Ladakh is located in the northwest of the Qinghai-Tibet Plateau, the western section of the Himalayas, and the upper reaches of the Indus River valley. It is now part of Indian-controlled Kashmir. Since ancient times, Ladakh has been the "key point" from northwest South Asia to the Ngari Prefecture of Xizang and southern Xinjiang. However, most existing research on Ladakh focuses on its local history and culture. Although there are some related works on geopolitical relations, few have studied the historical changes of this region and its subordinate relationship and geographical value with China over a long time scale and analyzed the geographical significance of Ladakh. At the same time, some erroneous views and geographical maps have been disseminated on the Internet at home and abroad, which urgently needs a comprehensive correction from the academic level. Based on a variety of historical documents, map data, and a detailed review of previous research results, this paper demonstrates the changes in place names, historical evolution, and regional scope of Ladakh from the 1st to the 21st century and analyzes its significance in the homeland security of western China. The results show that: (1) As the native land of China's Xizang Ladakh was part of the Tubo Dynasty until the 9th century. After the collapse of the Tubo Dynasty in the middle of the 9th century, Ladakh was an essential part of the Ngari local administration established by the descendants of the Tubo Royal family. In the 13th century, Ladakh was again united within the territory of China's Yuan Dynasty and continued through the Ming and Qing dynasties. It remained until the mid-19th century when the Prince-state of Jammu in southern Kashmir invaded it and incorporated it into the British Indian colony. It was then occupied by the Indian army in 1947. (2) Ladakh region has a tortuous history with many changes in place names. However, when Jammu annexed it in modern times, Ladakh only referred to the upper reaches of Indus Valley between the Western Himalayas and the Karakoram Mountains, with Leh as the center. (3) The complexity of the historical and geographical processes in the Ladakh region makes it the central area of conflicts created by India in the western section of the China-India border. Therefore, China should adopt active strategies to avoid India's continuous "assimilation" policy.

The land conversion processes concerning non-agricultural and non-grain production areas have prominently decreased arable land availability, which substantially impacted grain production capacity and threatened national food security. Thus, it is critical to establish a novel scientific approach to identify spatio-temporal evolution patterns of land conversion and its influencing factors in different stages. This study evaluates the evolutionary characteristics of non-agricultural and non-grain fields by constructing a comprehensive index system that considers factors like cultivated land resources, social and economic conditions, and farmers' subjective perspectives, using a county as the basic research unit. For a comprehensive analysis, a geographical detector model was utilized to quantify driving factors in different stages. The results indicated spatial clustering effects for non-agricultural and non-grain fields throughout China, particularly in the eastern region beyond the "Hu Huanyong Line". Further analysis revealed a spatial pattern for non-grain conversion phenomenon was more intense in the southwestern than the northeastern fields. Over the past four decades, non-agricultural fields recorded an area expansion, but the year-wise area increase was gradually reduced, while non-grain areas exhibited a "growth-stable" change pattern. Although progress in non-grain was less in primary producing areas over the last 40 years, an increase of 1.49 times and 1.33 times was recorded from 2010 to 2020 in PSB (production and sales balance area) and Mrt (marketing) areas, respectively. Compared to the period 1980-2000, the rate of non-agricultural conversion in primary producing areas decreased by 77% during 2010-2020, while the rate of non-agricultural conversion increased by 1.63 and 4.65 times for PSB and Mrt regions, respectively. Based on these findings, this paper puts forward suggestions, such as setting control rules and subsidy mechanisms according to area classification, promoting control policies based on regional considerations, strengthening dynamic monitoring and risk warning, as well as enhancing supervision and assessment.

Despite the initial development goals achieved, China's macro-economy is still deeply affected by the external environment and stuck in its own structure at the same time. In retrospect, not until 1949 with the founding of the People's Republic of China did China's budding regional economy witness the prominence of a fixed development pattern shifting from a spontaneous to an actuating one. After comparing the three regional economic practices, this paper finds that each development stage has its corresponding development strategy. At the same time, several development patterns, namely, the coastal and inland areas, the three regions, and four plates were formed accordingly. Furthermore, through combing the literature and historical facts, this paper determines the historical starting point, division criteria and division scheme of China's regional economic development before summarizing three main lines and also contradictions therein: the government-market relations against the background of market reform, the coastal-inland relations against the tide of economic zonation, and the urban-rural relations against the trend of urbanization. Based on the above, the paper constructs a three-dimensional model out of the spatio-termporal process of China's regional development before proposing new historical stages from the perspective of economic system modernization. These historical stages are: industrial economy, special zone economy, district economy, regional economy and urban network economy. Finally, from the urbanization angle, this paper concludes that for different urbanization stages, regional policies should be industrial policies, factor policies, fiscal and tax policies sequentially.

Deconstructing rural spatial characteristics is the precondition for building rural spatial governance system in the new era, and multi-scale rural spatial characteristics and its governance path would effectively support the modernization of the national governance system. Based on the comprehensive, regional and mobile thinking paradigm of geography, this paper deconstructs the multi-scale rural spatial characteristics, identifies its internal operating logics, summarizes its governance dilemmas, constructs a multi-scale rural spatial governance framework that is based on geographical analysis paradigm, explores feasible governance paths, and constructs a multi-scale rural spatial governance system research plan, namely, "characteristics identification-dilemma analysis-governance framework-governance path". The paper finds that: (1) to analyze the operating logics of the multi-scale rural space through the comprehensive, regional and mobile analytical thinking of geography, it is necessary to understand the mechanism of action of scale synthesis, scale differentiation and scale flow to the multi-scale rural spatial characteristics, highlighting the comprehensive characteristics of rural space, strengthening rural spatial heterogeneity, and integrating rural spatial mobility. (2) The lacking urban-rural spatial overall planning, unsmooth spatial mobile network and not-reflected different types of rural spatial value are the key dilemmas in the rural spatial governance, which need to be addressed. (3) The multi-scale rural spatial governance framework of "comprehensive spatial governance-spatial zoning governance-spatial mobile governance" could effectively solve the problems of urban-rural spatial integration, regional spatial coordination and spatial network blockage. (4) Integrating urban-rural comprehensive governance, innovating regulation control to improve regional governance and balancing the configuration of spatial development right to achieve mobile spatial governance are feasible paths for multi-scale rural space governance. In conclusion, clarifying the multi-scale rural spatial characteristics in the new era and constructing a scientific governance system could provide theoretical support to promote integrated urban-rural development and rural vitalization strategy.

The quality of development is crucial for China to comprehensively build a socialist modern country. Drawing on related concepts of development in quality, the paper conceptualizes a city in high-quality development and proposes a stylish framework with five dimensions to evaluate it, in line with the New Development Philosophy, which is composed of innovation, coordination, greenness, openness and sharing. Using the methods of spatial analysis, club convergence test and spatial Durbin model, the paper identified the spatial evolution of the quality of city development in China and associated determinants during 2005-2020. On average, the level of city development quality increased by 48.4% during the study period. The number of cities at low-level of quality in development decreased dramatically, accompanied by a profound transformation in the spatial pattern of city development quality, which presents significant spatial aggregation. The spatial imbalance remains for cities with different development qualities, and the challenge is still huge to narrow the gap. With significant role differentiation among cities, a "pioneering-catching up" pattern emerges, and the 11 pioneering cities such as Beijing, Shanghai and Shenzhen have become the pioneers of high-quality development in China. Key determinants for cities achieving high quality in development includes urbanization level, public investment, digital economy, environmental regulation and economic growth, while there is inverted U-shaped relationship between city size and development quality. To achieve the goal of high-quality city development in the new era, it is necessary to focus on the development of cities in the central and western regions, making full use of the demonstration role of pioneers, promoting quantitative growth, strengthening environmental regulations, cultivating the new forms of digital economy, and optimizing the city size hierarchy.

Global climate change caused by human activities results in frequent extreme climate events, and shifts the physiological processes of plants, and the carbon, water cycle and energy balance of terrestrial ecosystems. Vegetation phenology is the most sensitive biological indicator to climate change. In recent years, the responses of vegetation phenology to climate change mainly focus on the mean state of the climate, while the response mechanisms of vegetation phenology to extreme climate are still unclear. In this paper, the response of vegetation spring and autumn phenology to various extreme climatic events and their mechanisms were reviewed. We found that extreme low temperature and extreme precipitation directly delayed the vegetation green-up date and advanced the leaf senescence, while extreme high temperature and extreme drought led to stomatal closure, inhibited photosynthesis and transpiration, and thus advanced leaf senescence at middle and high latitudes of the Northern Hemisphere. Currently, the studies on the response of vegetation phenology to extreme climate events pay less attention to compound extreme climate events, and there are only few studies on the lag effect of vegetation phenology response to extreme climate events and the recovery process of vegetation after the occurrence of extreme events. Under future climate change scenarios, it is necessary to modify the vegetation phenological models by considering the impact of extreme climate events and couple it into the dynamic global vegetation models to improve the simulation accuracy of the carbon cycle in terrestrial ecosystems.

According to the strategic direction of urban-rural integration and rural revitalization, the spatial reconstruction of rural settlement system is the spatial organization foundation of future urban-rural integration development. This paper focused on the hierarchical scale and spatial organization characteristics of the rural settlement system. It comprehensively revealed the evolution process and regional characteristics of rural settlement systems of 111 administrative units in Guangdong province from 1990 to 2020, and discussed their evolutionary mechanism and spatial optimizing and reorganizing regional modes. The results show that: (1) There were significant regional differences in the hierarchical scale distribution of the rural settlement system in Guangdong. The patches of rural settlements show the characteristics of concentric aggregation and distribution centered on the geometric barycenter of each administrative unit. The spatial distribution pattern of the rank cumulative size coefficients of rural settlement system was "high in the southwest, but low in the northeast" and "high in coastal areas, and low in the inland". The decreasing region of the rank cumulative size coefficient was concentrated on the east bank of the Pearl River Estuary and coastal areas of eastern Guangdong, while the increasing region was mainly distributed on the west bank of the Pearl River Estuary. (2) The influencing factors such as natural background, economic development, urbanization development, transportation and location, institutions and policies jointly drove the development and evolution of the rural settlement system. Rural settlement system of urban areas is small in scale in the mature stage of urbanization, which will gradually die out and integrate into the city. Driven by urbanization, industrialization and policies, rural settlement system of suburban areas has experienced survival of the fittest and maintains a stable scale, but the mixed distribution of urban and rural land makes the spatial organization of rural settlements increasingly loose. Driven by the continuous outflow of production factors, exurb rural settlements appear to be "hollowing out". The villagers returning to build new houses and the lack of homestead exit mechanism have led to a continuous and stable growth in rural settlement scale, and their spatial distribution is characterized by more peripheral diffusion. Rural settlement system with poor location in mountainous areas develops slowly under the support of policies, and the aggregation characteristic along the transportation line is significant. (3) Facing the integrated development of urban and rural spaces, four models of spatial optimization and reorganization of rural settlement system are proposed: urban-rural integration development, dual-core-driven development, central place hierarchical system development, and pan-center chain-connecting cluster development.

According to the Ministry of Water Resources of the People's Republic of China, the number of casualties in flash flood disasters accounts for nearly 70% of flood disaster casualties in recent years and flash flood has become one of the major natural disasters causing casualties in China. Flash flood regionalization is fundamental for implementing the local measures of the flash flood prevention and mitigation according to local conditions. Using results from existing flash flood relevant physiographical regionalization schemes, and in accordance with the principles of comprehensive, dominant factors, the relative consistency within units, the relative difference between units, the integrity of spatial distribution and the hierarchical divisions, this paper firstly constructs an index system of the flash flood trigger factors and its underlying surface environment for the flash flood regionalization in China. In the combination of top-down and bottom-up regionalization, the hybrid self-organizing-map-based spatial clustering algorithm is then built. Finally, nine homogeneous regions at the first-grade and thirty-three subregions at the second-grade are delineated for flash floods in China. The historical flash flood events and the Geodetector method are adopted to evaluate the developed regionalization schemes. Results show that the first-grade and the second-grade flash flood regionalization schemes in China can respectively provide the determinant power of 66.4% and 75.4% for the spatial distribution of historical flash flood events in the whole country, indicating the developed flash flood regionalization has a good spatial consistency with the distribution of historical flash flood events with different densities. The developed flash flood regionalization not only effectively delineates the regional differentiation pattern of flash floods, but also provides a scientific basis for the implementation of localized flash flood prevention and mitigation measures in China, which benefits for the sound development of flash flood disasters prevention and management in China.

At present, the empirical analysis of regional dual-nuclei structures at the national level is still relatively rare. How to define the provinces with the characteristics of dual-nuclei structures and analyze their impact needs further empirical discussion. In this paper, the spatial Dubin model and the data of 259 prefecture-level cities are used to analyze the distribution characteristics of regional dual-nuclei structure in China and its influence on provincial development. The empirical results show that 11 provincial-level regions (hereafter provinces) in China show the characteristics of dual-nuclei structure. The regional dual-nuclei structure plays a significant role in promoting the economic development of the province, but the northern and southern regions show great differences. The regional dual-nuclei structure has a promoting effect on provincial industrial agglomeration and helps to promote the improvement of local scientific and technological innovation. In general, compared with some single-core provinces with small scale and weak radiation driving force in some provincial capitals, the regional dual-nuclei structure can make up for these shortcomings to a certain extent by virtue of the number of central cities and spatial distribution, which is more conducive to driving local economic development and scientific and technological innovation.

As the third pole of earth, the Qinghai-Tibet Plateau is an important ecological security barrier in China and an ecologically sensitive area of global climate change. The increasing climate change has posed a major challenge to its ecosystem function and stability. This paper first analyzes the spatiotemporal variation characteristics of the ecosystem pattern of the Qinghai-Tibet Plateau and its key functions including water conservation, soil conservation, windbreak and sand fixation from 2000 to 2020, clarifies the regional differences in ecosystem functions and their importance, and further evaluates the stability of ecosystem functions. And there is no doubt that the stable state will lay a scientific foundation for the plateau to build an ecologically civilized highland and launch protection and restoration projects. The results show that: (1) From 2000 to 2020, the wetland area of the study area increased and the grassland area decreased significantly. The water conservation and windbreak and sand fixation capacity were improved, and the annual change rates were 3.57 m³/(hm²·a) and 0.23 t/(hm²·a), respectively. However, the overall soil conservation showed a downward trend with an annual change rate of -0.16 t/(hm²·a). (2) The core areas of water conservation, soil conservation and windbreak and sand fixation accounted for 12.7%, 13.9% and 14.2%, respectively. The core water conservation barrier areas were mainly located in southeast Tibet, Sanjiangyuan and Ruoergai. The core windbreak and sand fixation areas were concentrated in the central and western parts of the plateau, and the core soil conservation areas surrounded the plateau. (3) From 2000 to 2020, the water conservation, soil conservation, and wind protection and sand-fixation functions have shown relatively high stability in the southeastern and central parts of the plateau, while relatively weak stability in the western part of the plateau. Combining stability assessment and ecological protection and restoration practices, we can divide the Qinghai-Tibet Plateau into three major categories of 16 ecosystem function zones and carry out differentiated ecological protection and restoration for different core ecosystem functions and zones.

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

Urban-rural integrated development is an advanced stage in the evolution of the urban-rural relationship, and it is also the basic path and main goal for the implementation of rural revitalization. Scientifically understanding and identifying the integration stage and its current level of urban-rural development in China is the prerequisite basis for promoting urban-rural integrated development and rural revitalization. Based on the concept connotation, this paper constructed a multi-dimensional evaluation system of urban-rural integrated development at the prefecture level. The process status and spatiotemporal divergent characteristics of urban-rural integrated development in 336 prefecture-level regions in China from 2000-2018 were portrayed and revealed. The results show that: (1) The current state of urban-rural integrated development in China is generally at a low-to-middle level, showing a heterogeneous spatiotemporal pattern with apparent gradient divergence. The integrated development level of the Pearl River Delta, Jiangsu and Zhejiang provinces, and the Shandong Peninsula is high, but the regions distributed to the west of the "Hu Line" develops slowly. (2) According to the level and characteristics of integrated development, the 366 prefecture-level regions can be divided into four types: integrated development, tending integration, imbalanced development, and lagging development, with a more active transformation between the latter three types. (3) The development level of urban-rural economic integration is higher than that of demographic and social integration, while the development process of urban-rural spatial and ecological integration shows some natural zonal divergent characteristics. Finally, we identified the problem areas for different types of integrated development and explored the regional promotion path of urban-rural integrated development, which could provide scientific references for the strategies of regional urban-rural development and rural revitalization.

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.

Soil organic carbon (SOC) storage and soil carbon sinks play a crucial role in the global carbon cycle of terrestrial ecosystem. However, many previous studies of soil carbon storage and sinks utilized low-resolution land use dataset, with limited focus on soil carbon sinks from farmland and grassland management. To address this issue, this study employed a series of accounting models to estimate the carbon sink from farmland and grassland management, the carbon sink from forest management, changes in soil carbon storage, changes in carbon storage due to land use conversion from 2000 to 2020, as well as the soil carbon storage in China in 2000 and 2020 using a 30 m-resolution land use dataset. The results showed that the national carbon sink from farmland management in China was approximately 17.918 Tg C a^-1 and the carbon sink from grassland management was approximately 20.171 Tg C a^-1 during 2000-2020. The carbon sink from forest management in China was approximately 81.622 Tg C a^-1 during 2000-2020. The soil carbon storage (0-100 cm) in China increased from 86.074 Pg C in 2000 to 86.771 Pg C in 2020. The soil carbon storage increased by approximately 34.850 Tg C a^-1 from 2000 to 2020. The land use transformation during the study period resulted in a decrease of approximately 17.621 Tg C a^-1 in soil carbon storage. The findings of this study can help researchers understand China's carbon storage and provide scientific data to China's 2060 Carbon Neutrality Target.

With the increasing global warming over the past three decades, the climatic zones and eco-geographical regions characteristics in China have changed. This study used the climatic data of 641 meteorological stations over the past three decades (1991-2020), as well as the high-precision data of eco-geographical elements to optimize the eco-geographical regions in China. The study updated the map of eco-geographical regionalization in China (2023) and increased the scale to 1:4000000. The new map divided China into 11 temperature zones, 22 dry and wet regions, and 50 natural regions. The results show that compared with eco-geographical regionalization in 2007, the overall pattern of eco-geographical regions in China has not changed significantly over the past three decades, but the boundaries of temperature zones, dry and wet regions, and eco-geographical regions (natural regions) in some areas have changed to some extent. Firstly, the boundary change of temperature zones is more obvious in the east. Particularly, in the middle and lower reaches of the Yangtze River, the northward shift of the temperature zone boundary between the northern subtropical and the mid-subtropical zones is obvious. Secondly, the boundary between dry and wet regions has changed, and that between semi-arid and arid regions in the north of the second-order landform step has shifted slightly to the west. In addition, the boundary between semi-arid and sub-humid regions in the Qinghai-Tibet Plateau has shifted slightly to the southeast, reflecting a slight expansion of the scope of semi-arid regions. Finally, boundary changes in natural regions in some areas vary greatly. This study can provide a macro-regional framework for guiding ecological conservation and restoration in different regions.

Subsurface stormflow is a special form of subsurface flow in the vadose zone of steep slopes in mountainous and hilly regions, and it is also one of the most important runoff generation mechanisms in the process of flash flood formation. However, the systematic summary on the scientific connotation, mechanisms, and disaster-causing characteristics of the subsurface stormflow in current research is very rare and this limits the development of the theoretical system of runoff generation, routing, and modeling methods of flash floods. Herein, we clarify the scientific connotation and definition of subsurface stormflow based on the division of the development periods of the subsurface stormflow research around the world as well as the analysis of physical processes for the runoff generation. Meanwhile, three physical conditions for the occurrence of subsurface stormflow, together with their influences on the nonlinear response process, are highlighted. The influences of the subsurface stormflow on the dynamic development of flash floods, landslides, and debris flow hazards are analyzed and summarized. Finally, three key research directions are proposed: water transport processes and hydrological connectivity mechanism of the macropores in the vadose zone, processes and mechanisms of water exchange at the geotechnical channel interfaces inside the slopes, and the formation mechanism for flash flood from multiple runoff generation processes with complex slope topography conditions. This work can provide new research perspectives for the formation mechanism and hydrological theoretical framework of flash floods in complex mountainous regions, and better support the national scientific and technological needs for flash flood forecast as well as disaster prevention and mitigation.

Geographic big data enables a fine-grained depiction of regional human-terrestrial systems and provides new data for the study of human-terrestrial relations and regional development. At present, geographic big data research has entered the stage of widespread application, but the examination of its quality and the corresponding evaluation methods have been lacking to guarantee the widespread and efficient application of the data. POI is an important part of geographic big data and plays an important role in location-based services and an understanding of regional scenarios. This paper proposes a method to assess and enhance POI-type big data, and realize quality evaluation based on site research, GIS and other methods from three dimensions: feature identification completeness, data redundancy rate and spatial location accuracy; discover and summarize possible influencing factors of data quality based on data production process, and prove that multi-source data fusion is an effective means to enhance POI data quality. We found that: the volume of Amap data acquired based on API interface is slightly higher than that of Baidu, the accuracy rate of spatial location is comparable and the redundancy rate is lower; Amap focuses on identifying the entrance of features, which is suitable for analysis such as accessibility; Baidu focuses on discovering non-significant features, which is suitable for analysis such as spatial planning; the discovery, acquisition and processing stages are possible links to reduce data quality, which is influenced by data protection mechanism, and the data quality is inversely proportional to the acquisition volume and area. The quality assessment, enhancement and integration of multi-source heterogeneous geographic data is one of the key ways to enhance the "emergent value" of data, promote trans- and cross-multidisciplinary and solve geographic problems in the new era.

Sedimentary DNA has been widely used in the studies of climate change, ecological function, and environmental archaeology, because it can provide biological dynamic information with temporal dimension in geographical environment. However, the surface processes and impact factors of sedimentary DNA within the catchments are still not fully understood, which limits the accuracy of sedimentary DNA data interpretation. In this study, topsoil DNA concentrations at the Buha River catchment in northwest Qinghai Lake, which was suitable for DNA preservation, were firstly measured based on domestic new sedimentary DNA laboratory. Meanwhile, soil physical and chemical compositions, including grain size, elements, loss on ignition and TOC, were determined. Subsequently, the abiotic factors which had impact on spatial distribution of topsoil DNA concentration were analyzed by combing the status related with climate, vegetation cover, and land use at the Buha River catchment. The results showed that the average concentration of topsoil DNA at the whole catchment was 0.91 μg/g, with the higher values in the middle reaches of the Buha River and its tributary Jilmon River, while the lower ones in the lower reaches near the Qinghai Lake. In addition, topsoil DNA concentrations at the catchment were positively correlated with the contents of clay and organic matter, but negatively correlated with sand content and the intensity of weathering and leaching. Besides, high vegetation cover and frequent grazing activities contributed to the enrichment of the topsoil DNA, while strong weathering and leaching under warm and wet environment, river transportation and crop cultivation reduced the concentration of the topsoil DNA. All the above results provide a scientific basis for an understanding of the deposition processes of sedimentary DNA and their impact factors in the Buha River catchment, which are helpful for revealing sedimentary DNA compositions and evolution processes of ecological environment and human-environment relationship in regions west of the Qinghai Lake.

Economic globalization has reshaped the world economy's spatial pattern while simultaneously changing the context for developing economic geography theories. This study revisited the changing features of economic globalization and investigated its geographical implications. Next, it summarized the new trends in economic geography studies in response to the changing economic globalization. Lastly, this study proposed a research agenda for domestic economic geography studies by combining the requirements of global trends and national strategies. The main findings include the following: The scale of geographical integration during economic globalization keeps shrinking, leading to a pattern of regionalization. The driving forces of economic globalization have gradually shifted from cost-saving to innovation. Accordingly, the benefits of economic globalization will be reallocated between developed and developing countries. The trade-offs between efficiency and resilience alter the global value chain, shifting outsourcing from off-shoring to re-shoring or near-shoring. The changing economic globalization has witnessed the rising effects of geographical distances, institutions, and resilience on increasing the inequality of the global economic geography. In economic geography, the scalar structures shifted from the global-local to the global-national-local. The relational networks evolved toward a multi-level, multi-agent, and multi-scale one. The role of the nation has been revisited. More attention has been paid to geopolitical hotspots. Overall, economic geography's institutional, cultural, relational, and evolutionary turns exhibit an emerging trend to convergence. In such a setting, domestic economic geography should find a new balance between global trends and national strategies. This study proposed seven research issues, including: (1) the practice of the Belt and Road and the pattern of inclusive globalization; (2) the economic geography of dual circulation; (3) the paths and resilience of regional development in response to the global production network restructuring; (4) the evolution and competitiveness of industrial clusters; (5) the building of multi-level innovation systems; (6) the regional sustainable development within the global environmental governance system; and (7) the impact of geo-economics on national economic security and interests.

The Hanjiang River, located between the Qinling and Daba mountains, connects the Hanzhong, Ankang and other intermontane basins where there are numerous paleolithic sites. Here is an ideal area to explore the impacts of geomorphic processes on hominin activities. In this study, based on loess stratigraphy, magnetostratigraphy and detrital zircon U-Pb geochronology, the age of high terraces in the Ankang basin and the time of the drainage connection of the Ankang and Hanzhong basins by the Hanjiang River from west to east was determined. In addition, the possible influence of the evolution of landform and drainage network pattern of the Hanjiang River on the hominin occupation in the southern Qinling Mountains in the context of orbital scale climate change is discussed. The results show that (1) Eight terraces of the Hanjiang River were developed in the Ankang basin, with the sixth forming at ~1.82 Ma; (2) Most of these terraces were formed during the climatic transitions from interglacial to glacial periods, and more terraces were formed under the conditions of the Mid-Pleistocene climate transition (MPT) and the increase of uplift rate of the Qinling Mountains since 1.2 Ma; (3) It was not later than 1.82 Ma when the Hanjiang River connected the Ankang and Hanzhong basins as a result of river capture from east to west. River capture and the resulted connections of intermountain basins provided convenient geomorphological conditions for hominins to migrate into the Qinling and Daba mountains along broad river valleys since ~1.5 Ma, and thereafter fluvial terraces provided beneficial space for hominin activities.

There are important changes in urban-rural structure of population mobility at the late-intermediate stage of urbanization in China, which will have a significant impact on population redistribution, urbanization and regional development. This paper divides the interprovincial urban and rural floating population into four mobility types by using the 2010 and 2020 censuses data, and on the basis of identifying the mainstream types, their spatial patterns evolution and the relationship with regional economic development are investigated through the mobility ratio indexes and regression models. The study results can be summarized as follows. (1) The urban and rural floating population is large and grows rapidly. Meanwhile, rural-urban mobility keeps the dominant position, and urban-urban mobility rises rapidly, these two population mobility types have become the mainstream ones of interprovincial urban and rural floating population in China. (2) In terms of the net mobility pattern of urban-urban floating population, the net-inflow areas are further concentrated in the three major coastal centers of Beijing, Shanghai and Guangdong, and Liaoning, Xinjiang and Yunnan are also maintained at a certain net-inflow rate, but most of the provincial-level regions are in the net-outflow areas. The major changes of the net mobility pattern of urban-urban floating population have shaped a spatial connection network. The main features of this network can be described as three cross-regional flow circles of Beijing-Tianjin-Hebei, Yangtze River Delta, and Pearl River Delta in coastal China. At the same time, the space connections within the regions are strengthening in northeast China, northwest China and southwest China. (3) The net mobility pattern of rural-urban floating population shows that in coastal areas, the net-inflow rate rises or decreases during the study period, while in inland areas, the increase in the net-inflow rate of Liaoning and Xinjiang leads to the decline in the net-outflow rate of their neighboring provinces. The changes of the net mobility pattern of rural-urban floating population depict the dual characteristics of continuous formation and different changes of the coastal flow circle, and the development of the inland flow circle in Xinjiang and Liaoning. (4) There is a mutual relationship between urban-urban and rural-urban population mobility and regional economic development. For regional economic development of both population mobility types, the impact is significantly positive and has been increasing. When we add the floating stock into the models, the positive effect of this variable has decreased in urban-urban mobility's model, while it still plays the first-place positive effect in rural-urban mobility's model. The two population mobility types have a positive effect on the national economic development and the inflow areas' economic development.

Soil moisture is a key driving factor that affects vegetation growth. Vegetation reacts to soil moisture through processes such as evapotranspiration. In-depth exploration of the interaction between soil moisture and vegetation GPP is crucial to ensuring the sustainable development of ecosystems and the efficient utilization of water resources. This study employed MODIS GPP, ERA5-Land soil moisture, and other data sources. It utilized an enhanced nonlinear Granger causality model, along with partial correlation analysis, Sen's slope, and the Mann-Kendall method. These methods were used to examine the combined changes in GPP and soil moisture and their mutual feedback relationship across diverse vegetation types in China from 2000 to 2021. The results showed that: (1) Since 2000, 50.89%-57.61% of the vegetated areas in China have shown a synergistic trend of increasing GPP and decreasing soil moisture, which exhibited a greater proportion with increasing soil depth. The proportion of areas with consistently increasing trends in both GPP and soil moisture was 39.03%-45.76%. (2) In 59.88%-79.38% of vegetated areas, both GPP and soil moisture showed a bidirectional Granger causal relationship. This proportion decreased with soil depth, notably in temperate grassland areas (R6) and temperate desert regions (R7). (3) The increase in GPP resulted in a more significant consumption (57.03%) of soil moisture at 100-289 cm depth and a longer lag effect (2.15 months). Soil moisture at a depth of less than 100 cm mainly promoted the increase in GPP (71.43%-76.58%) and only showed inhibitory effects in some areas, such as the Tianshan Mountains and Hengduan Mountains. The promoting effect of soil moisture at 100-289 cm depth on the vegetation GPP (48.31%) weakened and was accompanied by a significant increase in the lag effect (2.92 months). (4) As the precipitation increased, the interaction between vegetation GPP and soil moisture gradually decreased. When the precipitation was between 200 mm and 400 mm, the interaction was most significant. The influence of different temperature gradients on the interaction between vegetation GPP and soil moisture exhibited multiple threshold effects. This study helps to deepen our understanding of the interaction between carbon and the water cycle of the terrestrial ecosystem in the context of climate change. It also provides an important theoretical reference for the implementation of future ecological restoration projects and the sustainable development of ecosystems.

Terrestrial recycling of green water, which is created through a continuous cycle of evapotranspiration, atmospheric transport, and terrestrial precipitation, serves as bridges connecting hydrosphere, atmosphere, biosphere, and anthroposphere. Limited knowledge of terrestrial recycling may underestimate the impact of human activities on water and ecology. This study focuses on the structure of China's green water recycling (CGWR) and quantifies the contributions of natural and human ecosystems. Results indicate a high green water recycling ratio (50.4%) and a large recycled amount (2.75 trillion m³/a) over China, with significant south-to-north transport structures over eastern China, southwest-to-northeast transport structures from southwestern China to northern China, and high self-recycling structures in western China. The grassland-dominated Qinghai-Tibet Plateau provides the largest amount of green water (about 800 billion m³/a) and serves as the most critical region for CGWR. The forest-dominated southern hilly region and Yunnan-Guizhou-Sichuan region play a crucial role in supplying green water to a wide area of China. The cropland-dominated Middle-Lower Yangtze Plain and the grassland-dominated Loess Plateau are the key hubs for south-to-north and southwest-to-northeast transport of green water. The structure of CGWR is driven by large-scale geosystems such as ecosystems and atmospheric circulation systems, and has strategic implications in the following three aspects. First, CGWR serves as the "domestic cycle" of water, based on which a general domestic-level water governance framework can be established. Second, CGWR is a representative picture of the water-related processes in the Mountain-River-Forest-Farmland-Lake-Grassland-Desert (MRFFLGD) system and serves as a critical pivot to actualize the conservation and improvement of the MRFFLGD system. Finally, CGWR, together with inter-basin water resources transfer and virtual water transfer, forms a complete picture of China's inter-basin water transfer. The scientific coordination and integration of the three processes present a new approach for achieving spatial equilibrium between China's water resources and economic development.

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

Danxia landscapes are a landscape feature with the Danxia landform as the main body, and are widely distributed in China. An in-depth understanding of the landscape differentiation on a national scale is essential for the protection and utilization of Danxia landscapes as tourism resource. Based on data such as lithology, cliff height, stratum attitude, rock strength, and other data, this study quantitatively analyzes the spatial pattern of Danxia landscapes. Combining these data with the understanding from an on-site survey of more than 200 Danxia landforms across the country, the differentiation of Chinese Danxia landscapes is semi-quantitatively determined. Based on multiple geologic and geomorphologic factors, the Danxia landscape in China is divided into six distinctive regions: Southeast China, the Sichuan-Chongqing-Guizhou junction, the Ordos Plateau, the southwestern Ordos Basin, "Tianshan-Qilian", and the Qinghai-Tibet Plateau. Through the national-scale comparison of Danxia landscapes, six key characteristics are noted. The basin size of red-bed deposits and the crustal uplift and subsidence during the Himalayan movement jointly controlled the spatial distribution of the Danxia landforms, while the tectonic deformation characteristics in different regions controlled the inclination of strata. The spatial lithological differences among different types of the basins affect the slope morphology. Rock strength has little effect on cliff height, but the difference in vertical rock strength affects the slope shape, which in turn affects the geomorphological process. The landform evolution stages affect the richness of individual and group landscapes. Finally, climate influences the currently active geomorphic processes, and the combination of vegetation and landforms in different climate zones shapes different Danxia landscape features and aesthetics. Nationally, the spatial distribution of Danxia characteristics is a regional manifestation of tectonic evolution, Earth's surface environment, and other factors.

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

Ensuring food security under the "double carbon" goal is an important issue for China to tackle climate change and build a community of human life. This paper employs the life cycle assessment method to gauge the grain production carbon emissions in China and its 31 provincial-level regions from 1997 to 2020, and uses the Dagum Gini coefficient, standard deviation ellipse and kernel density methods to explore the dynamic evolution characteristics. It further identifies the underlying factors of China's grain production carbon emissions, as well as their spatio-temporal impacts, under a comprehensive, period-based, and regional-level decomposition perspective. The results show that: (1) During the inspection period, China's total carbon emissions from grain production showed an upward trend, with an annual growth of 1.30%, yet since 2017 it has been in a continuous downward trajectory. Material inputs and straw burning account for the lion's share of emissions. The total carbon emissions in 2020 amounted to 494.78 million tons. (2) With regard to the three major grain production functional areas and six grain crop planting system areas, the carbon emissions of grain production in the main grain production areas, the middle and lower reaches of the Yangtze River and North China provinces have been in the forefront during the investigation period, while those in the main grain sales areas have displayed a diminishing trend. (3) The absolute difference of China's grain production carbon emissions enlarged manifesting as a tendency of high level convergence and widening of regional disparities. (4) China's grain production carbon emissions are jointly affected by economic, social, technological, demographic and natural factors. With gross agricultural output value and gross grain output serving as the key influential factors, they display negative spatial spillover effects; meanwhile, regional economic structure, labor saving technology, and agricultural production composition demonstrate diametrically opposite effects. The stage effect takes the 11th Five-Year Plan period (2006-2010) as the node, and the driving factors tend to be simplified. In the regional effect, the driving factors from the main sales area, the main production area to the balanced production and marketing area tend to be complex. This study provides a theoretical and methodological basis for promoting green grain production under the "dual carbon" strategy.

Resilience study has long been a focal point in various fields of geography, social science, urban studies, and psychology. Recently, resilience study from multiple disciplines has scrutinized at individual scale. As an important behavior in daily life of human beings, travel behavior is of spatial dependence, spatio-temporal dynamics, and individual heterogeneity. Moreover, how to understand interaction between travel behavior (demand) and traffic supply and their dynamics is a fundamental question in transport studies when transport systems encounter unexpected disturbance. Based on fundamental theories from multiple disciplines including ecology, traffic engineering, and psychology, this paper refines the definition of travel behavior resilience. Also, this paper proposes a conceptual theoretical framework of travel behavior resilience based on dynamic equilibrium characteristics of traffic supply and demand. In general, travel behavior presents three stages of variations, namely, dramatic reduction, rapid growth, and fluctuation recovery, which has been helpful to capture travel behavior resilience triangle. Then we construct a corresponding evaluation methodology, which is suitable for multi-scale and multi-dimensional perspectives. We emphasize that the evaluation of travel behavior resilience should be process-oriented with temporal continuity or capture inflection points of travel behavior. Using multi-source big data such as mobile phone signaling data and smart card data, this paper offers empirical studies on travel behavior resilience, and explores its spatial heterogeneity and group differences. With the location-based analysis, we confirm that people show the greater travel behavior resilience at places where people are engaged in various socio-economic activities. With the group-based analysis, we find that age, socio-economic attributes of mobility groups significantly affect travel behavior resilience. Overall, travel behavior resilience can be one pillar and also offer geographic perspectives to broaden resilience studies. In future, the study of travel behavior resilience on multiple scales and perspectives can explore spatial heterogeneity of traffic re-equilibrium, transport modal differences, and then contribute to urban spatial structure studies. Indeed, the study of travel behavior resilience can provide scientific and technological support for urban management and resilient city construction.

Wetland is an important natural resource for human beings and plays an irreplaceable ecological function in the terrestrial ecosystem. In order to curb the continued loss of wetlands around the world, international organizations and many countries have taken a series of major protection and restoration measures. This paper reviews the wetland protection and restoration measures of international organizations and some countries, comprehensively interprets China's wetland protection and restoration management experience, and proposes that future research on wetland resources should be carried out from the aspects of international frontier and national strategy, social economy and intelligent services. The results show that: (1) The 27 International Wetlands Day from 1997 to 2023 provide new goals and tasks for the protection and management of wetlands in corresponding years. The important topics and outcomes of the 14 International Convention on Wetlands Conferences from 1980 to 2022 provide new directions and new challenges for wetland development in the coming period. In the future, we should enhance ecological functions of wetlands, promote the sustainable development of wetlands, and overcome the technical bottleneck of ecological restoration of fragile wetland ecosystems from 2020 to 2035. (2) During the 30-year period from 1992 to 2022, China embarked on a new phase of wetland protection and restoration. The overall experience of wetland protection and restoration with Chinese characteristics has been formed through "national strategic deployment-legal policy establishment-project planning and implementation". Emphasis was placed on the need to provide for and prepare planning for the long-term protection of wetlands at the national legal level, to innovate restoration and management techniques and application systems, and to effectively address the complex issues of wetland protection and restoration through collaborative division of labor among multiple departments. (3) The research on the future trend of wetlands should be directed towards the exploration and practice of "United Nations Sustainable Development Goals and several international conventions" in support of the sustainable development of wetlands. Wetland protection, restoration and management services should be promoted for "national strategic needs and local social and economic high-quality development". Research on the cross-integration and academic innovation development also should be enhanced for "disciplinary development - global supervision - comprehensive assessment-intelligent decision-making".

Regional economic resilience is closely related to the state of the regional industrial structure. During the process of the region undergoing and recovering from external shocks, whether and how the spatio-temporal correlation between economic resilience and the evolution of the established industrial structure should be further explored. The micro and mesoscopic views of enterprises and industries, multi-year economic growth data, and enterprise status in the counties of the Beijing-Tianjin-Hebei region were employed to measure regional economic resilience at the county level and divide its economic development stages. In addition, a spatio-temporal correlation between regional economic resilience and industrial structure was appropriately tested, and the main industries affecting regional economic resilience were distinguished. Finally, the coupling mechanism of regional economic resilience and industrial structure evolution was analyzed. The major findings are as follows: (1) The periods of rapid and slow economic growth occur alternately in the study region, and the economic resilience shows a fluctuating growth trend. Meanwhile, central urban areas such as Beijing, Tianjin, and Shijiazhuang exhibited high economic resilience, and a typical center-periphery structure gradually took shape. (2) There was a significant spatial correlation between regional economic resilience and industrial structure. In economically developed regions, such as Beijing and Tianjin, the agglomeration of high economic resilience and high industrial structure was evident. There was a two-way causal correlation and consistency in time-series changes. (3) The industrial structure in the Beijing-Tianjin-Hebei region had gradually improved. Compared to the effect of industrial structure, the effect of competitiveness contributed more to economic resilience. Primary industries as well as those pertinent to consumer services and social services have played a pivotal role in improving regional resisting economic resilience. Besides, the development of consumer services and social services leads to the strengthening of the region's recovering economic resilience. (4) The evolution of the industrial structure achieved the evolution of the development path, which was revealed in the distinction of economic resilience at the county level. In addition, the coupling correlation between regional economic resilience and the evolution of industrial structure in the study region was mainly revealed in the time scale, which had not yet led to the fundamental restructuring of the regional spatial structure, and the center-periphery structure is still relatively significant.