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  • "Pole-Axis System" Theory: Review and Practice
    LU Yuqi
    Acta Geographica Sinica. 2024, 79(12): 3015-3029. https://doi.org/10.11821/dlxb202412006

    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.

  • "Pole-Axis System" Theory: Review and Practice
    HE Canfei, SHENG Hantian, DAI Xiaomian
    Acta Geographica Sinica. 2024, 79(12): 2972-2990. https://doi.org/10.11821/dlxb202412003

    In the past 40 years since the theory of "pole-axis system" was put forward, its connotation has been continuously enriched, which has profoundly influenced the theoretical and empirical research in multiple disciplines. The theory has also greatly contributed to China's spatial development of national territory, planning and construction of urban system, and layout of major productive forces. In the new era, China's major regional strategies have profound scientific connotations, yet they still need to overcome blockages such as loose connections within and between urban agglomerations in the course of practice. In this sense, the framework of multi-dimensional proximity from the perspective of evolutionary economic geography can be instructive, since it further focuses on the dimensional linkages of cognitive proximity, technological proximity, relational proximity, and social proximity. Thus, in the context of "dual circulation" strategy, China's territorial space development should be further guided by the theory of "pole-axis system" as well as the framework of multi-dimensional proximity, accelerating the cultivation of new quality productivity, constructing a resilient network of inter-regional industrial collaboration, and comprehensively empowering regional high-quality development.

  • "Pole-Axis System" Theory: Review and Practice
    LU Dadao
    Acta Geographica Sinica. 2024, 79(12): 2951-2960. https://doi.org/10.11821/dlxb202412001

    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.

  • Regional Development Strategy
    SUN Jiuwen, JIANG Zhi, HU Junyan
    Acta Geographica Sinica. 2024, 79(12): 3110-3128. https://doi.org/10.11821/dlxb202412012

    High-quality development of the marine economy is a key task for accelerating the construction of a maritime power, so as to realize Chinese-style modernization. This paper defines the scientific connotation of marine economy and its high-quality development. Based on the three major systems of marine economy and the five new development concepts, this paper synthesizes the high-quality development index of marine economy by means of vertical and horizontal separation grade method and fixed-base efficiency coefficient method. Then, with the help of the method of Dagum Gini coefficient, Markov matrix, standard deviation ellipse and geographic detector, spatio-temporal evolution and driving factors of high-quality development in coastal areas are systematically discussed. The results show that: (1) The continuous improvement of the comprehensive level of high-quality marine economic development is due to the collaborative optimization of marine economic, social and environmental systems. Guangdong, Shandong, Shanghai, Jiangsu and Zhejiang are key regions leading the improvement of marine economic quality and efficiency. (2) The quality of marine economic development has obvious spatial and temporal differences. To be specific, there is a large gap within the southern blue economic circle, and the gap between the northern and eastern blue economic circles is also the most prominent. (3) The high-quality development of marine economy is moving forward in twists and turns. In terms of time, most provinces have the power to advance to a higher level, but the difficulty of transition is gradually increasing; In terms of space, the center of gravity of the marine economy's geographical pattern is always located in the Yangtze River Delta, forming a steady-state spatial structure of "one core and two wings". (4) The optimization of the quality of marine economy is the result of the joint action of the new development concept. After the introduction of the strategy of maritime power, innovation empowerment has replaced opening-up as the first driving force. In order to steadily promote the high-quality development of the marine economy at a higher level, it is necessary to implement the new development concept, which include give full play to the leading role of the blue economic zone, enhance the core competitiveness of the marine industry, build a free trade port with high standards, promote the cause of revitalizing the sea through science and education to cultivate new quality productive forces, deepen the construction of marine ecological civilization as well as clarify the key tasks of coastal areas. In this way, the sound operation of the marine economic, social and environmental systems tend to be promoted, completing the glorious mission of transforming to a maritime power.

  • "Pole-Axis System" Theory: Review and Practice
    CAO Weidong, CAO Ji, ZHANG Wenrui, YUE Wenbo, CAO Yuhong
    Acta Geographica Sinica. 2024, 79(12): 3030-3049. https://doi.org/10.11821/dlxb202412007

    Major productive forces are crucial to the country's long-term stability and sustained prosperity, and are also a powerful means of improving economic efficiency, promoting coordinated regional development, and strengthening international competitiveness. This paper summarizes the layout of China's major productive forces and their spatial patterns in different periods by collecting multi-source data such as historical documents, regional socio-economic statistical data and remote sensing of light, and borrowing technical methods such as MCR model, kernel density analysis and standard deviation ellipse, etc. The main conclusions are as follows: (1) The layout of China's major productive forces follows the law of economic geography agglomeration and diffusion cycle evolution, and has experienced the evolution of balanced development - decentralised development - centralised development - coordinated development-high-quality complementary development. This is manifested in the concentration of 156 projects to a few geographic spaces in the western region of China, dispersion in the central and western regions during the Third Front Movement, concentration along the eastern coast, and a gradient advancement toward the inland. However, the focus of development has always been in the southeast region along the Hu Huanyong line. (2) The results of the spatial pattern simulation of major productive forces follow the theory of regional development stages. During China's high-level development process, different spatial patterns have emerged successively: points (core poles), point-axis, and point-axis system (network), forming a multi-level pole-axis system with a "T" main framework along the coast and the Yangtze River, supplemented by other central cities and transportation arteries, in order to promote the balanced development of territorial space. (3) The main influencing factors of the development layout of China's major productive forces vary from time to time, with the geo-environment influencing the spatial layout in the early stage, and then the combined force of national strategies, policies and markets; GTWR further reveals that there is significant spatial and temporal heterogeneity in the factors influencing the development layout. The GTWR further reveals that there is significant spatial and temporal heterogeneity in the factors affecting its development layout. This study focuses on the layout and spatial patterns of the major productive forces, which can provide practical references for optimizing the layout of major productive forces and constructing a regional economic layout and national spatial system with complementary advantages and high-quality development.

  • "Pole-Axis System" Theory: Review and Practice
    LIU Yungang, LIU Xuanyu, WANG Yuqu
    Acta Geographica Sinica. 2024, 79(12): 3050-3062. https://doi.org/10.11821/dlxb202412008

    Owing to the long-standing land-sea division, the regional development theory represented by the pole-axis system has conducted insufficient research on the development potential of the land-sea transition zone and even the marine space. In this context, this paper re-explores the marine orientation of the "pole-axis system" theory and investigates the application of the pole-axis system beyond the land-based thinking. Specifically, taking the currently highly-regarded development of the Hainan Free Trade Port (HFTP) as an example, it commences from the general laws of island economies, traces the geographical relationships and development history of Hainan Island, and based on the expansion of the "pole-axis system" theory, deliberates on the development direction and ideas of the HFTP. This paper emphasizes that: (1) The spatial metaphor of isolation and connectivity of islands within the context of the pole-axis system are mutually reinforcing and compatible, and the cultivation and development of the pole-axis system of the HFTP need to take into account the synergetic effects of the island's geographical relationships at different spatial scales, namely the global, national, regional, and local levels. (2) The pole-axis system of HFTP highlights the role of "flow" rather than geographical proximity in the growth of islands and island clusters. The focus on island-island relationships needs to shift from centrality to the exploration of node attributes, while the focus on land-island relationships needs to change from hierarchy to functional complementarity. (3) The HFTP needs to establish an economic and industrial composite pole-axis system that integrates land, island, and sea, and deepen the intrinsic driving force for the coordinated development of different geographic units through the bidirectional interaction of "defining development based on the sea" and "leaning on the land towards the sea". This study hopes to contribute to enriching and enhancing the marine orientation of the "pole-axis system" theory and deepening the study of islands, including the HFTP, other island economies, and the entire island.

  • Regional Development Strategy
    YE Chao, LUO Shen
    Acta Geographica Sinica. 2024, 79(12): 3095-3109. https://doi.org/10.11821/dlxb202412011

    China is deeply interwoven with the world, which has an important impact on the economic geographical pattern of Chinese-style modernization. The economic geographical pattern of Chinese-style modernization is mainly configurated by three relations: relations between urban and rural areas, relations between the eastern and western regions, and relations between China and foreign countries. It is the foundation of the new journey of comprehensively building a modern socialist country. Using strategic-relational approach, this paper analyzes the characteristics of pattern evolution dialectically from the perspective of political party discourse and multi-scale spatial characteristics. After 1840, the capitalist world system disintegrated China's unified pattern, and the regional imbalance and rural-urban gap became prominent in China. At the beginning of the 20th century, the imbalance and gaps intensified in China amid the world's multipolar conflicts. The Communist Party of China created the path of the rural areas to encircle the cities and won the victory of the Chinese revolution, which also changed the world pattern. After 1949, under the Cold War, China began to embark on the path of independently building socialism with Chinese characteristics. The relations between urban and rural areas, between eastern and western regions, between China and foreign countries are shifting to balance. Since the reform and opening-up in the late 1970s, globalization and multi-polarization have propelled the transformation of Chinese-style modernization. The imbalance has shifted from worsening to easing, and China has quickly become an important pole in the world. The world is undergoing profound transformation unseen in a century, uneven development between urban and rural areas, between the eastern and western regions, between China and foreign countries is fraught with uncertainties. Coordinating the three relations is the key to the realization of Chinese-style modernization. China-world relations have a U-shaped cycle of 50 years, regional relations play an intermediary role, and rural-urban relations are the easiest to change. It is necessary to strengthen the research of the economic geographical pattern of modernization, and integrate the three relations into a new development pattern. The H-shaped pattern should integrate spatial development strategies and reshape an open oriented, inside-out pattern through institutional innovation and the empowerment of talent resources.

  • Talent and Education
    YAN Jiyao, ZHAO Yuan, TAN Wanli, XIONG Xiaoyan, ZHAO Lifen
    Acta Geographica Sinica. 2024, 79(12): 3197-3209. https://doi.org/10.11821/dlxb202412017

    Based on the data from childcare institutions released by the National Health Commission in June 2024, this study examines the spatial differentiation of childcare institutions across China using four provincial-level cities and 332 prefecture-level regions. The research employs ArcGIS spatial analysis methods and Geographically Weighted Regression (GWR) to uncover the influencing factors behind this spatial variation. Key findings include: (1) Childcare institutions in China predominantly exhibit a clustered distribution, characterized by a greater concentration in the east and sparser distribution in the west. This pattern manifests as "large clusters and small dispersions," with significant clusters forming in the Yangtze River Delta, Pearl River Delta, and Bohai Rim, and numerous monocentric clusters centered around provincial capitals and major cities. (2) The number of childcare institutions is positively correlated with the tier of the city. Cities with fewer childcare facilities are numerous and spread out, primarily located in the western and northeastern regions. In contrast, cities with a larger number of institutions are mainly situated in the eastern coastal areas and major central-western cities such as Chengdu, Chongqing, Hefei, and Zhengzhou. (3) The population of children aged 0-4 years plays a decisive role in the spatial distribution of childcare institutions. Per capita disposable income of urban residents, the labor participation rate, and average household size serve as auxiliary factors influencing this spatial variation. While the average household size generally has a negative influence, other factors positively affect the distribution. As city tiers decrease, the impact of these auxiliary factors lessens, with minimal influence on fifth-tier cities. In conclusion, the study offers targeted recommendations for the development of China's childcare services industry.

  • "Pole-Axis System" Theory: Review and Practice
    SUN Bindong, ZHENG Xiaohui
    Acta Geographica Sinica. 2024, 79(12): 2991-3006. https://doi.org/10.11821/dlxb202412004

    As the economic polarization has become increasingly prominent of China, underdeveloped regions urgently need radiation and driving forces. Simultaneously, with the notable trends of population return and decentralization, initial conditions have emerged for developing new growth points. China's territorial spatial governance faces new missions, necessitating the exploration of the contemporary value of the "pole-axis system" theory to guide the practice of coordinated regional development. Based on the essence of the "pole-axis system" theory, the central place theory, and the central flow theory, this paper proposes a polycentric and coordinated regional development model of large countries. Drawing upon the empirically verified effective radiation radius of first-tier central cities, this paper envisions establishing new first-tier central cities in the northwest and northeast regions, in addition to the existing four first-tier central cities of Beijing, Shanghai, Hong Kong (Shenzhen), and Chongqing. This endeavor aims to establish a multi-tiered system of central cities that relies on metropolitan areas, urban agglomerations, and urban networks to foster specialized division of labor and collaboration among regions, ultimately guiding balanced national development. As a novel application and extension of the "pole-axis system" theory, the polycentric coordinated development of large countries contributes to achieving the diverse goals of "efficiency-equity-security" in the territorial spatial system. Regarding the implementation path, territorial spatial planning should serve as the guiding force, with market mechanisms as the foundation, and the active intervention of a promising government as the support. This will reverse the imbalanced regional development patterns in China, realize regional coordinated development, and provide spatial support for enhancing China's overall competitiveness.

  • Climate Change and Surface Process
    HE Shanfeng, LI Zheng, FENG Aiqing, WANG Wei, MA Yunjia, WU Shaohong
    Acta Geographica Sinica. 2025, 80(1): 101-119. https://doi.org/10.11821/dlxb202501007

    Tropical cyclone activity has undergone significant changes under the impact of the global warming since the 20th century. However, the characteristic and trend changes of landing tropical cyclones over China still need to be further clarified. We conducted an analysis of the spatiotemporal characteristics and trends of landing tropical cyclones over China from 1949 to 2022 using the dataset of the best tracks of tropical cyclones from the China Meteorological Administration. Additionally, we explored the influences of El Niño-Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO) on landing tropical cyclone activities. The results indicate that: (1) The annual average number of landing tropical cyclones over China is approximately 8.85, showing a significant decreasing trend, and the decreasing range becomes larger with lower latitude overall. However, both the proportion of landing tropical cyclones to the total number and the percentage of higher intensity tropical cyclones increase. The landing tropical cyclones from July to September account for 76.3% of the total, in which August experiences the most. (2) The landing positions of tropical cyclones in China are mainly concentrated between 18°N and 26°N, accounting for approximately 88.2% of the total, and the landing frequency shows a sharp decline in the regions north of 30°N. The central landing position of tropical cyclones has shifted significantly northwestward, moving closer to China. Compared to 1949-1969, the central generating position from 2010 to 2022 shifted 4.5 degrees westward and 2.0 degrees northward. (3) There is a correlation between ENSO and the frequency variation of generating tropical cyclones in the Northwest Pacific and landing over China. El Niño promotes the formation of strong tropical cyclones and leads to a more southeastern bias in the generating positions of landing tropical cyclones, while La Niña has an opposite effect. The PDO also affects the tropical cyclones to a certain extent. During the warm phase of PDO, the generating position of tropical cyclones is westward and the number is less than that in the cold phase. This study further clarifies the changing trends and characteristics of the landing tropical cyclones over China since 1949. It also highlights the impacts of ENSO and PDO on tropical cyclone activities. The findings can serve as a scientific basis for conducting simulations and assessments of tropical cyclones and for disaster prevention and mitigation efforts.

  • Regional Development Strategy
    YANG Qingyuan, YAN Yan, BI Guohua, SU Kangchuan
    Acta Geographica Sinica. 2024, 79(12): 3129-3141. https://doi.org/10.11821/dlxb202412013

    Rural living space is the spatial area that accommodates the daily activities of rural residents. With the acceleration of new urbanization and rural modernization, and the comprehensive promotion of livable, business-friendly, and beautiful rural construction, the demand for rural space by diverse subjects such as original villagers, new villagers, and traveling villagers has shifted from "comprehensive spatial functionality" to "high-quality spatial functionality", presenting new theoretical requirements for the understanding of rural living space. To better serve the construction of livable, workable, beautiful and harmonious countryside, this paper proposes the concept of a "rural living space system". It clarifies the conceptual origins of the rural living space system from three perspectives: geographical understanding of space, the theory of "production of space", and the academic thought of "human-land relationship regional system". It deconstructs the connotations and extensions, elements and structures, functions and values, evolution trends, and risk predictions of the rural living space system. It is suggested that the research on the rural living space system should be carried out from four aspects: theoretical analysis, evolutionary drivers, operational mechanisms, and optimization regulation. Research on the rural living space system is an area that rural geography needs to focus on. Future research should concentrate on the relationships between elements, their evolution and drivers, and innovations in operational mechanisms. Empirical analysis of different types of rural areas should be conducted to establish a theoretical foundation for the optimization and reconstruction of the rural living space system in the construction of livable, workable, beautiful and harmonious countryside, providing case references to enhance the governance capacity and modernization level of the rural spatial governance system.

  • Hydrography and Water Resources
    LIU Hanqi, WANG Tingting, FENG Yao, WANG Hong, SUN Fubao, LIU Wenbin
    Acta Geographica Sinica. 2025, 80(1): 41-60. https://doi.org/10.11821/dlxb202501004

    Projecting changes in flow regime under climate change and reservoir operations is crucial for safeguarding water security, preserving biodiversity and restoring aquatic ecosystems of a basin. Leveraging bias-corrected climate model data, this study utilized the Soil and Water Assessment Tool (SWAT) with an improved reservoir module and Indicators of Hydrologic Alteration to project the impacts of climate change and reservoir operations on the flow regime of the Yangtze River basin in the 21st century. The results showed that: (1) The improved SWAT model outperformed the original version, enhancing the simulation accuracy of daily streamflow and hydrological indicators at representative stations. The NSE (Nash-Sutcliffe efficiency coefficient) and KGE (Kling-Gupta efficiency coefficient) of simulation and observation of daily streamflow increased by 0.01-0.26 and 0.01-0.08, respectively. (2) Climate change is projected to increase streamflow, in which the streamflow increases significantly from January to April (the maximum increase is 17%). Meanwhile, climate change increases the variability of pre-flood streamflow (the maximum increase is 18%), the frequency of extremely high pulse, the duration of extremely high pulse and the rise rate of flow. (3) Reservoir operations effectively replenish dry-season flows (the maximum increase is 67%), reduce the frequency of extremely high pulse (the maximum decrease is 16%), and shorten the duration of both extremely high pulse (by -10% to -4%) and extremely low pulse (by -51% to -38%). Reservoir operations improve the stability of flow. While upstream reservoir operations can partially counteract climate-induced streamflow changes, their regulatory capacity is constrained by operational rules and total storage capacity. Therefore, adjusting reservoir operation strategies in response to the impacts of climate change on streamflow becomes imperative.

  • Talent and Education
    HOU Chunguang, DU Debin, LIU Chengliang
    Acta Geographica Sinica. 2024, 79(12): 3142-3160. https://doi.org/10.11821/dlxb202412014

    The growth and cultivation of leading scientific talent has become a hot topic for the government and academia. However, previous research has focused on education and management issues in the process of talent growth, while the geographical factors and processes influencing talent growth have been overlooked and neglected. Based on the education and work resumes of Nobel laureates in science, this paper systematically deconstructs the geographical pathways, regional functions, and influencing factors involved in the growth of leading scientists from 1901 to 2022. The main conclusions can be drawn as follows: (1) The geographical pathways of the growth of leading scientists has a significant institutional community effect, and achieving scientific breakthroughs is highly dependent on a few research institutions. (2) In the education stage, the educational centers where leading scientists grow up exhibit a significant phenomenon of succession, showing a wide range of sources and the highly degree of aggregation of inflows. And the United States, Germany and the United Kingdom account for 78.3% of the volume of leading scientists mobility in the education stage. (3) In the work stage, the geographical pathways of the growth of leading scientists has further narrowed, and there is a clear geographical transfer in the scientific centers where leading scientists work. The United States has become the largest "magnet country", accounting for 53.7% of the volume of leading scientists mobility in this stage. (4) During the growth process of leading scientists, regional functions are divided into six types: birth, education, promotion, birth and education, education and promotion, and omnipotent. After World War II, only the United States has developed into omnipotent type. (5) The influence mechanism of the mobility of leading scientists has its generality and particularity. Language has been widely proven to play an important role in the cross-border flow of the general population, but its impact on the migration of leading scientists is not significant. The proximity of social systems, political environment, and higher education are important factors for leading scientists to consider in their migration. However, the scientific development level of destinations does not significantly affect the mobility of leading scientists in turbulent times.

  • "Pole-Axis System" Theory: Review and Practice
    LIANG Jinshe
    Acta Geographica Sinica. 2024, 79(12): 2961-2971. https://doi.org/10.11821/dlxb202412002

    The k = 4 system of the central place theory, growth pole and development axis, corridor or axis development, growth pole and growth center, poles and corridors development, and the small-scale development axis are typical development models with spatial significance. In this article, we compare them with the "pole-axis system" theory proposed by Chinese geographer, Lu Dadao, and investigate the similarities and differences in terms of core ideas, attentions and structures. It is shown that these six models have respectively discovered or concerned the various roles of industrial linkages or/and linear infrastructure in spatial economic development, focusing on spatial interaction mechanisms of some roles and also have spatial development propositions. Each of the six models may contribute to the studies on real striped economic system in some ways. However, the "pole-axis system" proposes the gradual diffusion of "pole-axis" and its hierarchical system generation mechanism, and integrates the generation mechanism of the "pole-axis system" with regional resources, environment, and development potential to determine the order of China's spatial development. It is the key feature that distinguishes the "pole-axis system" from the other aforementioned models.

  • Regional Development Strategy
    HUANG Xiankai, ZHANG Xiaoyuan, SHI Jinlian, ZHANG Xun, ZHENG Yaomin, WEI Yunjie, LIU Yu
    Acta Geographica Sinica. 2024, 79(12): 3080-3094. https://doi.org/10.11821/dlxb202412010

    To accurately grasp and effectively coordinate the strategic goals of the great rejuvenation of the Chinese nation and the unprecedented global transformations in a century, while enhancing the country's cultural soft power and the influence of Chinese culture, and promoting the construction of a new form of human civilization, the Chinese nation objectively needs to establish a strategic space that supports the inheritance and innovation of Chinese civilization. This strategic space will serve as a cultural landmark for realizing the great rejuvenation of the Chinese nation through Chinese-style modernization. To achieve this, we develop a construction index system for the strategic space of Chinese civilization inheritance and innovation by repeatedly examining China's regional development and historical and cultural territory. The index system comprehensively incorporates factors such as historical and cultural inheritance, rural revitalization, ethnic diversity, and ecological protection and diversity across five dimensions: history, geography, culture, society, and ecology. At the national district/county level, the strategic space for the Chinese civilization inheritance and innovation is divided into infrastructure construction area, key construction area, priority construction area, and core construction area based on the comprehensive evaluation results. The evaluation results reveal that the strategic space has formed a core area around Shaanxi and a southern core area around Guizhou. The construction conception of the strategic space for the Chinese civilization inheritance and innovation and its division provides strategic support for advancing the great rejuvenation of the Chinese nation and facilitating Chinese-style modernization. Additionally, it plays a significant role in preserving the Chinese spirit and promoting rural revitalization as well as coordinated urban-rural development.

  • "Pole-Axis System" Theory: Review and Practice
    CHEN Mingxing, CHENG Jiafan, SUN Dongqi
    Acta Geographica Sinica. 2024, 79(12): 3063-3079. https://doi.org/10.11821/dlxb202412009

    In 1984, Professor Lu Dadao first proposed the "pole-axis system" theory and the "T-shaped" spatial structure of China's territorial development and economic layout at the National Economic Geography and Land Planning Symposium. As a model of regional "optimal structure and optimal development", the theory has become one of the milestone research results in the development of human and economic geography in China after continuous improvement and deepening. By reviewing the development process of the "pole-axis system" theory and the "T-shaped" spatial structure, this paper reviews the quantitative characteristics, institutional distribution, published journals, research topics, and hot topic evolution of relevant research literature, and clarifies the characteristics and trends of research in relevant fields in the past 40 years. The findings are as follows: (1) The theory of "pole-axis system" and the "T-shaped" spatial structure have been receiving continuous attention from the academic community, with the number of studies showing a significant correlation with the release of national policies. (2) Key research institutions, such as the Institute of Geographic Sciences and Natural Resources Research at the Chinese Academy of Sciences, Nanjing Normal University, and Central China Normal University, serve as prominent representatives in this field. These institutions collectively cover all regions of China, which may be closely tied to empirical studies of the theories in various areas. (3) The research articles have been published in multidisciplinary journals, exerting a notable influence primarily in the fields of geography and economics. (4) The research themes, research areas and methods of the "pole-axis system" theory have been continuously expanded and enriched in the three stages of development. Then, based on policy analysis and representative evaluation, the research expounds the extensive application and profound influence of the "pole-axis system" theory and the "T-shaped" spatial structure in the fields of territorial spatial planning, regional development strategy and multi-scale regional planning. Furthermore, this paper probes into its application value in the fields of territorial spatial planning with multiple-plan coordination, regional coordinated development, new urbanization and urban-rural integrated development, as well as allocation of new quality productive forces and other major productive forces in the new era.

  • Talent and Education
    WANG Changsong, WANG Mingyang
    Acta Geographica Sinica. 2024, 79(12): 3161-3176. https://doi.org/10.11821/dlxb202412015

    Traveling has been a constant exploration of new knowledge and experiences in both the journey and the destination throughout the ages. Travelogues, in turn, are direct records of historical travel activities. During the Ming and Qing dynasties, with the improvement of canal transportation and canal systems, a comprehensive water-land transportation network centered around the Grand Canal (Beijing-Hangzhou Canal) and incorporating the north-south postal roads along the canal gradually took shape. This development attracted numerous officials, literati, envoys, and other elite groups, leading to the creation of a substantial number of travelogues and diaries related to the Grand Canal and its surrounding landscapes. Focusing on these travelogues, this study examines the spatiotemporal characteristics and influencing factors of the canal travels of elites in the Ming and Qing dynasties, contributing to a deeper understanding of the operation of transportation systems and the travel patterns of people in traditional societies during historical periods. This article, adopting a perspective of "mobility" and drawing on methods from historical geography, extracts information and expresses spatial characteristics from travelogue texts, revealing the overall spatiotemporal features of canal travels by Ming and Qing elites. Based on this, the study discusses the influences and constraints on individual travel activities. The research findings include: (1) Canal travels during the two dynasties formed concentrated zones, namely the Beijing-Tianjin travel belt in the north and the Huaiyang (Huai'an and Yangzhou)-Jiangnan travel belt in the south, while the central region remained relatively sparse. (2) Under the influence of natural conditions and canal transportation systems, travel activities exhibited a certain temporal rhythm within a year. (3) Factors such as social status, travel destinations, and modes of transportation significantly influenced the behavioral patterns, spatial perception, and emotional experiences of travelers during their journeys. Building on these analyses, this article proposes a mobility analysis framework for historical transportation geography, aiming to provide insights into the application of mobility paradigms in historical periods. This research not only contributes to the understanding of historical travels but also lays the groundwork for further exploration of mobility in historical contexts.

  • Hydrography and Surface Processes
    YU Guo'an, HOU Weipeng
    Acta Geographica Sinica. 2025, 80(3): 694-711. https://doi.org/10.11821/dlxb202503008

    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.

  • Theory and Methodology Exploration
    GUO Hao, DONG Lei, WU Lun, LIU Yu
    Acta Geographica Sinica. 2025, 80(3): 567-585. https://doi.org/10.11821/dlxb202503001

    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.

  • Frontier Theory and Methodology
    GE Quansheng, SUN Fubao, JIANG Dong, SU Fenzhen, LIAO Xiaoyong, YANG Linsheng, ZHU Huiyi, LIU Ronggao, LU Feng, XU Duanyang, ZHU Mengyao, CHEN Jiewei, YUAN Wen, TAO Zexing
    Acta Geographica Sinica. 2025, 80(1): 3-11. https://doi.org/10.11821/dlxb202501001

    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.

  • Climate Change and Surface Process
    SHEN Yanjun, MA Tianchi, PENG Jianbing, QIAN Hui, DUAN Fenghao, XU Panpan, CHEN Siwei, WANG Rui, NING Yibing, MU Qingyi, SHEN Wei, CHENG Yuxiang, SHI Bailei
    Acta Geographica Sinica. 2025, 80(1): 132-146. https://doi.org/10.11821/dlxb202501009

    The valley roads at the northern foothills of the Qinling Mountains deeply cut the main chain of the Qinling Mountains, and are the "natural window" to gain insight into the geology, geomorphology, ecology and hydrological evolution of the Mountains. In this paper, the spatial distribution pattern and development characteristics of the valley roads at the northern foothills of the Qinling Mountains (Shaanxi section) were obtained by using Google Earth remote sensing image data, DEM elevation data and water system vector data, combined with ArcGIS, GlobalMapper multimodal spatial data identification and interpretation. The inheritance relationship between the valley roads at the northern foothills of the Qinling Mountains and the Guanzhong river system was explored. The following understandings were obtained: (1) According to the geomorphological characteristics of the valley roads, the length, pedestrian and water channel, the statistical standard of the valley roads was put forward. Combined with contour terrain and digital elevation model, the zoning interpretation is carried out, and the actual number of valley roads is 206. (2) Based on the visibility of remote sensing interpretation and the endowment water system in the valley roads, 76 representative valley roads were selected for statistical analysis. According to the length (≥15 km, 5-15 km, <5 km), the large, medium and small valley roads were divided. The Xi'an section is the most densely developed mainly for medium valley road (44.74%). (3) The direction of the valley roads is mostly N0°-NE30°, approximately perpendicular to the strike of the Fenwei Fault. The elevation of Yukou is normally distributed, concentrated between 500-800 m. The spacing between the valley roads is the rhythmic distribution of "small valley roads in big valley roads". (4) The elevation of the middle line of the valley roads is mainly distributed at 600-1500 m, the slope is mainly concentrated at 0°-20°, the width of the valley entrances are mainly at 30-90 m, and the shape of the valley entrances are mainly U-shaped, V-shaped and inverted trapezoidal. (5) The valley roads at the northern foothills of the Qinling Mountains and Weihe water system have a close inheritance relationship. Six of the "Eight River Systems in Chang'an" originated from the northern foothills of the Qinling Mountains, characterized by multi-source confluence. The purpose of this study is to provide detailed background data for the study of the most iconic geological and geographical labels in the Qinling Mountains with valley roads.

  • Urban and Regional Development
    WANG Shengyun, PAN Liuxin, WANG Zhenbo
    Acta Geographica Sinica. 2025, 80(4): 1009-1030. https://doi.org/10.11821/dlxb202504010

    Narrowing the gap of regional economic development and maintaining the balanced development path is the indispensable goals of China's regional coordinated development. In this study, the nighttime light image data and GDP statistical data are integrated to construct the Genuine Economic Index (GEI). Based on GEI, the Theil index, scale variance model, and the spatial filtering model are combined to analyze the spatial and temporal evolution of China's regional economic discrepancy from a multi-scale perspective. The results show that: (1) China's absolute regional economic differences expanded year by year, while the relative regional economic differences tended to shrink overall from 2000 to 2020. (2) Under different regional divisions, the scale variance of China's regional economy is manifested as municipal scale > county scale > provincial scale > regional scale, with the largest increase and highest contribution rate on the municipal scale. Narrowing inter-municipal gap is the key to decrease China's regional economic differences. (3) The contribution rate of spatial autocorrelation increased from 23.804% to 26.079% during 2000-2020. Regardless of spatial autocorrelation factors will lead to an overestimation of China's regional economic differences. (4) The impact of spatial autocorrelation on regional economic differences is scale sensitive, the smaller the spatial scale is, the stronger the sensitivity is. After spatial filtering, inter-county economic differences have been the largest part of China's regional economic differences. (5) Human capital, industrial structure, consumption scale and fiscal decentralization have a significant positive impact on China's Genuine Economic Index, however these factors show an obvious regional heterogeneity. This study could provide a multi-scale, refined and differentiated reference for the implementation of China's regional coordinated development strategy.

  • Frontier Theory and Methodology
    ZHANG Hui, ZHU Wenquan, SHI Peijun, TANG Haiping, HE Bangke, LIU Ruoyang, YANG Xinyi, ZHAO Cenliang
    Acta Geographica Sinica. 2025, 80(1): 12-27. https://doi.org/10.11821/dlxb202501002

    Vegetation on the Qinghai-Xizang Plateau exhibits high-altitude and vertical zonation distribution characteristics, which pose significant challenges for fine-scale vegetation classification based on remote sensing. A major issue is the limited separability of remote sensing features among certain vegetation types, necessitating the effective integration of additional non-remote sensing features to improve separability. To address this problem, the present study developed a novel method for fine-scale vegetation remote sensing classification by progressively incorporating coarse spatial resolution vegetation and environmental features. This approach aims to improve both the accuracy and precision of classification. The new method comprises three primary components. First, vegetation and environmental features that substantially enhance vegetation classification and exhibit distinct feature differences are selected. These features are then used to calculate the prior probabilities for each class through a generalized additive model. Concurrently, machine learning classification with remote sensing features is employed to obtain the posterior probabilities for each class. Finally, by applying the Bayesian algorithm, the prior probabilities derived from coarse spatial resolution data are employed to adjust the posterior probabilities obtained from high spatial resolution data, resulting in refined classification outcomes. The method was rigorously tested and applied to the Qilian Mountains, Yellow River Source Area, and Hengduan Mountains on the Qinghai-Xizang Plateau. Sentinel-2 remote sensing data with a spatial resolution of 10 m, vegetation and environmental data with spatial resolutions ranging from 90 m to 10000 m, and ground survey data were utilized. The fine-scale vegetation classification results with a spatial resolution of 10 m were achieved. Compared to using only remote sensing features, the new method improved classification accuracy by 8% to 24%. This new classification method provides effective technical support for improving the accuracy and precision of vegetation classification and offers significant reference value for fine-scale vegetation classification on the Qinghai-Xizang Plateau and similar regions.

  • "Pole-Axis System" Theory: Review and Practice
    CAO Xiaoshu
    Acta Geographica Sinica. 2024, 79(12): 3007-3014. https://doi.org/10.11821/dlxb202412005

    In the context of Anthropocene, the human-nature system is the main body of the surface earth system, and it is the result of the long-term interaction between society and nature, as well as the evolution of the man-land relationship. The formation of the human-nature system on the earth's surface is an objective process of socio-economic spatial organization, with scientific spatial organization structure and form. While, the "pole-axis system" is a scientific refinement of how to optimize the development of various spatial structures and development types, which can not only represent the space in the time chain, but also serve as an important theoretical support for spatial inversion and spatial planning. It can also nest in different scales from community to the whole world, with the point as the location space and the axis as the flowing space, forming a modern human-nature coupling spatial system. As a geographical entity space, national land space is a place where nature and human beings practice together, which is systematic. It is vertically composed of a geological structure system, natural ecological system, infrastructure link system, and human-nature coupling system. Horizontally, it is a spatial pattern formed by units, zones, and divisions. Its connection is linked by the transportation of matter and energy. Therefore, the "pole-axis system" can be further extended to the theory of the territorial space system in epistemology and methodology, which includes the territorial space value, function, guarantee and security. Theoretically, it also supports the realization of territorial space value, territorial space security guarantee, territorial space evolution mechanism, and territorial space optimal regulation. The territorial space system is realized through the territorial space planning system, so as to realize the optimal system of territorial space governance, moving towards the harmonious coexistence of human and nature, along with the sustainable development of the community of human destiny.

  • Talent and Education
    XU Haidong, HUANG Xuliang, NI Pengfei
    Acta Geographica Sinica. 2024, 79(12): 3177-3196. https://doi.org/10.11821/dlxb202412016

    Shaping modern human resources and supporting Chinese modernization with high-quality population development is a necessary requirement for promoting high-quality economic development. This article analyzes the spatio-temporal pattern and evolution characteristics of China's total human capital development at the district and county levels, and constructs a bilateral stochastic frontier model to measure the bilateral impact and mechanism of urban core areas on county-level human capital. The research shows that: (1) From 2000 to 2020, China's county (city) human capital continuously increased, but the growth rate slowed down. (2) Overall, urban core areas had a significant driving effect on the improvement of county-level human capital, and the main paths were industrial spillovers and innovation spillovers. (3) The impact of urban core areas on county-level human capital changed from "siphon" to "spillover", raising the actual total human capital of the county from 0.137% below the frontier level in 2000 to 2.657% above the frontier level in 2020, and there was still room for growth in terms of temporal trend. (4) The impact of urban core areas on county-level human capital showed significant spatial differences. In 2020, the development of core areas in first-tier and second-tier cities resulted in 39.110% and 12.966% of county-level actual human capital higher than the frontier level, while the corresponding figure for fourth-tier cities was only 0.006%. (5) There is a significant negative correlation between the net effect of urban core areas on the improvement of county-level human capital and geographical and temporal distance, with the inflection point from positive to negative being around 100 kilometers and 100 minutes.

  • Theory and Methodology Exploration
    WANG Qiang, DANG Niu, JIANG Zilong, FAN Jie
    Acta Geographica Sinica. 2025, 80(3): 586-604. https://doi.org/10.11821/dlxb202503002

    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.

  • Hydrography and Water Resources
    WEI Mengdan, LIU Chengliang, LIANG Qiaoxia, KONG Weiming, HU Yaokun, WANG Xiaoming
    Acta Geographica Sinica. 2025, 80(1): 61-80. https://doi.org/10.11821/dlxb202501005

    Water provisioning in the Asian Water Tower (AWT) is crucial to meet the demand of economic development in basin countries, whereas both climate change and economic development are altering the balance of water supply and demand. Previous researches mostly focus on the problem of how the availability of upstream water resources affects downstream uses, but the benefits to economic development are yet addressed. On the basis of hydrological runoff data in the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP), we developed an index representing the degree of water stress mitigation by the AWT, and established a production-oriented model using Adaptive Regional Input-Output (ARIO), for the evaluation of economic benefit and its relationship with the degree of water stress mitigation. The results show that the water stress mitigation index of basin countries exhibits dependency on geographical location, and the Central Asian countries display as a core area with higher mitigation index and temporal variation. Meanwhile, the overall economic benefit of the AWT to mitigate water stress reaches as high as 13.06% of Gross Domestic Product (GDP) of all basin countries. The benefit exhibits a significant spatial heterogeneity, with the beneficiary countries mainly concentrated in Central and South Asia, exceeding up to 80% of GDP, such as Bhutan, Nepal, Tajikistan and Kyrgyzstan. Importantly, the benefit not only depends on the degree of water stress mitigation, but also on economic structure, notably demonstrated by Bangladesh. Furthermore, the marginal economic benefit of water stress mitigation by the AWT increases with the degree of mitigation. This implies that the reduced water supply will have a much greater impact on the countries highly benefited from the AWT, especially in the low developing countries. The disparity between countries that benefit the most and least, respectively, can reach up to 2.63 times. As mentioned above, the low developing countries receive the greatest economic benefits when there is an increasing water supply of the AWT. Therefore, the greater significance of AWT is illustrated by its role, not only in mitigating water stress, but also in advancing economic development in the basin countries. In this regard, the basin countries are suggested to take joint actions, so as to safeguard the AWT, and establish a long-term comprehensive water resources management that takes into account the balance of supply and demand. This study can provide evidences for promoting sustainable development of the economic circles around the AWT, especially in low developing countries.

  • Urban and Regional Development
    ZHANG Yaojun, CHEN Yun, WU Xiwei
    Acta Geographica Sinica. 2025, 80(2): 345-359. https://doi.org/10.11821/dlxb202502006

    Large cites play a leading role in the industrial transformation and upgrading. Based on data on municipal districts for 284 cities at the prefecture level and above in China from 2006 to 2019, this paper investigates the relationship between urban industrial transformation and population size of cities and its evolution pattern, under the perspective of urban scaling laws. There are two main findings in this study. Firstly, the development of urban industries in China is influenced by both the overall development of industries and the change in urban population size, and the correspondence between scaling exponent and location quotient for industries is confirmed: specifically, large cities, which are ranked in the top 5% in terms of population size, are characterized by industries with a superlinear scaling factor of employment population, such as real estate, rental and business services, and scientific research and technical services; small cities, which are ranked in the bottom 75% of population size, are typified by industries with a sublinear scaling factor of employment population, like agriculture, forestry, animal husbandry, fishery, and mining; and cities ranked from 5% to 25% of population size are observed to have an industrial structure which is in a transitional phase between the first two types of cities. Secondly, the evolution pattern of urban industries is verified by Chinese evidence, with average recapitulation index of 0.49 and 0.37 respectively for industries and cities. It is thus evident that the industrial structure in cities shifts gradiently with their population size, that is, industrial upgrading in large cities comes first, and then it will exert a radiating effect on the industrial transformation in small cities.

  • Climate Change and Surface Process
    ZHANG Ziyun, YANG Pingguo, ZHANG Peng, LI Xinxia, HE Kaiyang, AO Hong
    Acta Geographica Sinica. 2025, 80(1): 120-131. https://doi.org/10.11821/dlxb202501008

    The East Asian monsoon plays a crucial role in linking the climate systems of the Northern and Southern Hemispheres, affecting the lives of hundreds of millions of people. There, understanding the evolutionary traits from previous warm periods, such as the deep-sea oxygen isotope stage 5 (MIS 5, 130-70 ka BP), is crucial to comprehending the pattern of climate change in Asia and the mechanisms causing it. The MIS 5, with its lengthy duration and significant amplitude of climatic changes, is the warmer period closer to us and has been extensively utilized in studies of Late Pleistocene climate change. Here, we report new rock magnetic, environmental magnetic, and diffuse reflectance spectroscopy from the Huanxian loess-paleosol sequence from 155 to 20 ka BP, north-central Loess Plateau to study the relationship between monsoon precipitation and temperature changes during MIS 5. Rock magnetics results indicate that the magnetic minerals of the loess-paleosol sequence in Huanxian are dominated by pedogenic fine-grained magnetite/maghemite, with grain sizes ranging from superparamagnetic (SP)/single-domain (SD) to small pseudo-single domain (PSD) sizes (i.e., from <30 nm to ~1000 nm). The environmental magnetic and diffuse reflectance spectroscopy results indicated that the Loess Plateau had higher precipitation and temperature during MIS 5 than MIS 2-4, and MIS 6, suggesting a coupled relationship between them in the geologic period on the orbital (glacial-interglacial) time scale. During MIS 5, it is discovered that there was a decreasing trend in temperature but not in precipitation, indicating that the trend of precipitation and temperature in the north-central of Chinese Loess Plateau were decoupled. Our research demonstrates that temperature and precipitation in the study area have always had a coupling and decoupling relationship. Combining a detailed land-sea comparison, we suggest that both monsoon precipitation and temperature changes are influenced by ice volume and atmospheric CO2 concentration in the Northern Hemisphere. Additionally, monsoon precipitation is also influenced by the 20000-year variation in summer solar radiation.

  • Urban and Regional Development
    ZHANG Juntao, WU Yuyang, ZHU Yue
    Acta Geographica Sinica. 2025, 80(2): 396-414. https://doi.org/10.11821/dlxb202502009

    The collaborative agglomeration of manufacturing and producer services is a new industrial form and has become an important growth pole to achieve high-quality development of regional economy. Based on the perspective of complex spatial network, this paper first constructs an improved collaborative agglomeration index of manufacturing and producer services, and then adopts the revised gravity model to calculate the spatial correlation matrix. Secondly, social network analysis method is used to describe the structural characteristics of the spatial correlation network of industrial collaborative agglomeration in 31 provinces (autonomous regions and municipalities directly under the Central Government, excluding Hong Kong, Macao and Taiwan) in China from 2003 to 2021. Finally, this paper explores the driving mechanism of correlation network under the spatial interaction theory and resource field theory by combining regional geographical conditions and socio-economic factors. The results show that: (1) During the study period, the spatial directivity of the collaborative agglomeration between manufacturing and producer services has not changed, the regional differences tend to converge, and the unbalanced distribution pattern has been improved. (2) The collaborative agglomeration of manufacturing and producer services gradually presents a complex network form of multi-thread interweaving, the overall network density is constantly increasing, and the spatial correlation has a large room for improvement. The network connectivity is good, the stability of the network structure is continuously enhanced, and the "core-edge" structure in the individual network is prominent. (3) The eastern region is mainly the "net benefit" and "broker" blocks, the northeast region and the western region are the "two-way spillover" and "net spillover" blocks. The spatial correlation network is dominated by the spillover effect and correlation effect between blocks. (4) Spatial adjacency, differences in economic development level, differences in labor input level and other factors jointly drive the formation of spatial correlation network. The conclusion of this study is helpful to optimize the spatial correlation network of manufacturing and producer services and promote the realization of high-quality economic development and regional coordinated development.