions, lithology, soil types, subterranean ice content, and soil temperatures. Most Arctic thermokarst lakes are located in continuous permafrost area, where subterranean ice content exceeds 10%, average soil temperatures are above -4°C, and there are specific vertical soil temperature gradients. The change trends of thermokarst lakes differ under various environmental conditions. Generally, the development of thermokarst lakes follows three stages: initial formation, mid-term expansion, and late-stage contraction, all influenced by hydrological and thermohydrological balances. As critical indicators of permafrost degradation and climatic environmental changes, thermokarst lakes profoundly impact carbon cycling, hydrological processes, and ecological environmental changes within the Arctic ecosystem.

The empowerment of spatio-temporal information fully releases and amplifies its value as a critical factor of production, meeting the need of the era to support the high-quality development across diverse economic and social sections. Currently, foundational research into the empowerment of spatio-temporal information remains undeveloped, predominantly constrained by the perception that empowerment is synonymous with application. The lack of comprehensive understanding and investigation into its mechanism results in ambiguity in both the connotation and extension of spatio-temporal information, as well as the intrinsic mechanism of its empowerment. Such vagueness restricts the empowerment in a scientific and efficient manner. There is an immediate necessity to delineate its fundamental essence, mechanisms of empowerment, and operational modes clearly. To address the aforementioned challenges, this paper defines the foundational concept, explores the rich connotation, and outlines the essential characteristics of spatio-temporal information. It posits that entropy serves as the physical foundation for the empowerment of spatio-temporal information, with entropy decrease acting as its inherent driving force. The empowerment of spatio-temporal information utilizes spatio-temporal information as the medium, driven by the negative entropy flow, marked by the transformation of inherent uncertainty. This process enhances both the system's structure and performance through the dynamic interplay among humans, machines and the external environment. This paper describes three empowerment modes of spatio-temporal information: taking spatio-temporal information as the in-itself information for direct empowerment, employing it as the being-itself information for indirect empowerment, and converting it into spatio-temporal knowledge for enhanced empowerment. Lastly, this paper investigates the pathways through which the empowerment of spatio-temporal information contributes to the high-quality development of natural resources.

The driving force behind coordination is that the regional coordination policies can benefit the weak. Since the implementation of the Beijing-Tianjin-Hebei coordinated development policy, its actual effect has been questioned. Some negative views suggest that this policy has only benefited Beijing and Tianjin, but has not promoted the development of Hebei. In response to this question, this paper takes the implementation of the Beijing-Tianjin-Hebei coordinated development policy in 2015 as a natural experiment, using synthetic control method and panel data from 2010 to 2020, empirically evaluates the policy effect and spatial heterogeneity of this policy on economic growth, industrial structure optimization and air quality improvement of Hebei. Results indicate that: (1) The Beijing-Tianjin-Hebei coordinated development policy did not significantly drive the economic growth of Hebei, but promoted the optimization of industrial structure and the improvement of air quality, showing a trend of high-quality coordinated development. (2) The policy effect on prefecture-level cities of Hebei is different due to their distance from Beijing and Tianjin, showing a "center-periphery" diffusion pattern with Beijing and Tianjin as the core. (3) The cities close to Beijing have obtained obvious effect of industrial structure optimization, and the cities close to Tianjin have obtained obvious effect of economic growth. Cities around Beijing and Tianjin are significantly better than cities in southern Hebei in terms of air quality improvement. In the future, we need to view this policy with a new concept of high-quality development, scientifically promote the industrial transfer and undertaking within the urban agglomeration, and continuously consolidate the basic conditions for economic development of Hebei. It is also necessary to achieve spatial equity and adapt to local conditions in the Beijing-Tianjin-Hebei coordination.

Research on urban health constitutes an important issue in the field of health geography and also a strong propeller of the Healthy China Initiative. As the main form that realizes new-type urbanization, urban agglomerations should become the primal sites for the construction of a "Healthy China". The evaluation of healthy cities' development in urban agglomerations has both theoretical and practical values. Based on the concept of urban health and its evaluation models, this paper developed an evaluation framework for healthy cities that involved multiple data sources. With 19 urban agglomerations in China as the research subjects, we used CRITIC weighting and geographical detectors to examine the spatial and temporal development patterns of healthy cities and their influencing factors in 2010 and 2020. The results were fourfold. Firstly, the urban health level of China significantly increased from 2010 to 2020, and the comprehensive health index developed towards a positive skewed distribution, along with a shift from "low in the hinterland - high in the coastal areas" to a "multipolar" pattern led by the coastal and southwest urban agglomerations. Secondly, among various dimensions of urban health, the healthy environment index became improved with narrowed regional differences; while the health services index was still polarized; health collaboration was upgraded with a strengthened intercity health networks; the healthy population index slightly declined and converged to the middle. Thirdly, urban health in China has initially demonstrated the characteristics of a H-H pattern in the Yangtze River Delta and Chengdu-Chongqing regions, as well as L-L clusters in the northern urban agglomerations, the narrowed regional differences, and increasing coordination within each urban agglomeration. Fourthly, the geographical detector found that economy, urbanization and the human capital were significant external factors that affected urban health development. The explanatory power of technological innovation and openness to the outside world were also increasing. The development of healthy cities is yet to be transformed into regional health integration.

Urban shrinkage has gradually become a global economic and social phenomenon, and housing vacancy is an important concomitant effect of urban shrinkage. Housing vacancy in shrinking cities is a key issue that needs to be studied urgently. Taking Northeast China, a concentrated area of shrinking cities in the country, as the research object, this study uses multiple types of remote sensing imagery data and spatio-temporal big data to construct a shrinking city system based on the perspective of physical urban areas, estimate the housing vacancy rate, analyze the spatio-temporal variation characteristics of housing vacancy in shrinking cities, and explore the influence of housing vacancy in shrinking cities of different scales. The main conclusions are as follows: (1) During the study period, the urban shrinkage phenomenon in Northeast China is significant and the housing vacancy rate is on the rise. The housing vacancy rate is generally higher in severe shrinking cities. (2) The configuration of property facilities and the characteristics of the surrounding environment are the main influencing factors of housing vacancy. The level of urban economic development, regional transportation conditions and natural resource conditions have gradually increased their influence on housing vacancy. (3) Improving economic efficiency and increasing residents' income can help alleviate vacancy in slight shrinking cities, while severe shrinking cities need to adjust the level of property facilities and optimize the layout of transportation facilities to reduce vacancy rates.

With the continuous development and application of information technology, online shopping has emerged as a significant force, bringing immense economic potential. The convenience offered by online shopping, such as the ability to shop anytime, anywhere, and access to a vast array of products, is reshaping consumer habits and expectations. Despite the continued growth of online shopping, the role of physical stores remains significant. Physical stores offer tangible benefits that online shopping often struggle to replicate. These include the ability to see, touch, and try products before purchasing, as well as the immediacy of taking items home without having to wait for shipping. The relationship between online shopping and physical shopping remains a hot topic in academia. Although there have been relevant studies in China, most of them are based on the survey data from individual communities or cities, lacking large-scale and long-term systematic research from a national perspective. Furthermore, there is a lack of heterogeneous comparisons between different regions. Drawing on large-scale time utilization survey data of 29 provincial-level regions in 2017 and 2021, this paper analyzes the spatiotemporal evolution of online shopping behavior and physical shopping behavior of China's residents, and examines the influence of online shopping on residents' physical shopping behavior. The results show that: (1) There are significant spatial differences in the characteristics of residents' online and physical shopping behaviors. The standard deviation ellipse of online shopping and physical shopping behavior shows an obvious "northeast-southwest" distribution pattern, with the gravity center gradually shifting northward during the study period. (2) In 2017, online shopping had a significant complementary effect on physical shopping. But in 2021, both complementary and neutral effects coexisted. (3) There are significant differences in the impact of online shopping on physical shopping between urban and rural residents, and residents among different regions. There is also a coexistence of complementary effects and neutral effects. This paper clarifies the relationship between online shopping and physical shopping in China, provides an in-depth understanding of the changes of urban space in the internet era, and helps promote the spatial transformation of physical commerce.

Understanding the spatial segregation and social integration of immigrants and local residents is highly significant in summarizing the historical experience of Chinese modernization. Additionally, it serves as a crucial foundation for promoting a people-centered new urbanization, fostering spatial fairness and justice, and achieving common prosperity. However, current research on residential spatial differentiation primarily focuses on analyzing the spatial distribution characteristics, differentiation patterns, and indicator calculations of various groups, and has limited investigation into social integration issues. This paper explores this social and spatial differentiation phenomenon in Hangzhou, usingthe initial residence registration information and mobile phone signalling data to analyze the characteristics and mechanisms of living space differentiation. Additionally, this article combines a small sample of questionnaires with a bottom-up exploration of social integration under spatial differentiation. From the research, four key findings emerge: (1) The majority of residents in the city are migrants. There is a clear difference in the distribution of living spaces between immigrants and local residents, with local residents mainly concentrated in the old city area, while the distribution of immigrants is more scattered. Compared to the typical "immigrant city" in the United States, Hangzhou has less spatial differentiation between immigrants and local residents. (2) The residential space differentiation between immigrants and local residents in the city presents a combination pattern of " multi-nuclei, sectoral, concentric zone". However, unlike the centrifugal diffusion trend of the local people in the United States, the local residents in Hangzhou tends to gather towards the center, while immigrants choose centrifugal diffusion and peripheral aggregation. (3) The spatial differentiation of living spaces is mainly caused by the competition for spatial resources between immigrants and local residents under urban expansion. However, behind the phenomenon of "local residents live in the old city", immigrants are no longer a disadvantaged group. Some intelligent new immigrants actively choose to live in high-quality peripheral areas. (4) The integration between immigrants and local residents is satisfactory, but it is more cautious about the issue of intermarriage. Additionally, residential spatial segregation has not had a negative impact on social integration. There are four main reasons for this. To begin with, the majority of the population consists of immigrants, and urban residents no longer pay attention to identity labels in their daily interactions. Besides, there is relatively little cultural difference within ethnic groups, and the assimilation between immigrants and local residents is increasing. And then, interactions between individuals in workplace and third place can alleviate the negative impacts caused by residential spatial segregation. Finally, China's coordinated development and people-oriented social system can also create favorable conditions for social integration.

The mass elevation effect (MEE) is a thermal phenomenon associated with uplifted landmasses, leading to spatial differentiation in water-heat assemblies that profoundly affect the geo-ecological pattern and environmental evolution of mountains and regions. This study developed a ground-air temperature regression model to simulate the temperature distribution on the Qinghai-Tibet Plateau using MOD11C3 data and meteorological observations, analyzing the spatiotemporal diversity and dynamic evolution of the MEE across the entire plateau and internal landform regions were estimated and analyzed from 2000 to 2019. Employing the Geodetector method, the research uncovered the genesis patterns of the MEE at different scales, revealing an average MEE of 4.13 ℃ with a pronounced centripetal pattern from northeast to southwest and decreasing elevation-dependent characteristics that were significantly negatively correlated with longitude and latitude. The average MEE of the landform regionalization was 5.06 ℃, indicating a stronger internal spatial differentiation within landform regionalization. Seasonally, the MEE was slightly stronger in the dry season, with distinct patterns of weakness in the northwest and strength in the southeast during the dry season, and the opposite in the wet season. The MEE showed an asymmetric linear enhancement pattern under global climate change, with an inclination rate of 0.26 ℃/10 a, presenting a "ring-like" characteristic of strong in the east and weak in the west and decreased from the hinterland core to the edge. The weak areas were significantly enhanced, whereas the strong areas showed small variations. The MEE fluctuation magnitude and change rate were both stronger in the dry season than in the wet season, with the dry season primarily contributing to MEE changes. The spatial and temporal patterns of the MEE were influenced by scale effects, with latitudinal zonation at the macroscale and microtopographic features at the regional level. Moreover, NDVI and barometric pressure were found to enhance the seasonal spatial variations of the MEE. This comprehensive analysis provides deep insights into the mountain science and responses to climate change.

Soil erosion is influenced by various factors, such as land use and climate change. The Wangmaogou watershed, as a typical area for soil and water conservation in the hilly and gully regions of the Loess Plateau, has implemented a series of measures since the 20th century, including the Grain for Green Project. This study evaluated the spatial and temporal evolution characteristics of soil erosion intensity in the watershed in the years of 2010, 2015, and 2020 using the CSLE model. It also studied the situation of land use/cover change (LUCC) to analyze the spatial distribution patterns of land use and the responses of soil erosion in different time periods, thereby verifying the effectiveness of the soil and water conservation measures. The results revealed that from 2010 to 2020, the annual average soil erosion modulus in the study area decreased by 0.11 t hm^-2 a^-1, indicating a slight improvement in overall soil erosion conditions. However, the proportion of slight erosion decreased by 5.56%, while severe erosion increased by 4.02%, with the higher erosion zone mainly distributed in the northern, central, and northwestern parts of the watershed. Compared to the year 2010, soil erosion conditions in the watershed were greatly relieved in 2015 due to the decrease of rainfall and restoration of vegetation, but rebounded in 2020 resulting from the extreme rainfall events and declining vegetation cover quality. From 2010 to 2020, there were significant conversions between grassland and farmland in the northern and northeastern parts of the watershed. The decline in grassland quality resulted in a higher average soil erosion modulus compared to farmland, at 13.69 t hm^-2 a^-1 and 12.99 t hm^-2 a^-1, respectively. This study would contribute to figuring out the relationship between soil erosion in typical small watersheds of the Loess Plateau, extreme climatic events, and land use changes, providing scientific data support for future efforts to improve soil and water conservation benefits and mitigate soil erosion risks.

In the context of the increasingly severe global food crisis caused by multiple external factors, building a more productive, nutritious, resilient, and sustainable food security system to promote the transformation of the agricultural and food system had become more crucial, particularly because it is essential for stabilizing China's overall economic and social development. This paper was based on the perspective of the Nature-Society-Economy complex system. It divided the food security system into three levels: resources and environment, production and supply, and distribution and consumption. This paper constructed an index system based on the three-dimensional framework of Pressure-State-Response, employing provincial panel data from 2000 to 2021 to analyze the spatial and temporal spatial evolution characteristics of China's food security system transformation. A dynamic panel model was adopted to quantify the various driving factors related to the food security system transformation. The research results indicated the following: (1) The comprehensive index of food security system transformation from 2000 to 2021 increased by 97.90%, showing a two-stage change characteristic with a moderate rise from 2000 to 2012 and a rapid growth from 2013 to 2021. The transformation index of the resources and environment and the production and supply subsystems were consistent with the evolution of the comprehensive index of food security system transformation, also exhibiting a two-stage upward trend. The transformation index of the distribution and consumption subsystem showed a downward and then an upward trend. (2) The comprehensive index of provincial food security system transformation increased continuously from 2000 to 2021. The provinces that exceeded China's average shifted from a balanced distribution across the eastern, central, and western regions in 2000 to clustering in the main grain-producing areas in 2021. (3) The food security system transformation is an ongoing endeavor. The rate of urbanization, agricultural financing policies, birth rate, and dietary diversity index can significantly promote the transformation of the food security system. The transformation of the food security system can be seriously hampered by industrialization, relative returns from agricultural production, GDP growth rate, and per capita disposable income.

Quantifying the contributions of climate change and human activities to changes in vegetation is important in terms of regional ecological protection and future research on the Loess Plateau. However, in the case of areas with naturally regenerated vegetation, where there are no clearly visible indications of human activities and ecological processes are not significantly disturbed, not all relevant forms of human activity can be remotely detected. Therefore, modelling the intensity of human modification of natural ecosystems could provide a pathway for a better understanding of the questions concerning where and how much vegetation change occurs in areas with evidence of human activities or land-use change. In this study, we utilized the Normalized Difference Vegetation Index (NDVI) between 2000 and 2022 and land-use datasets (a spatial resolution of 30 m) collected in 2000, 2010, and 2020 to distinguish areas with strong and weak anthropogenic interference on the Loess Plateau. In those areas with clearly visible human activity, we explored the relative contributions of climate change and human activity to vegetation dynamics. Taking the lagged duration variation between climate factors and vegetation growth into consideration, climatic factors influencing vegetation decadal dynamics were identified in the southern part of the Loess Plateau. The results are as follows: (1) With the implementation of the Three-North Shelter Forest Program, Grain-to-Green Program, and other ecological projects, the rate of vegetation restoration on the Loess Plateau slowed by 3.4%/10a during the period 2012-2022; however, the overall trend was an increase in vegetation. (2) In sensitive areas of vegetation restoration in the Loess Plateau, human activities with a relative contribution exceeding 65% were the dominant factors of vegetation variability in the areas with both intensive and weak human interference, which is approximately 2.0-fold higher than the contribution of climate change. (3) The interdecadal anomalies of precipitation in June were effective indicators of opposite west-east vegetation anomalies in the southern part of the Loess Plateau. Specifically, when precipitation increased by 10 mm in June, this southeastern part witnessed a decrease of 1.4% in NDVI in contrast with a 1.7% increase in the southwestern part. By coupling temporal and spatial information we have clarified the spatial distribution of trends and decadal variations in NDVI and its influencing factors. These observations from the Loess Plateau provide useful insights to help understand the relationship between vegetation change, climate change, and human activities on vegetation restoration globally or in other regions of China.

Glacial meltwater is a major carrier of nutrients and bioactive compounds, and meltwater chemistry is an important way to study the glacier drainage system and its dynamic characteristics to gain insights into the biogeochemical cycling process and explore the relationship between deglaciation and climate change. With accelerated melting of glaciers and increases in erosion and weathering, meltwater chemistry has undergone significant changes, which may have significant impacts on downstream water quality, the water environment, and ecosystems. In this study, the contents of inorganic chemical components and their spatial and temporal variations, solute sources and their proportions, and the relationship between chemical weathering and carbon cycling in global glacial meltwater were reviewed. The results indicated that meltwater chemistry is affected by various factors, such as the nature of the bedrock, the drainage system, the physical chemistry, and the topography and geomorphology. To provide references for future research on the relationships among the cryosphere, carbon cycle, and climate change, it is essential to strengthen simultaneous and continuous monitoring of hydrometeorological parameters and inorganic and organic chemical components in meltwater, evaluate the ecological and environmental effects of solutes sourced from glaciers, and examine the relationships among the coupled mechanisms of chemical weathering in glacial regions, solute mobilisation, and atmospheric CO₂ balance.

In the wake of unprecedented global urbanization, an alarming trend of shrinking cities has emerged worldwide, presenting a profound challenge to conventional urban-regional planning approaches, primarily centered on growth scenarios. This trend has also bestowed upon Chinese geographers and urban and rural planning practitioners a new mandate in this evolving era. One region that exemplifies this predicament is Northeast China, experiencing the most severe population decline and the highest concentration of shrinking cities in the country. How to rationally recognize and properly deal with this phenomenon (or problem) of regional urban shrinkage has become the core scientific issue to be focused on in the comprehensive implementation of regional coordinated high-quality development, Chinese-style modernization of common prosperity for all and all-round revitalization of Northeast China in the new era. This paper delves into a logical speculation and practical discussion to understand the underlying causes and implications of regional urban shrinkage in Northeast China: Initially, it examines the original concept of regional shrinking cities within the context of urbanization, critically evaluating the rationality of such shrinkage in light of the broader national strategic objectives. Subsequently, the generation logic of regional urban shrinkage in Northeast China is explored through three key factors: the "pull" effect of regional spatial correlation, the "extrusion" effect of urban shrinkage at a regional level, and the "catalyst" effect of transportation and communication technology development in reducing the cost of factor flow. Moreover, this study draws on the market-led shrewd contraction theory and the government-led vitality regeneration governance logic. It takes into account the governance objectives of achieving "regional coordinated high-quality development, people-oriented new urbanization, efficiency and fairness, and comprehensive security concept". With a systematic perspective that considers scale heterogeneity, development context relevance, factor differentiation, and multidisciplinary integration, the paper outlines a governance model and strategy for addressing regional urban shrinkage in Northeast China. By emphasizing the alignment of governance approaches with national development goals, this research underscores that regional urban shrinkage goes beyond a mere outcome of market-driven population migration. The presence of underlying "market failures" severely impacts the vision of the five major securities (national defense, food, ecology, energy, industry) advocated by Chinese President Xi Jinping for the Northeast China region. The findings of this study offer valuable insights to guide Northeast China's pursuit of high-quality development and contribute to the region's revitalization efforts.

In the post-Cold War era, the global landscape has evolved towards multipolarity, and the geostrategic behavior of states has gradually shifted away from the traditional binary model of "balancing-bandwagoning" to a more flexible and diverse one called hedging strategy, and it is the current strategy that the countries surrounding the South China Sea have adopted in response to China's actions. By introducing the hedging theory of international relations, we seek to understand, from a geopolitical perspective, how these geopolitical entities employ hedging strategies. First, an analytical framework is constructed to theorize hedging strategy, consisting of driving factors, mediating factors, and strategic choices. Second, the hedging intensity is assessed quantitatively via the geopolitical risk and the relative power index of the countries surrounding the South China Sea. The evolution of it is presented through a bivariate visualization method, and the various hedging patterns are classified by utilizing the quadrant diagram. Finally, both the theoretical framework and quantitative outcomes are validated by analyzing the strategic practices of the study region. We conclude that: (1) the geopolitical risks of the countries surrounding the South China Sea have been "tending to be stable but difficult to achieve" since the beginning of the 21st century, with significant heterogeneity among these countries. The evolution of state relative power exhibits a fluctuating trend, closely linked to U.S. intervention. (2) The hedging intensity of the countries surrounding the South China Sea results from the interaction between geopolitical risk and state relative power, leading to three distinct forms, represented by Vietnam and the Philippines, Indonesia, and Malaysia and Brunei, respectively. (3) The intrinsic logic of the hedging strategies of these countries can be seen as a strategic cognition shaped by their threat awareness and national strategic orientation. This cognition then orientates diverse hedging approaches that guide these countries in applying either cooperative or competitive tools. By understanding the intensity and nature of the strategic hedging by the countries surrounding the South China Sea, we aim to provide a unique vantage point for China's regional governance in the South China Sea.

To achieve sustainable economic development and promote the comprehensive green transformation of the economy and society, it is necessary to improve ecological welfare performance. This study constructed a method of quantitatively evaluating ecological welfare performance in China based on residents' welfare and ecological consumption. On this basis, the ST-LMDI model was used for spatial and temporal decomposition of the ecological welfare performance of provincial-level regions and economic zones in China, thus expanding the current research on the decomposition of the driving factors of ecological welfare performance. The results of the study were as follows. First, the trend for China's ecological welfare performance from 2001 to 2020 was first increasing and then decreasing, with significant regional differences. Additionally, because of their advantages in socioeconomic structure and livelihood-based fiscal expenditures, the coastal regions had a higher ecological welfare performance and also showed spatial spillover effects. Second, the six factors of social benefits, economic benefits, population dispersion, population density in built-up areas, scale of urbanization, and ecological sustainability were introduced to explore their driving roles on ecological welfare performance. The findings showed that the spatial and temporal decomposition results were significantly different. The temporal decomposition results proved that economic benefits and scale of urbanization were the main factors promoting ecological welfare performance, whereas population dispersion inhibited growth of ecological welfare performance. However, the spatial decomposition indicated that the drivers that determine above-average ecological welfare in each provincial-level region showed regional differences and dynamic changes in different periods. The combination of spatial and temporal decomposition and the relationships among economic growth, ecological conservation, and enhancement of residents' welfare are comprehensively helpful to provide reference for local governments to formulate and implement differentiated policies.

This paper aims to examine the characteristics and patterns of the spatial linkage networks of urban economic efficiency so as to provide new policy insights into the regional integration process. The study builds a theoretical framework to analyze the spatial linkage of urban economic efficiency among cities from the perspective of scaling law. It constructs an analytical paradigm to reflect the network externalities. The Yangtze River Delta Urban Agglomeration (YRDUA) is selected as a case study, and the improved gravity model and social network analysis are applied to measure the urban economic efficiency from 2000 to 2020, analyze the strength of inter-city linkages, and construct a spatial linkage matrix. The results reveal that: (1) the high economic efficiency zone of the YRDUA is gradually shifted from the high-grade cities in the east to the low-grade cities in the northwest; (2) the high-grade cities occupy a central position in the network, forming solid links and "small groups" with the neighboring cities; (3) in the linkage pattern of the urban agglomeration, the Shanghai-Suzhou, Hangzhou-Ningbo, and Hefei clusters show a dual-center, radiation-type and siphon-type coexistence. In contrast, the Nanjing cluster shows a single-center radiation pattern. The linkage paths of the cities in these four clusters are relatively fixed, and the linkage patterns evolve slowly. These findings coincide with the theory of city "quality" in urban geography and the theory of city links in economic geography, and provide empirical support for the integrated and coordinated development of the YRDUA, as well as emphasize the importance of the coordinated development pattern of the "wild goose" echelon structure, which is essential for the understanding of the development of the YRDUA.

This study explored spatial characteristics of and spatial relationships between "townization" and transportation advantages in 2460 small towns in the Yangtze River Delta. Bivariate spatial autocorrelation was used to reveal how transportation has impacts on "townization". It is found that: (1) The overall development of "townization" in the study region is in the early to mid-term stages, with over 50% of towns having a "townization" level of less than 30%. There was significant spatial differentiation in transportation advantage, with advantages decreasing from a central point outwards: Shanghai acted as the primary center, Suzhou-Wuxi-Changzhou, Hangzhou, Ningbo, and Hefei were secondary centers, and underdeveloped city outskirts and the border area of Anhui acted as the peripheral layer. (2) The level of "townization" showed a general coordination with transportation advantage, whereas simultaneous low levels of both predominated and coordination decreased with increasing distance from central urban areas. Developed areas, such as Shanghai and Suzhou-Wuxi-Changzhou, contained small towns with developed transportation but relatively low "townization" level. In contrast, underdeveloped areas, such as Northern Jiangsu and Anhui, contained small towns with high population densities despite low transportation advantage. (3) Transportation had a significant positive impact on "townization". (4) While location factors generally promoted "townization", some specific factors had negative impacts. Both positive and negative effects of location factors were more pronounced in more developed areas. Transportation accessibility primarily promotes the transfer of goods and services and technologies between core cities and surrounding towns through spatial spillover, thereby reshaping the economic advantage of small towns and increasing population density. The concentration degree of the road network mainly affects the population density of towns by influencing travel costs and the speed and scale of movement of goods and services.

As an important subsystem describing rural development, the mutually beneficial symbiosis of rural settlements and cultivated land is crucial for sustainable rural development. Under the heterogeneous physical environment of Gansu province, 1384 townships were taken as the research units, and the symbiosis theory was introduced to construct a framework for the symbiosis between rural settlements and cultivated land. We construct a system of indicators for evaluating rural settlements, cultivated land, symbiosis environments, and identify their symbiosis patterns with the help of the Lotka-Volterra model. In the context of the new round of territorial spatial planning, the SD-FLUS coupled model is used to compare and analyze the evolutionary trends of symbiosis patterns under the baseline development scenario (BD) and the planning development scenario (PD) in 2035. The study found that: (1) The development level of rural settlements and cultivated land in Gansu shows a trend of first increasing and then decreasing, and the symbiosis environmental capacity shows a continuous decreasing trend. Three indicators of the five agricultural zones have significant differences. The irrigated agriculture area of the Hexi Region (IA) has an obvious advantage in the regional development. (2) The overall pattern of symbiosis between rural settlements and cultivated land in the province showed a shift from mutually beneficial symbiosis to mutually detrimental symbiosis, with the proportion of mutually beneficial symbiosis decreasing from 59.80% to 38.97%. There were significant differences in dominant patterns between regions. Alpine pastoral area (AP), mountainous agricultural area (MA), and IA are dominated by mutually beneficial symbiosis, while dry agricultural area (DA) and rain-fed agricultural area (RA) are dominated by rural settlements-bias and cultivated land-bias. During the 21-year period, the dominant pattrens of each region tended to be diversified and showed a commonality in the transformation from mutually beneficial symbiosis to mutually detrimental symbiosis. (3) The symbiosis relationship between rural settlements and cultivated land varies significantly under different scenarios. In the BD scenario, the five regions continue the historical rough development pattern, and the proportion of mutually beneficial symbiosis continues to decrease. In the PD scenario, the symbiosis pattern evolves to mutually beneficial symbiosis due to the improvement of symbiosis unit and environmental development level.

This research aims to decipher the patterns and mechanisms of surface water recharge during the rainy season in plateau mountain-lake region. Based on the stable hydrogen and oxygen isotope data of multiple water bodies collected in the Erhai Lake Basin from July to August 2022, and using Bayesian mixing models and remote sensing technology, the study quantifies the sources and proportions of surface water recharge and explores water body transformation mechanisms. The results indicate that: (1) Precipitation in the Erhai Lake Basin during the rainy season is influenced by evaporation and monsoon climate, resulting in hydrogen and oxygen isotope values that are more negative compared to groundwater and surface water. Groundwater δD and δ¹⁸O indicate that in areas of high altitude and high water richness, the hydrogen and oxygen isotope values of groundwater are more negative, while d-excess values reveal evaporation differences among different aquifer groups. The hydrogen and oxygen isotope values of surface water gradually become more positive as the water flows from inflowing rivers through Erhai Lake to outflowing rivers, with the isotope values on the eastern slope and southern region of Cangshan Mountain being more positive compared to the northern region. For the eastern slope of Cangshan Mountain, the midstream area shows the most significant evaporation. (2) The spatial pattern of surface water recharge sources between Cangshan Mountain and Erhai Lake shows that surface water contributes the most to its downstream mixed water bodies. The contribution rate of precipitation and surface water in each river section between Cangshan Mountain and Erhai Lake is shown as follows: the contribution rate of precipitation and surface water in the river section above the mountain outlets is smaller than that in the river section below the mountain outlets; while the contribution rate of groundwater is vice versa. (3) Along the river flow direction, the spatial pattern of surface water recharge sources is jointly influenced by topography, geological conditions, surface cover, and water vapor characteristics. Areas with good vegetation cover, high surface temperatures, and high actual evapotranspiration receive more precipitation recharge; areas with relatively poor vegetation cover receive more surface water recharge and the contribution rate of groundwater to surface water depends on the type of aquifer groups.

To quantitatively explore the adjustments in the wandering intensity in a wandering reach of the Lower Yellow River (LYR) since the operation of the Xiaolangdi (XLD) Reservoir, the calculation method of a new wandering index (WI) was proposed. In addition, Landsat images were collected to perform an analysis of the spatio-temporal variations in the wandering intensity and their response to major influencing factors. The results indicate that the wandering intensity in the wandering reach integrally presented a decreasing trend during the period from 2000 to 2022, with the value of WI decreasing from 0.918 to 0.674 and changing rate being fast to slow. Specifically, the wandering intensity in the Tiexie-Yiluohekou reach and Huayuankou-Jiahetan reach has decreased, while the Yiluohekou-Huayuankou reach maintained and the Jiahetan-Gaocun reach increased. Furthermore, the wandering intensity adjustments had close relations to the flow-sediment regime, riverbed boundary conditions and local river regime evolution. For flow and sediment regime, the decrease of wandering intensity in the wandering reach was significantly attributed to the sharp reduction in the incoming sediment volume and rising-recession rate of floods in the LYR owing to the operation of XLD Reservoir, which resulted in the riverbed erosion and flow concentration in the downstream channel. Regarding riverbed boundary conditions, the wandering intensity in the sub-reaches with strong lateral restrict caused by banks or channel regulation works tended to decrease. Also, the increase in the longitudinal stability of the riverbed was one of the reasons why the wandering intensity in the wandering reach declined with a slower changing rate in the later stage. Concerning about propagation of river regime adjustments, the frequent occurrence of avulsion in the Jiahetan-Gaocun reach during the later period was mainly attributed to the river regime evolution in the inlet reach between Zhuzhai to Dongbatou.

Waterlogging, water pollution, black and odorous water, and riverine and lacustrine ecological degradation are the main water problems faced by China's cities, which have become one of the key obstacles to the green development of the Yangtze River Economic Belt. In-depth understanding of the evolution of the water system in the process of urban development and the mutual influences between the elements, clarifying the formation mechanism of the urban water problems, and constructing an integrated treatment technology system of the urban water system are the fundamental ways to solve the complex urban water problems. Aiming at the abovementioned urban water problems, this paper summarizes the concepts and characteristics of the urban water system from a systematic perspective of the multiple processes coupled with each other in the water cycle and proposes a key technology system for a systematic solution to the urban water problems, which are demonstrated with the treatment examples of the urban agglomeration in the Yangtze River Economic Belt in 2016-2022. The demonstrative applications show that the pumping stations and sponge measures can effectively reduce the severely inundated area of Wuhan city in extreme rainfall events and eliminate the waterlogging points in the Chengdu-Chongqing urban agglomeration; the proposed microbial-botanical-hydrodynamic integrated synergistic regulation and control technology can significantly enhance the removal efficiency of the nitrogen and phosphorus level in typical black and odorous water bodies of Wuhan city; the proposed source control-path dissipation-terminal regulation comprehensive ecological treatment system for urban rivers and lakes decreased the water eutrophication level significantly in the Lianghe River basin of Chongqing city; with the implementation of the abovementioned treatment technology system, the green development index of the urban agglomeration in the middle reaches of the Yangtze River increased by an average of 4.8%. This study provides theoretical and technical support of urban water system for the major strategies of the green development of the Yangtze River Economic Belt.