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.

Sustainable development is a significant scientific issue of global concern. Geography, as a comprehensive discipline focusing on the coupled relationship between human activities and the natural environment, provides systematic research and solutions for achieving the United Nations Sustainable Development Goals (SDGs). However, there is currently a lack of comprehensive reviews. This paper summarizes the theoretical framework and research progress of Geography supporting the SDGs and explores its future key research areas. This article indicates that: (1) Geography, in conducting integrated research on human-nature systems and serving regional and global sustainable development processes, has innovatively proposed and developed theoretical frameworks such as social-ecological systems, pattern-process-service-sustainability, metacoupling, and Classification-Coordination-Collaboration. These research frameworks include elements of human-environment system interconnections, process coupling, spatial coupling, and systematic regulation oriented towards SDGs, forming a comprehensive theoretical framework supporting sustainable development research in Geography, also referred to as "sustainable geography theoretical framework". (2) Geography has made positive progress in supporting the United Nations SDGs research in areas such as multi-source data acquisition, localization of indicator systems and multi-scale progress assessment, analysis of inter-target linkage mechanisms, and SDG achievement pathways. Geography provides important theoretical and methodological support for SDG research. (3) Geography and sustainable development-related research mainly focus on climate-ecological crisis response, sustainable utilization of food-energy-water resources, regional development and planning, human well-being and social governance, and the construction of SDG assessment indicators and databases. (4) In future research, there is a need to innovate and develop sub-disciplines of Sustainable Geography, optimize the construction of SDGs indicator systems, develop SDGs assessment and decision-making models, strengthen artificial intelligence geography, deepen research on human-nature system coupling, and promote regional and global sustainable development in the process of advancing innovation in the discipline of Geography.

As an important aspect of the notion that "spatial is special", spatial heterogeneity has been a central topic of geospatial analytics. It is also closely related to the methodological tradition of geography and replicability of geographic research. The emergence of fine-grained big geospatial data and the development of Geospatial Artificial Intelligence (GeoAI) have brought new opportunities and challenges to spatial heterogeneity modeling. Spatial heterogeneity may refer to (1) values of geographic variables; and (2) associations, or the generation process of geographic variables, which correspond to data and process heterogeneity, respectively. Moreover, the specification of spatial heterogeneity may be categorized as continuous and discrete. Based on the dichotomies above, we summarize the main scenarios of spatial heterogeneity modeling and review corresponding methods: (1) homogeneity-based regionalization; (2) local spatial regression; and (3) spatial regime regression. In particular, we discuss approaches to delineate spatial regimes in an endogenous manner. We also review related methodological advances in GeoAI, where the principle of spatial heterogeneity is reflected in the design of neural network models. Finally, we point out several potential directions for future research. As emerging directions in spatial heterogeneity modeling, spatial regime regression and GeoAI methods need more attention from researchers.

The new wave of technological revolution driven by artificial intelligence (AI) has become a competitive advantage pursued by countries worldwide, and it is also expected to bring about significant innovations in urban geography. This paper reviews the development trajectory of AI and proposes a conceptual model of the urban human-environment system oriented towards AI. It systematically outlines and summarizes the involvement of AI in urban geography research from four perspectives: data representation, scenario applications, spatial transformations, and urban development. Additionally, it identifies the challenges, contexts, exploration paths, and future prospects faced in the intelligent transformation of academic disciplines. The study finds that: (1) The interactions between elements within the urban human-environment system oriented towards AI are becoming increasingly complex. (2) The trend of AI becoming a primary tool in urban geography research is increasingly evident, offering high efficiency, low cost, and strong learning capabilities in data processing. This has significant implications for spatial perception and intelligent decision-making. AI has sparked spatial transformations, not only creating complex virtual spaces but also reconstructing social spaces. Additionally, AI supports the development of smart cities and the establishment of cutting-edge urban application platforms. (3) Urban geography research in the context of intelligent transformation faces challenges related to data and technology, as well as the broader contexts of global and local changes, technological ethics, and the development of humanistic values. Future development paths could explore overcoming technical barriers, focusing on urban spatial construction and governance, and emphasizing the research on the effects of multiple intelligence shifts. The discipline urgently needs comprehensive transformation and upgrading.

Metropolitan areas are pivotal in driving national economic growth, advancing harmonious regional development, and participating in competitive international collaboration. Consistent with international consensus, China's planning policies define metropolitan areas as a one-hour commuting circle. Simultaneously, these planning protocols particularly highlight the importance of industrial specialization and intercity collaboration, with the objective of developing modern urban agglomerations characterized by a well-defined spatial structure, complementary urban functions, and an integrated industrial division. This study uses the 2017 intercity input-output table analysis to examine patterns of industrial division and functional synergy in Chinese metropolitan areas. The findings are as follows: (1) From the perspective of industrial division and functional synergy, Chinese metropolitan areas can be categorized into four distinct spatial structures: the single-center dispersed structure, the core-periphery structure, the peripheral expansion structure, and the multi-center network structure representing an advanced phase in the spatial evolution of metropolitan areas. (2) The spatial network of industrial chains in Chinese metropolitan areas is predominantly governed by the flow of processing and manufacturing links. There is a substantial gap in the processing and manufacturing links between the Beijing and Tianjin metropolitan areas compared to similar types of metropolitan areas, and there is considerable potential for enhancing the productive service links in the Guangzhou, Chengdu, and Changsha-Zhuzhou-Xiangtan metropolitan areas. (3) The essence of transforming Chinese metropolitan areas into functionally complementary industrial cooperation areas is to further refine the spatial network of the industrial chains, strengthen functional synergy between cities, and encourage spatial integration in the metropolitan areas. (4) Single-center dispersed structure metropolitan areas, including Shijiazhuang, Chengdu, Wuhan, and Changsha-Zhuzhou-Xiangtan should initially transition toward a core-periphery structure. In contrast, peripheral expansion structure metropolitan areas such as Nanjing and Hangzhou metropolitan areas, and core-periphery structure urban agglomerations such as Tianjin, Shenzhen, Guangzhou and Beijing metropolitan areas should progress toward a multi-center network structure.

The physical geography and hydroclimatic conditions in the arid region of in northwestern China leading to diverse flood-generation mechanisms. Under the influence of global and regional climate change, the spatiotemporal variation of floods and flood-generation mechanism in this region is still unclear and restricts flood prevention and mitigation and the implementation of the Belt and Road Initiative in the major regions. Based on the series of the annual maximum flood peak discharge in 58 river basins in the study area from 1961 to 2017, we analyzed and revealed the mechanisms, spatial distribution and interannual variation characteristics of flood in the basin in the past 60 years based on statistical tests and machine learning approaches. The results show that the frequency of extreme floods and the annual maximum flood peak discharge magnitude are increasing, with the maximum increase in the frequency of extreme floods at about 0.84 times/10 years, and the maximum increase in the annual maximum flood peak discharge magnitude at about 29%/10 years compared with the multi-year average, and the largest increase is mainly observed in the eastern Tianshan Mountains and the Qilian Mountains. There are three main flood generation mechanisms, i.e., rain (R), snow (S) and mix (M), the frequency of R and M floods increased significantly, while the frequency of S floods decreased. The contribution of flood mechanisms transformation to the increase of annual maximum flood peak discharge magnitude can reach up to 38%, which is significantly higher than the contribution of a single hydrometeorological factor such as precipitation. The results of this study emphasize the importance of attributing and predicting the changes of flood characteristics in geographically complex region from the perspective of flood mechanisms. Engineering hydrological design in the changing environment also needs to consider the influence of the heterogeneity of flood samples caused by different flood mechanisms on the flood frequency analysis, so as to provide scientific support for flood risk management and response in the basin.

Energy is pivotal for the operation of the global economy. It is thus critical for us to elucidate the characteristics and dynamics of the global energy industry during the process of transformation in the 21st century. Using the input-output data by the United Nations from 1990 to 2022, this study gauges the added value of the energy industry of 184 countries and regions in the world and seeks to show its distribution, asymmetric dependency, and key drivers across different industrial stages. (1) We find the value of the global energy industry grew slowly at first, then rapidly, followed by slowly again, and ended up a recession during the period covered in our analysis. This temporal trend corresponds to the cycle of the global economy for each decade. (2) Energy small countries exhibited growing dependence on energy superpowers, and likewise interdependence among energy superpowers also increased, especially in the stage of prospecting and exploitation. This signifies that our world has gradually become an interconnected community of economic coexistence and co-prosperity. (3)We saw the rise of China, Russia, Saudi Arabia, and other countries as they gradually became the chain leader and hubs of the global energy industrial network. Their rise also has made the boundaries of cooperatives blur and the hierarchy of power iterate. The post Cold-War world is evolving from a unipolar one dominated by the United States into a multipolar one, and the global energy order is experiencing a profound reorganization. (4) Interdependence on the energy industry is a result of differences in attributes among countries (regions), their relative advantages, and their multidimensional proximity. Trade gaps, disparities among coporates, shared languages, colonial histories, and global organizations strengthened their interdependence, whereas geographic distance acted as a significant negative factor. Both economic gaps and institutional environments did not make any significant differences in shaping energy dependence. The role of these factors vary across different industrial stages over time.

Alluvial fans are common fan-shaped depositional landforms that develop at the outlets of mountain rivers or gullies. Mature and stable alluvial fans are important areas for both human habitation and production in mountainous regions, but they also pose potential hazards associated with flash floods and debris flows. Research on alluvial fans enhances our understanding of regional environmental dynamics and geomorphic evolution, as well as contributes to the mitigation of flood and debris-flow hazards. Therefore, it holds significant scientific value and practical importance. Although considerable research has been conducted on alluvial fans, both domestically and internationally, in recent decades, much of it has focused on geomorphology (morphometry), sedimentary history and characteristics, and historical environmental reconstruction (or inversion). Investigations into the mechanisms of fan development and their geomorphic effects remain relatively underexplored. This review systematically summarizes the key advancements in the research on the dynamic processes, mechanisms, and morphodynamics of alluvial fan development. We first provide an overview of current technical approaches applied in the study of alluvial fans, including field investigations and model experiments. Then, we summarize four critical aspects of fan dynamics processes and development mechanisms: primary and secondary processes; mechanisms of flow channel avulsion; interactions between tributary and main rivers; and the impact of alluvial fan development on sediment production, transport, and geomorphic processes. Finally, we discuss several areas that require further attention in future research. Currently, field observations and monitoring of the dynamic processes of alluvial fan development are inadequate. As an essential complement to post-event field surveys and experimental model research, there is an urgent need to enhance field observations in order to expand and deepen our understanding of alluvial fan development mechanisms. This will promote scientific insights into sediment dynamics and geomorphic processes within regional river systems.

Amid the increasing global uncertainties, studying the risk structure and resilience level of global supply chains for agricultural products highlights their importance. It not only provides China with a scientific foundation for better utilizing international markets and resources and ensuring the safety of agricultural product imports, but also promotes the development of risk resilience management theories and methods for typical products across geographical spaces, thus expanding research in resource geography. This study builds a framework that consists of three sectors (export sectors, logistics and transportation sectors, and import sectors) and four stages (supply, procurement, transportation, and demand). Using two-stage DEA and CoDEA models, it evaluates the supply chain risks and resilience of soybeans, which is the typical import-dependent agricultural product in China. The findings indicate that: (1) The risk of China's imported soybean supply chain increased from 2000 to 2020, with risks predominantly from the demand and procurement stages. By contrast, the supply and transport stages are less risky but significantly increased. Trade relations with exporting countries and economic policy uncertainty are the main long-term risk factors that threaten the security of soybean import supply chains. (2) China's soybean supply chain from Brazil is more resilient than that from the US and Argentina, suggesting great potential for improving supply chain cooperation with Brazil. (3) Making the distinction between short- and long-term threats is necessary for managing the risk resilience of the global soybean supply chain. Improving the capacity to react to sudden hazards represented by trade restrictions, maritime obstructions, and trade sanctions should be the priority in the short term. Long-term exploration of system construction and strategic layout optimization is necessary to improve the discursive power of the supply chain.

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.

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.

In recent years, the tidal limit of the lower reaches of the Yangtze River has shifted upward, the construction of water-related projects has increased, and the intensity of river bank failure disasters has been on the rise. Previous researchers have found the existence of strong vertical-axial backflow in the bank failure section through field surveys, physical modeling, and numerical simulation, and that there is a strong vertical-axial backflow in the bank failure section; however, the hydrodynamic zone characteristics of the bank-channel interactive zone and the microgeomorphic adaptation mechanism have not been explored. Based on the Doppler acoustic current profiler (ADCP) in the frequent bank failure sections, multibeam system, combined with previous high-resolution underwater topographic data, it is found that the flow velocity and flow direction in the interactive zone of the bank-channel have significant zone characteristics, and according to the backflow strength \alpha, i.e., the longitudinal flow velocity u and its ratio to the transverse flow velocity v, |u/v|, the zone from the channel to the bank is identified into the main stream zone (α<1, u>0), the mixing zone (α≥1), and the near-bank backflow zone (α<1, u<0). The mainstream zone develops large and medium-sized dunes, scour grooves, and scour pits, the mixing zone develops accumulators and small dunes, and the backflow zone develops spines and small dunes; the main stream direct flushing in the mainstream zone and the backflow lateral erosion in the backflow zone are the main driving forces for the development of scouring microgeomorphic type and the development of bank failures, and the high flow velocity gradient in the mixing zone near the main stream zone generates scouring geomorphology, and the remaining part of mixing zone remains a low flow-velocity to make the sediment fall and silt to form the accumulation body. The findings can provide important references for the disaster remediation and near-shore engineering design and monitoring.

The advent of information intelligence and spatiotemporal big data have significantly broadened the scope of application for geographic information systems (GIS), presenting both opportunities and challenges in the modeling of geographic scenarios. Current paradigms for organizing spatiotemporal data and conceptualizing spatial cognition predominantly rely on a bottom-up approach, which was demonstrated with limitation on low cognition and the fragmented representation of geospatial objects. This is a noteworthy research issue facing the Big Data era, namely the design of new representation models for the integration of objects and knowledge, as well as the collaborative computation of models and objects. This study, inspiring from Leibniz's relative spatiotemporal perspective, establishes an object space-based approach for organization and management of geographic scenarios. The concept of object space was proposed by reviewing the historical evolution of geographic scenarios representation model and literature work on mainstream research domain. Object space is the space of influence of an object, both the inner space of the object and the space of its surroundings. It includes pan spatiotemporal object, object space relationship, calculation and analysis process, which represents object, knowledge and model. For representing and management of object space, a hierarchical model was developed to organize pan spatiotemporal objects according to business requirement and spatial scale. Further, a network model was denoted to represent object space relationship and knowledge, in which node is the objects, and edge is the space relationship. Then, a model classification method based on functional and computational ability was used to organize calculation and analysis process models. Thus, a highly integrated and synergistic "data-knowledge-model" organization and management model was established. The proposed approach was applied in monitoring soil moisture in high-standard farmland in Shandong, which included 44 pan spatiotemporal objects, 2 object space relationship network models and 5 calculation and analysis process models. The results demonstrated its efficacy and feasibility in designing and implementing high-standard farmland intelligent automatic irrigation and drainage systems, thereby offered technical support for advancing theoretical research and expanding practical application in geographic scenarios.

This paper reviews the social background of "pole-axis system" theory and the "T-shaped" land development and economic layout framework in China, especially the objective conditions that the country cannot implement another "strategic shift" of national development priorities, and the academic contribution of economic geography serving to national strategic development, as well as some concepts, ideas, knowledge and methods to achieve this goal. According to the significance and the scholars' comments of this theory and model in national practice, this paper describes the growth course and academic responsibility of an economic geographer to inspire the academic community to uphold the rigorous attitude of seeking truth from facts to make greater contributions to the construction of socialism with Chinese characteristics in the new era.

Rural attraction is an important indicator of the functions of the rural regional system during flow situations. This theoretical topic in rural development has been discussed within multiple disciplines, but lacks systematic research. Nevertheless, it has become a cutting-edge theoretical research topic in the field of rural geography. Following the research progress and theoretical foundations of rural attraction, this paper constructs a theoretical framework for rural attraction from a geographical perspective, and explains five of its most important issues. (1) The research literature on rural attraction has shifted from fragmented elaborations on the qualities of attractive villages and the unidimensional analysis of rural attraction to the exploration of its concept, mechanism, and evaluation system in terms of urban-rural interactions. The theories underlying the rural regional system of human-environment interactions, gravity, population migration, and attraction property rights, can provide a theoretical foundation and inspiration for the research on rural attraction. (2) Focusing on scientific issues in rural attraction, such as "what is-how-why-how to", and moving toward the framework goal of "theoretical innovation, serving practice, and methodological guidance," a theoretical framework for rural attraction is constructed with the support of spatiotemporal considerations, a comprehensive theoretical paradigm, and the methods used in the field of rural geography. (3) Five important issues experienced during efforts to improve rural attraction were analyzed. First, we analyzed the conceptual connotations of rural attraction based on the background of rural regional systems and spatial interactions from the perspective of spatiotemporal processes. Second, we constructed a measurement framework for rural attraction based on these conceptual connotations and evaluation principles. Third, we identified the regional types and spatial structures of rural attraction from the perspectives of spatial correlations and scale transformation. Fourth, following the theories of human-regional system of human-environment relationship and scale transformation, we explored the mechanisms of rural attraction's endogenous development and exogenous embedding processes. Fifth, considering historical processes and spatial heterogeneity, we explored the pathways and policy insights for enhancing rural attraction. Overall, this research attempts to construct a "what is-how-why-how to" research framework for rural attraction based on a comprehensive "spatiotemporal human-environment" perspective. This study aims to deepen and expand the theoretical research on rural attraction, in addition to providing theoretical references and policy insights for the implementation of rural revitalization strategies in the construction of harmonious and beautiful rural areas.

Urbanization has always been a crucial area for development geography. Regional development strategies that align with urban characteristics and the scientific allocation of construction land indicators can effectively guide the high-quality coordinated development of urban agglomerations. However, the issue of whether urbanization matches the development strategy has always lacked an in-depth response in geography. Moreover, as the control over agricultural and ecological spaces becomes increasingly strict, the availability of construction land indicators is increasingly constrained. The allocation of construction land indicators is thus critical for the distribution of regional resources and the achievement of development goals of regional urban agglomeration. Based on the construction principles of development geography indicator system and the core-periphery theory, this study comprehensively considered the three subsystems of urbanization (population, economy, and land) and the spatial link intensity among cities to analyze the impacts of "siphon" and "radiation" effects on regional development, and assessed whether China's two major regional development strategies matched the comprehensive development characteristics of urban agglomerations. Based on this analysis, the quantitative allocation of construction land in the Beijing-Tianjin-Hebei (BTH) and Yangtze River Delta (YRD) urban agglomerations was completed. The results showed that the comprehensive level index of urban (CLU) in core cities (Beijing and Tianjin) and peripheral cities differed significantly, demonstrating a clear core-periphery structure. Along with urbanization, the "siphon" effect in BTH was gradually weakening. Beijing's urban primacy decreased and the growth rate of the CLU dropped from 53.89% to 18.37% over the first and last 5 years of this study period. In contrast, the "radiation" effect in the YRD remained more obvious, exhibiting a development pattern driven by multiple growth poles in various smaller regions. As urbanization progressed, the BTH indicated a trend of coordinated development, while the integration level of the YRD continued to strengthen. Compared to the government's top-down indicator allocation data, the results of the quantitative allocation of construction land reduced volatility and increased robustness. This study confirmed the scientific basis of the coordinated development of the BTH and the integrated regional development strategy of the YRD from the perspective of development geography. It also provides empirical support for research on the allocation of construction land.

Maps are the language of geography and visual variables serve as fundamental theories in the fields of cartography. However, current research on visual variables in cartography predominantly relies on empirical description and induction, and the explanation of visual mechanism is insufficient. There are still three fundamental issues: the perceptual sequence of the visual variables is unclear, the granularity of the "shape" visual variable division is not precise, and the definition of the "location" visual variable is unclear. Based on the summary of the main visual neurons in the eye-brain system, this paper analyzes the neural mechanisms of visual variables in detail. The study uncovers several key findings: (1) The perception sequence of visual variables follows a pattern, starting with value and color, followed by simple location, orientation, size, and finally complex shape and texture. Eye-tracking experiments conducted on tourist maps show that using the feature that color can be perceived first, color can be used as a visual cue to strengthen the visual hierarchy of the map and guide the visual attention of the readers. (2) Curvature can be used as a subdivision variable of shape visual variable. The case study in the context of sustainable development mapping shows that curvature variables can be effectively used to express both qualitative and quantitative information. (3) Location can be directly and efficiently processed and recognized by visual neurons, and thus it should be defined as a visual variable. However, it should not be changed when the accuracy of graphic position is emphasized. Comparative experiments between navigation map and city image map show that the location variable can cause significant evoke differences in visual perception and emotional arousal. The research in this paper contributes to a deeper understanding of the theory of visual variables and provides new visual design theory for sustainable development mapping, creative and personalized mapping.

Global protected areas have been widely recognized for their conservation effectiveness, but are still facing problems such as insufficient coverage, ecosystem representation and species protected progress. At the same time, most of the protected areas are small, poorly connected and threatened by climate change and human activities. This highlights the urgent need to systematically improve the stability and conservation effectiveness of protected areas through the expansion and connectivity management of protected areas. Although some studies have tried to realize the connectivity of protected areas through ecological corridors, a unified concept has not been proposed, and a general consensus of the construction and optimization framework is lacking. Through a systematic review of relevant studies, the definition and classification system of protected area connectivity network, as well as the construction and optimization framework are put forward. According to the conservation objectives, protected area connectivity network can be divided into three categories, namely biological migration network, structural stability network and climate connectivity network. Different methods can be used to construct and optimize protected area connectivity network according to the framework of "expansion and optimization of protected areas - construction of landscape resistance surface-extraction of ecological corridors-connectivity network optimization". Current research focuses on constructing short-term effective network from a static perspective, emphasizing direct ecological benefits while ignoring conservation input and social value. In future research, dynamic connectivity network should be constructed from a dynamic perspective based on long time series data. The long-term effectiveness of the connectivity network should be safeguarded against the future threats of land use change and climate change. The optimal scheme of connectivity network construction and optimization should be determined based on cost-benefit analysis, considering the trade-off of different conservation objectives and social development. Finally, the social added value of the connectivity network should be enhanced to gain more support.

Selection of appropriate geographic boundaries for zoning the study area or images can effectively improve the accuracy and efficiency of land cover classification by reducing the complexity of land cover within the regions and the variability of its features in the images. At present, the regionalization data used in land cover mapping based on stratified classification strategies, such as ecological regionalization, lack targeted objectives, which limits its applicability and effectiveness in remote sensing classification. Vegetation phenology is the main cause of spectral heterogeneity within the land cover of natural scenes. To address this issue, this study proposed a remotely-sensed phenology pattern regionalization scheme for land cover classification of natural scenes. The regionalization scheme is implemented by constructing a zoning index system using vegetation indices, which reflect the greenness status of vegetation, and key phenological periods, which reflect the growth and development rhythm of vegetation. Small geomorphic regions are used as the zoning units, and a data-driven spatially constrained hierarchical clustering algorithm is employed in the regionalization. The evaluation results based on statistical tests and multi-source land cover products indicate that the remotely-sensed phenology pattern regionalization in this study effectively reduces the complexity of land cover within the region and the intra-class feature heterogeneity caused by vegetation phenology, and shows high potential in constructing representative land cover sample libraries and implementing stratified classification strategies.

During the Republic of China (1912-1949), Zhongshan Roads rapidly emerged in major cities and towns across the country, and hundreds of them remain today, primarily in affluent areas. To investigate this uncommon road-naming phenomenon, a comprehensive study was conducted on their construction process and spatio-temporal characteristics (within the scope of county-level and above administrative regions), using toponymy, historical geography, and GIS. Historical documents and maps were re-examined, combined with data from the China National Geographical Name Information Database, OpenStreetMap, and Historical GIS techniques such as spatial measurement, spatial analysis, and visualization. The results showed that: (1) Zhongshan Roads were initially named to commemorate Dr. Sun Yat-sen. During the Republic of China era, 599 Zhongshan Roads were established, primarily in Taiwan, Henan, Shaanxi, and along the southeast coast. (2) Today, there are 653 Zhongshan Roads, except in Xizang, Hong Kong, and Macao. (3) Among these, the Zhongshan Highway in Taiwan is the longest, while Zhongshan Street in Emei township, Hsinchu county, is the shortest. Tainan has the largest number of Zhongshan Roads overall, whereas Shanghai's Huangpu district has the highest concentration and density of these roads across China. (4) Spatial analysis revealed that historically, Zhongshan Roads were mostly found in the centers of old cities and towns. However, since the founding of the People's Republic of China in 1949, new Zhongshan Roads have gradually moved away from city centers. (5) Over the past century, there have been four significant periods of road-naming popularity: following Dr. Sun Yat-sen's passing, commemorating the Victory of the Anti-Japanese War and the recovery of lost territories, restoring place names altered during the 1966-1976 period in the 1980s, and naming new roads at the start of the 21st century. Zhongshan Road, with its century-old tradition, symbolizes the collective remembrance of Dr. Sun Yat-sen and his enduring legacy among the Chinese people. It also reflects China's pursuit of modernization and national rejuvenation in modern times. The data analysis in this paper may require partial refinement as more historical materials are unearthed and quantitative methods are updated, but it does not affect the overall conclusions.

Permafrost is highly sensitive to global changes, and it is important to reveal climate and environmental changes in permafrost regions using vegetation succession. Based on palynological evidence and AMS¹⁴C dating from a sediment core, vegetation succession and climate history in the Late Pleistocene of the Mohe Basin (MHB) in the Greater Hinggan Mountain permafrost region was reconstructed. The response of vegetation to environmental changes was further investigated. Results showed that pollen assemblages effectively reflect the vegetation composition in the MHB and surrounding mountainous areas. Based on the relationship between key regional vegetation and climate indicators, vegetation has undergone significant historical changes: from 30.0 to 27.1 ka BP, a meadow wetland landscape showed a cold and humid climate; from 27.1 to 20.5 ka BP, a coniferous forest-grassland landscape indicated a relatively cold and arid climate; from 20.5 to 11.3 ka BP, there was a transition from coniferous forest wetlands to mixed coniferous-broadleaved forest wetlands, indicating the beginning of a warming although the climate remained cold and humid; from 11.3 to 1.9 ka BP, a mixed coniferous-broadleaved forest wetland landscape demonstrated a warm and humid climate; from 1.9 ka BP to the present, a coniferous forest wetland landscape revealed a cool and humid climate. A comparative analysis showed that factors influencing vegetation succession include not only climate conditions related to latitude and land-sea location but also regional factors caused by permafrost itself. Vegetation succession exhibited different response mechanisms to permafrost changes during glacial and interglacial periods. During the Last Glacial Maximum, permafrost expansion benefited the growth of cold and drought-resistant terrestrial herbs with shallow roots such as Artemisia and Chenopodiaceae, leading to the expansion of arid grasslands. During the Holocene Megathermal Period, permafrost degradation provided favorable habitats for vegetation, and also facilitated the formation and expansion of wetlands, promoting the extensive proliferation of aquatic plants, ferns, mosses, and trees, forming a forest wetland landscape. Therefore, permafrost presence enhances the effects of water and heat under different climate conditions on vegetation, making vegetation more sensitive to environmental changes in permafrost regions.

Based on the diverse nexus between humans and nature, exploring innovative pathways and regional models for rural revitalization stands as a strategic cornerstone and a cutting-edge focus within rural studies. Following a systematical review on the shift of rural development paradigms, we in this paper propose an innovative pathway of rural neo-endogenous development driven by knowledge through the integration of concepts such as social innovation and rural transformation. Essentially, "knowledge-driven" can be understood as a process-based innovation, wherein various stakeholders participate in the generation, dissemination, feedback, and regeneration of scientific knowledge and local wisdom. This process ultimately precipitates shifts in behaviors and attitudes of both local and extra-local actors, thereby giving rise to collective insights and solutions for rural development. Regarding the functioning mechanisms, "knowledge-driven" typically facilitates the iteration of technological paths for rural development via four interconnected means: constructing novel discourses for rural transformation, empowering local communities, forging connections between local and extra-localities, and innovating rural governance. In practice implementation, "knowledge-driven" engages multiple stakeholders and unfolds across three sequential stages, they are, knowledge/experimentation searching, diffusion and expression of interest, collective learning and co-ordination. In conclusion, we contend that transcending the urban-centric "core-periphery" mindset, broadening the initial impetus and the cohort of pioneer actors, and streamlining the channel from "niche innovation" to "collective learning" hold significant promise for expediting the comprehensive revitalization of rural areas.

As China progresses in its high-quality development and new urbanization, the spatial development pattern of large cities is evolving from expansion of scale to optimization of existing stock. The polycentric system is widely utilized in guiding the macro-structure of spatial planning, playing a critical role in transforming urban development strategies, increasing urban efficiency, alleviating "urban diseases" and promoting urban renewal. This study establishes a framework for analyzing spatial performance in urban polycentric systems. With Hangzhou as the focal example, the evaluation proceeds across four dimensions of spatial performance, examining the city's internal spatial organization and the mechanisms of its formation. The results indicate that: (1) The polarization effect of the main center outweighs its diffusion, leading to a development pattern characterized by "strong primary and secondary centers, weak tertiary centers; concentration in the old cities, dispersion in the outskirts, differentiation of tertiary centers", with distinct disparities in the effectiveness of planning guidance; (2) Centers in the urban core and principal development directions generally exhibit high performance, with spatial forms moving towards "integration" or "central dissolution"; (3) Activity density performance maintains a balanced state at lower levels, with centers in tertiary areas and primary development trajectories achieving greater equilibrium; (4) Industrial upgrading and the construction of significant facilities drive the functional differentiation of the polycentricity, displaying patterns of horizontal and vertical divisions among center functions; (5) Travel efficiency performance aligns with the polycentric configuration, incrementally revealing the balanced nature of employment distribution across centers; (6) The evolution of the center system is shaped by a confluence of historical path dependence, natural geographic characteristics, economic and industrial development, advances in social demand, and government policy directives, especially those driven by government administrative efforts including development strategies, spatial planning, resource distribution policies, and major events, all of which have a pronounced guidance effect. Future initiatives should concentrate on the cooperative division of functions within the polycentric system, adapting spaces to meet the specific needs of different industries related to spatial and transaction costs, thereby forming both comprehensive and specialized centers. Utilizing major events and infrastructure-driven mechanisms should elevate the energy levels of centers. Moreover, the needs of micro-entities should be addressed by capitalizing on the economic effects of aggregation and market mechanisms to facilitate the orderly emergence and growth of autonomously formed centers. Strategic allocation of crucial resources through government administrative capabilities and policy instruments is essential to boost the development potential of peripheral secondary and tertiary centers.

The low-carbon transformation of the energy system has emerged as a key strategy for addressing climate change risks, promoting high-quality development, and ensuring energy security. However, the clean transformation of the energy system faces significant uncertainties and challenges due to the complex constraints of multiple goals. This paper provides a comprehensive review and integrated analysis of the basic concepts, research methods, and challenges associated with energy transformation, drawing the following conclusions: (1) Shifting focus of energy transition: The energy transition in the context of carbon neutrality has evolved from being primarily technology-driven to problem-driven. The pace and success of energy transitions vary greatly across regions and nations, with policy regulation, technological innovation, market mechanisms, and behavioral factors playing pivotal roles in driving change. (2) Quantitative research on energy transition primarily centers on assessing the extent of the transition and forecasting its future trajectory. However, due to the intricate interconnections and mutual influences among multiple systems, including energy, economy, environment, and society, the predictive simulations often exhibit a pronounced "black box" effect, making interpretation and transparency more challenging. (3) Controversies and future research directions: There is ongoing debate within the international community regarding the comprehensive effects of energy transformation. The development model and pathways that balance low-carbon goals, economic growth, and energy supply security still require further theoretical and empirical exploration. While significant attention has been paid to the environmental, economic, and safety benefits of energy transformation, the social impacts have received less focus, which may undermine the long-term sustainability of the transition. Future research should integrate the dual objectives of climate change mitigation and economic development, adopt diversified transformation strategies, emphasize supply-demand coordination, and promote regionally coordinated transitions. Furthermore, strengthening multi-scale, cross-sectoral analyses will enhance the effectiveness and sustainability of energy transformations. This research aims to deepen understanding of the epistemology and methodology surrounding energy transformation, offering geographical scholars new perspectives and avenues for further investigation into this critical area of study.

The Three-River-Source National Park, located in the hinterland of the Qinghai-Tibet Plateau, possesses unique climate and abundant genetic species. However, this region is facing serious ecological problems due to climate change and human activities. Accurate monitoring of spatiotemporal variations in net primary productivity (NPP) in the Three-River-Source region is crucial for promoting ecological conservation and environment improvement. Model simulation is an important approach in terrestrial ecosystem research, but it inherently remains uncertain. Multi-model integration techniques can enhance the accuracy of NPP simulation and provide a better estimation of NPP variations for environmental governance. In this study, we used four process-based ecosystem models (i.e., CLM, DALEC, CEVSA, and GLOPEM-CEVSA) and a multi-model integration analysis method to examine the spatiotemporal changes in NPP in the Three-River-Source National Park from 2000 to 2018 and to investigate the effect of climatic factors on NPP variations. The results show that NPP exhibited a decreasing trend from southeast to northwest, with an average annual NPP of 251.17 gC m^-2 a^-1 during 2000-2018. Ecosystems in the Lancang River Source Park had the highest NPP (267.24 gC m^-2 a^-1), followed by the Yellow River Source Park (198.81 gC m^-2 a^-1) and Yangtze River Source Park (121.88 gC m^-2 a^-1. The average NPP in the Three-River-Source region ranged from 222.00 to 298.02 gC m^-2 a^-1 and had a significant increasing trend with the rate of 9.8 gC m^-2 10a^-1. The attributions of NPP variation to climatic factors were far different among regions. It was primarily affected by temperature and radiation in the Yangtze River Source Park and Yellow River Source Park, but was also significantly influenced by precipitation in the Lancang River Source Park. The findings of this study could provide technical support and decision-making basis for assessing the effectiveness of ecological conservation and ecological management in the Three-River-Source National Park.

The relocation of urban administrative centers plays a crucial role in optimizing urban spatial structure and advancing the modernization of the national governance system and capabilities. A thorough analysis of the spatiotemporal patterns, driving mechanisms, and development trends of administrative center relocations in China is not only a practical necessity for supporting the modernization of national governance but also a foundational requirement for the standardization and scientific advancement of administrative center relocations. This study utilizes spatial analysis methods to comprehensively examine the relocation of administrative centers in cities at or above the prefecture level in China from 1978 to 2022. The results show that there have been 81 instances of administrative center relocations across the country since the implementation of the reform and opening-up policy in the late 1970s. These relocations peaked between 2003 and 2007 and showed significant regional disparities. These relocations are predominantly short-distance and mainly aimed at promoting the development of new urban districts, often resulting in a separation from the geographical center. The relocation of urban administrative centers is a complex process influenced by an interplay of multiple factors, including national policies, governmental guidance, power distribution, resource reallocation, and planning adjustments. The regulatory role of national policies and the guidance provided by city governments are critical components in this multidimensional negotiation. In the context of the current strict national regulation of administrative division adjustment, the relocation of urban administrative centers will continue to reinforce traditional driving factors while aligning with socio-economic and technological shifts, presenting new directions driven by ecological governance, transportation development, and the evolution of innovative industries. In the future, it is essential to carefully evaluate the necessity of relocation while maintaining the fundamental stability of administrative centers. Implementing top-level design for administrative center relocations, adhering to standardized approval processes, and rigorously evaluating the rationale are key to promoting all-encompassing urban advancement. This study provides a reference for scientifically understanding the patterns and intrinsic mechanisms of urban administrative center relocation.

The northern part of the Kumtagh Desert exhibits a dark surface color, ranging from brown black to grayish brown. Additionally, certain feather-like dunes often display contrasting patches of light and dark hues on their surfaces, which has emerged as one of the distinctive characteristics defining this desert. The origin of light and dark spots in sand grains was investigated by conducting field surveys from 45 geomorphic sampling sites in the northern Kumtagh Desertin late September to early October 2020 and 2021,75 groups of grain size analysis, 39 groups of color grains (434 grain size samples) were identified visually, as well as 157 samples of sediment chroma were determined by colorimeter. The findings demonstrate a robust linear relationship between the visual colorimetric index (CI) and the measured luminance L^* as well as yellowness b^*, indicating their interchangeability in expressing both color and brightness levels of sediment. CI and L^* exhibit close associations with particle color and size. The presence of black, gray, and brown hues can be attributed to the primary lithology of clasts and weathered attachments show a strong correlation with coarse rock debris, resulting in high chromaticity but low brightness. On the other hand, yellow and white tones primarily originate from light-colored rocks and minerals that are closely linked to fine particle sizes, leading to low chroma yet high brightness. The desert has obvious sedimentary stratification, in which parallel bedding is characterized by the largest particle size at the top and gradually decreasing downward, and has a major influence on the chromaticity of the dune surface. The variation in surface chroma of sand dunes is the outcome of peristaltic accumulation of coarse-grained rock debris and wind erosion transport of fine-grained minerals during the movement of sand particles. A slight relative change, ranging from 5% to 10%, in very coarse sand with high chroma -1.0~0 Φ or a mixture of very coarse sand and coarse sand -1.0~0.5 Φ can result in different shades of color spots appearing on adjacent areas of the dune surface. The present study can offer experimental models and data references to elucidate the origin and formation mechanism of surface color in sand dunes within the Kumtagh Desert and similar desert environments.

The optimal allocation and scientific management of rural logistics resources is the key to unblock the domestic transportation cycle, and it is also the focus of the construction of a powerful transportation country and the integration of urban and rural transportation. From two perspectives of driving and walking, this study constructs a research framework for the evaluation of rural logistics terminal distribution with accessibility and equity. This study analyzes the accessibility of 440000 administrative villages in China and their nearest rural logistics terminal facilities. By using the online map tool, this study reveals the spatial distribution pattern and regional differences of rural logistics terminal facilities, and evaluates the spatial equity of rural logistics terminal facilities at the county level with Lorenz curves and Gini coefficients. The results show that: (1) Accessibility of rural logistics terminal facilities presents significant regional difference, and it declines from the coast to the interior, which is consistent with the socio-economic development pattern in China. (2) Accessibility of logistics terminal facilities presents significant urban-rural differences. According to the comparative analysis of travel distance, travel time, and travel modes, the urban-rural differences have been widened on travel time and by walking. (3) Based on the analysis with rural population distribution, the distribution of rural logistics terminal facilities presents the transport-related exclusion. The above findings can provide scientific support for the scientific layout of rural logistics terminal facilities so that we could promote the people-oriented integrated development of urban and rural transportation, and assist rural revitalization, so as to achieve common prosperity.

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.

The integration of large-scale Low Earth Orbit satellite constellations (hereinafter referred to as "LEO constellations") and artificial intelligence (AI) technology presents a historic opportunity for a paradigm shift in geography research, heralding a new era for geography to evolve from qualitative geography, quantitative geography, and digital geography into the "LEO constellation-AI-driven Geography". Under this framework, future geographic research can rely on the high spatio-temporal resolution monitoring data provided by LEO constellations to accurately capture the high-frequency dynamic changes of geographic elements at multiple scales, particularly at the global scale. By coupling physical models with AI, it becomes feasible to conduct simulation experiments on the complex interactions between natural and human elements, system states, and interface changes. This will facilitate a deeper understanding of core geographic issues such as variable coupling, multi-process cascading effects, and teleconnection mechanisms. To propel "LEO constellation-AI-driven Geography", there is an urgent need to establish a new-generation data acquisition and sharing platform relying on LEO constellation, seamlessly creating a "dynamic map" of global geographic resources and elements. Additionally, a geographic process simulator that couples physical models and AI needs to be developed to intelligently simulate and predict changes and impacts of geographic elements and landscapes.