As an important economic form for the innovation and development of human society, since the 21st century, the low-altitude economy has become one of the key ways to promote China's modern industrial development, with its unique charm and broad application prospects. Research on the low-altitude economy of manned vehicles has a long history. However, this research is still growing; and there are many ambiguities within the human-cultural research of low-altitude economies. Therefore, it is necessary to review the existing results so as to promote the development of a theoretical and methodological system for low-altitude economic research. Based on data from the Web of Science (WOS), Scoups, and CNKI databases with the low-altitude economy as the research theme, the CiteSpace software was used to comprehensively sort out the publication status, research content, and research lineage of domestic and foreign low-altitude economy research. This study analyzes and summarizes the characteristics of the publication, subject matter, and characteristics and trends of the various phases. The results show that: (1) Although the leading figures and research teams of domestic and foreign low-altitude economy research have initially appeared, there are fewer cross-institutional academic contacts and a broad academic consensus is yet to be formed. (2) There are also differences in the development history and research characteristics of domestic and foreign low-altitude economy research, but in the early stage of the research, the focus is mainly on general aviation. It then moves to a new era of drone dominance that is centered on the low-altitude economy after 2010. (3) As is, foreign studies have focused on, for example, the exploration of UAV models and their engineering technology, UAV traffic management systems, UAV application scenarios. On the contrary, Chinese studies focus on the reflection and summary of the reform of low-altitude airspace, construction of UAV systems and their industrial development, etc. (4) The directional shift of the low-altitude economy from the natural space to the human-cultural space is an important feature in this growth period but the current low-altitude economy research on human culture is still in the trial phase. Therefore, it is recommended that scholars establish a scientific system suitable for the development of low-altitude economies in China, expand research perspectives and interdisciplinary cooperation, and strengthen extensive communication and exchanges among scholars, which helps construct a diversified inter-institutional, interdisciplinary, and inter-geographical cooperation network. In addition, it will deeply excavate the human-earth relations and spatial organization concepts in the study of low-altitude economies and integrate natural-social-economic-humanities perspectives on intelligent, synergistic, and sustainable development of UAVs, as well as systematically expose the UAV industry chain, UAV-related supporting facilities, market consumption, and public attitudes. This study aims to accelerate the high-quality development of China's low-altitude economy and comprehensively promote its modern development.
Coastal nebkhas are an important component of coastal sand dune ecosystems, widely distributed at varying scales, and the key subject of coastal aeolian geomorphology research. This paper systematically reviewed the morphological characteristics, developmental evolution, and dynamic processes of coastal nebkhas, summarizing the major advancements in research and technical methods both domestically and internationally. Key findings include: the establishment of dune developmental stages based on the correlation of dune morphological parameters (horizontal scale and height); the volume of coastal nebkhas is related to wind and sand activity, ocean dynamics, and biological factors; the dune formation mechanism is a coupled process consisting of wind-driven dynamics, sand source supply, and vegetation stabilization, with coastal environments indirectly influencing dunes through vegetation and wind-sand interactions; the relative importance of different factors varies across regions during dune development; airflow and its interaction with shrub dunes exhibit significant differences in various dune parts, with windward slopes generating reflective eddies that enhance wind speed, and leeward slopes forming horizontal and vertical vortices. Vegetation species type, coverage, density, and distribution all affect near-surface wind-sand movement, with the highest sand deposition typically occurring near vegetation on the windward slopes, where sand transport decreases. A technical approach combining observational and simulation studies has shaped the research, especially with the recent application of new technologies, such as Unmanned Aerial Vehicle measurement systems and computer simulations, which have significantly advanced the study of coastal nebkha morphology, airflow structure, and sediment transport patterns. However, current research faces three main limitations: an incomplete understanding of the development mechanisms of coastal nebkhas, and a need for deeper exploration into their dynamic mechanisms. In the future, the focus should be on combining traditional observations with modern emerging technologies to strengthen the study of the main limiting factors and their interaction mechanisms during the formation and development of nebkhas and deepen the understanding of their formation and development mechanisms in China. Through comprehensive field surveys, typical investigations, and morphological measurements of key distribution areas of coastal shrub dunes, multi-scale, long-term, continuous dynamic monitoring should be conducted. It is important to analyze the formation and evolution mechanisms of coastal nebkhas in different regions, providing a scientific basis for cross-regional dune management and protection. A comprehensive study of the joint action mechanisms of wind dynamics, hydrodynamics, particle adhesion, and biological forces is essential to reveal the spatiotemporal dynamic evolution patterns of coastal nebkhas in China, both annually and inter-annually. Furthermore, the influence mechanisms of vegetation ecological processes, human activities, and climate change on coastal nebkhas should be emphasized, addressing the gaps in domestic research and improving the research framework for coastal aeolian geomorphology in China.
Study of the history of Chinese geography has lasted for over a century, providing different historical interpretations to the two less studied fundamental issues of "the similarities and differences between China and foreign countries" and "the transformation from the ancient to the modern". Focusing on representative research, this paper explores the research presuppositions, methodology, and contents that are linked to them, revealing the evolution of research approaches for these two fundamental issues. Over the past century, four research approaches have formed in the study of the history of Chinese geography. First, the analogical interpretation approach, which used the connotation of traditional Chinese geography to understand modern geography introduced from abroad and concluded that modern Chinese geography was based on its ancient traditions, but only existed in the early 20th century. Second, the reverse analogical interpretation approach, which aimed to construct an ancient Chinese geographical knowledge and disciplinary system that conformed to modern geographical standards. It had multiple understandings of "the similarities and differences between China and foreign countries" in the 1930s to 1940s, but became monotonous after the 1950s under the influence of Wang Yong's radical views, thereby reconstructing the ancient system of Chinese geography in the modern sense; this approach faced narrative obstacles in explaining its autonomous early modernization. Third, the restoration approach, which emerged in the 1990s, was based on criticizing the anterior monotonous approach. It restored the social, ideological, and cultural significance of ancient Chinese geography, namely the dynastic geography from the perspective of contextualism on the level of the history of ideas and constructed its content system. So far, the early modernization of Chinese geography relied on the explanation of the communication theory of social, cultural, and institutional transformation. Fourth, the circulation approach, a new breakthrough in the study of the history of Chinese geography, revealed the gradual early modernization of Chinese geography through the collision, integration, and renewal of Western geography with China as subject from the perspectives of global history and the history of the circulation of scientific knowledge, breaking through the narrative obstacles of the theories of communication and revolution regarding the early modernization of Chinese geography. Although each of the four research approaches has its own specific object of observation, the evolution of the critical layers constitutes a more comprehensive perspective for understanding the history of Chinese geography. Under the trends of global histories of science, it is necessary for the study of the history of Chinese geography to rethink the significance and nature of the two fundamental issues mentioned above to avoid the centralized frameworks and discourses, to emphasize the relationship between geographic traditions and the socio-cultural scenarios, to highlight the history of circulation of Chinese and Western geography on the level of the knowledge networks, and to reveal the tasks that deserve attention in the study of the history of Chinese geography.
The first half of the 20th century was a critical period in the transformation of Chinese geography from tradition to modernity. The geography departments of higher education institutions, as the main organizations for research and teaching in Chinese geography at the time, reflected the developmental trajectory of geography in China. Although research has yielded certain scholarly achievements, three notable limitations persist in current academic investigations. First, it places excessive emphasis on "establishment" events while neglecting dynamic processes, such as "disciplinary restructuring," "institutional reorganization," and "closure," thus failing to fully capture the complexity of academic department development. Second, owing to incomplete historical materials, there are significant discrepancies in the statistical counts of academic departments, which often include non-geography departments or proposed departments that were never operational. Third, insufficient attention to geography departments in normal universities and their structural transformations within the discipline has resulted in an incomplete understanding of the pathways toward disciplinary specialization. This study adopts a chronological approach that integrates and utilizes diverse sources of materials, including the National Education Yearbooks, university statistical data, admission guides, institutional historical archives, memoirs, enrollment records, and contemporary research findings. Cross-validation identifies the years of establishment, restructuring, reorganization, and closure of geography departments, thereby clarifying their founding, restructuring, reorganization and closure processes. This study further analyzes their quantitative characteristics, developmental stages, institutional affiliations, and disciplinary structures. The research findings indicate the following: 1) Regarding the number of departments established, it has been confirmed that 52 universities and colleges founded 63 geography departments, a figure significantly higher than that reported in existing studies (Approximately 40). This discrepancy arises from two aspects: on the one hand, existing studies fail to fully account for the restructuring and reorganization of geography departments; on the other hand, eight previously overlooked geography departments in universities have been included. 2) The establishment process can be divided into four stages: 1904–1928 (initial establishment period), 1929–1936 (period of minimal expansion), 1937–1945 (period of moderate expansion), and 1946–1949 (period of slow expansion). The overall trajectory across these stages is characterized by slow growth amid frequent cycles of founding, restructuring, reorganization and closure, with fewer than half of the established departments remaining operational by the end of the period. 3) Regarding departmental distribution, the majority were located in universities and normal colleges, with a high proportion in normal colleges. From 1904 to 1928, geography departments were mainly located in normal universities, whereas a new trend emerged from 1929 to 1936, with their affiliation shifting toward the faculties of science in universities. 4) Regarding the disciplinary structure, significant differences exist between different types of institutions; university geography departments are primarily aligned with geology and meteorology. Clearly defined differences in disciplinary structure can be observed across different periods, especially pronounced between 1929–1936 and 1946–1949, where independent department characteristics emerged distinctly. Normal universities display a prominent association with history and geography, with earlier instances of interdisciplinary association with Chinese literature, history, and natural sciences. Through multisource historical evidence corroboration and chronological textual research, this study comprehensively illuminates the developmental process of geography departments in China. First, it corrects the number of geography departments, highlighting the academic contributions of marginal institutions. Second, it divides development into four stages, demonstrating the impact of warfare and policies on the rise and fall of these departments. Additionally, it tracks the transition from integrated to independent systems, illustrating the process of scientific development in geography. Ultimately, these findings provide a foundational basis for researching the history of modern Chinese geography, educational policies, and academic systems, while also offering historical references for contemporary disciplinary construction and institutional planning.
Historical physical geography is a discipline that investigates the changes in various natural factors within geographical environments during historical human periods. The establishment of modern Chinese historical geography was profoundly influenced by Western historical geography theories and methodologies, particularly those of the Anglo-Americans. However, the English-speaking academic world lacks a distinct disciplinary framework analogous to that of "historical physical geography" (such as the term "historical physical geography" itself remains exceptionally rare). This discrepancy relates to the fact that historical physical geography, a crucial component and subfield of Chinese historical geography, originated from knowledge exchanges with Soviet theoretical frameworks in the early 1950s. The organizational model of "task-driven disciplinary development" fundamentally catalyzed the establishment of historical physical geography in China and significantly accelerated the modern transformation of Chinese historical geography. While domestic academia has robustly defended the legitimacy of historical physical geography through arguments addressing institutional structures, disciplinary alignment between geography and historical geography, essential differences between natural and human geography research paradigms, and the richness of Chinese historical archives, it remains undeniable that the disciplinary orientation that emerged in the 1950s directly adopted Soviet conceptual frameworks and theories. Furthermore, an academic approach that overlooks the practical realities of Soviet historical geography while seeking to ground the theoretical essence solely within the Chinese context necessitates potential revision and deeper exploration. This study examines the core theoretical contributions of Soviet historical geography during the same period. A comparative analysis of Sino-Soviet developments in historical physical geography reveals that China's "task-driven disciplinary development" model served as the practical foundation for its establishment. Despite direct conceptual influences from Soviet scholarship, Chinese historical physical geography has independently shaped its theoretical framework under specific historical conditions, largely achieving innovation and constructing an autonomous knowledge system, thereby advancing the discipline's comprehensive modernization. As a product of the Sino-Western intellectual synthesis, reconstructing the evolution of Chinese historical geography using a country-specific comparative approach holds significant methodological value in research on the geography of scientific knowledge.
This study aims to broaden the research scope of the history of geography in China. The materials used for the study included Harm J. de Blij's profile (CV), website, autobiography, geography textbooks, and research papers, as well as reviews and research from geography peers. De Blij is a contemporary geography master in political geography, geography textbooks, geography education, and scientific communication in geography. He is a representative of the systems theory school of political geography. He wrote several renowned geography textbooks, including System Political Geography, Human Geography: Culture, Society and Space, Geography: Realms, Regions and Concept, which acted as television precedents for geographical education. and also served as an editor for Journal of Geography and the founding editor of National Geographic Research. He is keen on geographic public speech and has popularized geographical knowledge and concepts. He is probably best known for being the geographic editor of the ABC TV program "Good Morning America" and his high-end science communication books The Power of Place and Why Geography Matters. Because of its innovative character, System Political Geography has scholarly and pedagogical impacts. Most political geography books at the time were dominated by chapters describing the circumstances of selected world regions or reviews of different attributes of states, such as population, resources, and environment. Harm's book encouraged thinking about the conceptual underpinnings of different ideas in political geography: the functional approach and the unified field theory. Second, Harm's book systematically examined particular historical developments of colonialism, the rise of the nation-state, and so on. Third, Harm's book included substantial excerpts from original papers. Human Geography: Culture, Society and Space and Geography: Realms, Regions and Concept are two popular textbooks in Harm's textbooks that act as an introduction to Human Geography and Geography. The Chinese edition of Human Geography: Culture, Society and Space was published by Beijing Normal University Press in 1988, and is considered an important teaching reference for human geography courses. Harm also made important contributions to scholarship on the role of geography in public debate, publishing pieces in the Annals of the Association of American Geographers and Progress in Human Geography and encouraging academic geographers to reach beyond the confines of the academy. Harm's lifelong thinking about political geography culminated in his book Why Geography Matters, which was revised and expanded several years later (de Blij 2012). Harm set a good example of high-quality geography textbooks based on academic research, actively spreading and promoting geography thinking, and writing popular science works and newspaper column articles based on hot issues from the perspective of geography. We can learn a lot from Harm J. de Blij on the main three aspects.
Investigations have revealed significant degradation of nearshore coral reef areas in the South China Sea in recent decades; thus, coral reef conservation is in urgent need of more scientific management insights. The health of coral reef ecosystems can be effectively assessed by utilizing the photosynthetic ecological parameters of zooxanthellae, which are symbiotic with scleractinian corals. In this study, six genera of scleractinian corals (Platygyra, Dipsastraea, Favites, Porites, Acropora, and Pavona) from Weizhou Island, Daya Bay, and Wanshan Archipelago in the northern part of the South China Sea were experimentally studied. Three physiological parameters, namely the density of coral symbiotic zooxanthellae, chlorophyll-a content, and photosynthetically effective quantum yield (Φ PSII), were measured to understand the photosynthetic characteristics of scleractinian coral symbionts in relatively high-latitude corals, compare their intergeneric differences among different coral morphologies, and explore the ecological effects of environmental factors by analyzing spatial similarities and differences. The study results are as follows: First, a one-way analysis of variance and non-parametric tests based on the division of individual coral distribution areas showed overall significant spatial differences in the density and chlorophyll-a content of scleractinian corals' zooxanthellae from the Weizhou Island and Daya Bay (P≤0.01); no significant spatial differences were observed in the physiological parameters of photosynthesis for those from the Daya Bay and Zhuhai's Wanshan Archipelago; Redundancy analysis(RDA) analyses indicated that Sea Surface Temperature(SST) was the most important environmental factor affecting the density and chlorophyll-a content of the coral symbiotic zooxanthellae. Due to its unique geographical location and environmental factors, the ecological status of coral communities in the Daya Bay is well-maintained with higher density and chlorophyll-a content of symbiotic zooxanthellae in the relatively high-latitude sea area. Second, the density and chlorophyll-a content of the zooxanthellae of Platygyra from the Daya Bay were significantly higher than those of Acropora and Pavona. Coral morphology may be a key driver influencing the relationship between density and photosynthesis of the symbiotic zooxanthellae. Massive corals generally had higher symbiotic zooxanthellae density and chlorophyll-a content and showed greater tolerance to thermal stress than branching corals. Under similar morphologies, significant interspecific differences in the density of symbiotic zooxanthellae in corals were also observed, which may be related to their unique skeletal structures and physiological characteristics. These findings reveal that the physiological responses of scleractinian corals and their symbiotic zooxanthellae to environmental changes are not fixed, and that coral morphology and interspecific differences have complex effects on their ecological adaptations.
Crown-of-Thorns Starfish (CoTS) are natural enemies of corals. Periodic outbreaks of CoTS and substantial feeding on corals lead to the degradation of coral reefs among the Indo-Pacific Ocean. Symbiotic bacteria play an important role in the development, reproduction, and digestion of CoTS. However, little is known about their composition and function. The pyloric ceca are the main digestive organ of CoTS. In this study, the composition and function of bacteria in the pyloric ceca of 15 adult A. solaris collected from the coral reef area of Xisha Islands were tested by high-throughput sequencing. A total of 833 bacterial OTUs were detected in the pyloric ceca, belonging to 26 phyla, 55 classes, 115 orders, 171 families, and 278 genera. The dominant phyla were Proteobacteria (94.50%), and the dominant genera were Vibrio (60.61%), Ralstonia (17.86%), and Photobacterium (6.64%). The symbiotic bacterial composition of other reef-associated organisms with different feeding habits, distributed in the Xisha Islands, were different. Composition of the pyloric cecal bacteria of CoTS were relatively similar to that of the coral symbiotic bacteria owing to the presence of some same bacteria genera in microbiome. Moreover, Vibrio was the dominant bacteria in both the pyloric cecal bacteria of CoTS and symbiotic bacteria of bleached Acropora solitaryensis, indicating high similarity. Therefore, the feeding habit of corals might be the important factor that affects the bacterial composition of the pyloric ceca of CoTS. The bacterial composition of the digestive tract of CoTS from the Great Barrier Reef of Australia and Japan showed the presence of Vibrionales, Burkholderiales, Rhizobiales, and Bacillales. However, significant regional differences were observed between the bacterial composition of the Xisha Island and Great Barrier Reef of Australia or Japan. Vibrio was more abundant in samples from the Xisha Islands than those from the Great Barrier Reef and Japan. This might be related to the massive coral bleaching events in the Xisha Islands from 2020 to 2021, which increased the relative abundance of Vibrio among the symbiotic bacteria of bleached corals. Additionally, as a potential Vibrio transmission vector, CoTS can pose a threat to the coral reef ecosystem in South China Sea. The results of bacterial function predict that their genome function was mainly focused on metabolism. The pathways with high relative abundance included carbohydrate, amino acid, cofactors and vitamins, and lipid metabolism. These results suggest that pyloric cecal bacteria may be involved in the daily physiological metabolic processes of CoTS. Thus, they might help digest corals by secreting hydrolytic enzymes. This study revealed the community composition, diversity, and affecting factors (feeding on coral) of pyloric cecal bacteria in CoTS from Xisha Islands, South China Sea.
Coral reef systems are vital natural barriers that dissipate wave energy and protect coastlines. However, anthropogenic damage has severely compromised this protective function, necessitating restoration efforts such as submerged breakwaters. To understand the influence of discontinuous submerged breakwaters on wave hydrodynamics over reef flats, this study employed physical model experiments and numerical simulations. A series of irregular waves were tested under scenarios with and without a breakwater, systematically varying the key parameters: significant wave height, water depth over the breakwater crown, spectral peak period, and gap width. The results demonstrate that discontinuous submerged breakwaters reduce the hydrodynamic loads on reef flats by generating wave reflection and refraction, as well as by enhancing the viscous dissipation of rip currents at discontinuities with incident waves. Specifically, breakwaters reduce the infragravity wave energy and wave heights, wave-induced set-up on the reef flat, and maximum wave run-up on the back reef slope. The reduction in wave run-up and reef flat set-up is most significant under minimal significant wave height conditions. Increasing the water depth over the breakwater crown can lead to incomplete wave breaking, thereby causing a relative increase in the contribution of short waves to the total wave run-up. Increasing the gap width enhances the effectiveness of the breakwater in reducing both the run-up and set-up, while simultaneously weakening the resonance amplification of infragravity waves on the reef flat. Conversely, increasing the spectral peak period intensifies infragravity wave resonance. Finally, the complex hydrodynamics along the reef are revealed using the waves2Foam model in OpenFOAM to construct a three-dimensional numerical wave flume. The study found that abrupt rip currents are generated at the discontinuities of submerged breakwaters while simultaneously reducing the onshore flow velocity over the reef flat. In conclusion, discontinuous submerged breakwaters are a viable engineering measure for mitigating coastal hazards in degraded reefs by reducing damage to infragravity waves, wave set-ups, and wave run-ups. These findings provide essential mechanistic insights and quantitative guidance for designing effective reef restoration and protection structures that incorporate submerged breakwaters.
In this study, the variation law of nonlinear characteristic parameters of waves near islands and reefs with different slopes was examined through physical model tests. The main conclusions are as follows: (1) When a regular wave propagates to the shallow water area of the first reef flat, the peak becomes steep, the trough becomes flat, and the wave surface presents a shape similar to an elliptical cosine wave. The wave shallowing deformation near the reef flat steps reaches the limit, the amplitude increases significantly, and the front surface of the wave peak becomes steep and gradually asymmetric. The wave breaks on the second reef flat, the wave energy transfers from the main wave frequency to the high frequency, the traveling wave is regenerated, and an obvious secondary wave peak appears. (2) In the process of wave propagation from the far-sea end to the vicinity of the reef edge, because of the shallowing deformation, high-order constrained harmonics are generated, which makes the wave surface asymmetric along the horizontal axis and vertical axis. The amplitude of the wave skewness, asymmetry, and peak of the Usser number reaches a maximum near the reef flat step and then decreases rapidly on the second reef flat. The wave surface gradually approaches symmetry in the direction of the horizontal axis and the vertical axis. The amplitudes of the three nonlinear characteristic parameters increases with the increase in incident wave height and wave period and decreases with the increase in reef flat water depth. (3) When the nonlinearity of the incident wave is stronger, the asymmetry and skewness are larger. As the Eser number increased, the wave skewness showed a positive correlation with the increasing trend, while the asymmetry showed a negative correlation with the decreasing trend. A certain correlation was observed between the wave skewness and asymmetry on the reef flat with different slope and the local Ursell number. Based on this result, this study proposes a set of empirical formulas for wave skewness and asymmetry parameters on reef flat with different slope angle.This study enriches the hydrodynamic theory of complex coral reef coasts and lays a foundation for further research on the ecological environment protection and coastal evolution mechanism in the sea area near coral reefs. However, this study only discusses the variation law of wave nonlinear characteristic parameters near islands and reefs with different slopes under the influence of wave factor changes. In the future, the influence of differences of island topography on wave nonlinearity should be studied in greater detail.
The accelerated promotion of new urbanization has brought about population mobility, which has placed greater pressure on megacities in terms of inter-regional competition for high-quality resources in compulsory education and their carrying capacity. To achieve high-quality and balanced development of compulsory education, it is not only necessary to achieve a balanced allocation of resources in terms of quantity and structure, but also to pay attention to the spatial balanced distribution of quality. This study uses Wuhan, a central Chinese megacity, as a case. Integrating Point of Interest data of primary and secondary schools, educational resources, road network information, this study uses GIS methodologies, such as the nearest neighbor index, coefficient of variation, kernel density analysis, service area network analysis, and an improved 2SFCA method to evaluate the spatial distribution characteristics of compulsory education resources in Wuhan and the accessibility and resource distribution equilibrium across districts. In terms of spatial quantity equilibrium, although the distribution of primary and secondary schools in Wuhan's districts is relatively uniform, the resource density is biased towards the central urban areas and shows a single-center clustering, resulting in sparse resource distribution in the remote urban areas. In terms of spatial structural equilibrium, considering students' commuting modes, time cost and the matching of supply and demand, primary schools exhibit better accessibility and resource equilibrium than junior high schools. In terms of spatial quality equilibrium, the human, material, and financial resource allocation equilibrium of primary schools is generally better than that of junior high schools, and both primary and junior high schools in the remote urban areas are less balanced than those in the central urban areas. This imbalance in resource distribution is in conflict with the population expansion and uneven distribution in the urbanization process of Wuhan. Therefore, it is suggested that the future layout for compulsory education in Wuhan should be combined with regional functions, population size, and educational needs to strengthen the forward-looking allocation of educational resources and land use planning in the remote urban areas, optimize the educational layout of functional areas to adapt to population growth and enhance accessibility, and build a balanced system of teacher resource allocation to promote the high-quality and integrated development of compulsory education. This study builds a spatial analysis framework based on a three-dimensional perspective of 'quantity-structure-quality', which expands the research perspective of high-quality and equilibrium allocation of compulsory education resources, and the spatial accessibility analysis from the perspective of supply and demand provides methodological references for other megacities to optimize the layout and resource allocation of primary and secondary schools in different regions, and also enhances the understanding of the differentiated layout of compulsory education resources in different administrative districts of megacities.
With the increasing integration of urban public transportation modes, the demand for first- and last-mile travel has become an urgent issue. Owing to its convenience and affordability, bike-sharing has been recognized as an effective solution for addressing this need. To better understand the demand for intermodal trips involving bike-sharing and conventional buses, this study focuses on the spatial heterogeneity of such trips. A method based on bike-sharing density was proposed to identify intermodal trips near bus stops. The spatial distribution of these trips was then analyzed. Geographically Weighted Regression and Multiscale Geographically Weighted Regression models were employed to examine the effects of land use, population, socioeconomic attributes, transportation environment, and destination accessibility on intermodal trip demand. Spatial variations in these effects were also assessed. The results indicated that the density of bike-sharing trips near bus stops followed a consistent pattern. The density decreases with increasing distance from the stop, and the rate of decline exhibits a "U-shaped" pattern. A buffer radius of 50 m was identified as the optimal threshold at which the rate of decrease was minimized. Trips within this radius accounted for approximately 17.1% of all bike-sharing trips. In Shenzhen, intermodal trips were primarily concentrated in southern Longhua, western Luohu, Futian, and central Nanshan. Secondary concentrations were observed in Guangming and Bao'an districts. The spatial distributions of trip origins and destinations showed minimal differences, indicating a relatively balanced distribution. This distribution aligns with the overall pattern of bike-sharing activities. The explanatory variables exhibited significant spatial heterogeneity in their effects on intermodal trip demand. Shopping facilities, hotel accommodations, cultural and educational institutions, GDP, and distance to the city center were found to have positive effects. Among these, the influence of shopping facilities was particularly notable in the central areas, with weekdays' coefficients concentrated around 0.057 and more dispersed on weekends. The impact of hotel accommodations was dispersed across weekdays and weekends. Cultural and educational facilities had a weekday coefficient concentration of approximately 0.098, whereas the weekend effects were more scattered. GDP demonstrated the highest positive influence among all variables, with coefficients of 0.176 on weekdays and 0.150 on weekends. The coefficients for distance to the city center were relatively concentrated at 0.110 and 0.233 on weekdays and weekends, respectively. By contrast, residential land-use density, road network density, and stop proximity exhibited inhibitory effects. Coefficients for residential land-use density were -0.020 on weekdays and -0.018 on weekends. Road network density showed coefficients of -0.020 and -0.010, respectively. The effect of stop proximity varied more spatially. Additionally, tourist attractions have time-sensitive effects, suppressing intermodal trip demand on weekdays and promoting demand on weekends. It is suggested that designated bike-sharing parking zones be established within a 50 m radius of bus stops to reduce the transfer walking distance. On weekdays, more bikes should be deployed near schools and residential areas; on weekends, the deployment should focus on scenic areas and bookstores. These findings help to delineate the effective spatial scope of intermodal trips and reveal how various built environments and socioeconomic factors shape trip patterns. The results offer practical insights for improving the coordination between bike-sharing and conventional buses, enhancing the overall efficiency of public transport and increasing its appeal to commuters.
Bike-sharing has emerged as a crucial mode of short-distance transportation for urban residents due to its flexibility, convenience, and affordability. This paper analyzes the spatiotemporal data of bike-sharing in the central urban area of Shenzhen to explore usage patterns and characteristics, with the aim of optimizing bike-sharing system management and scheduling. Initially, we used statistical methods to conduct an exploratory analysis of the data, uncovering the temporal, spatial, and Origin-Destination (OD) flow characteristics of urban cycling. Following this, we applied a tensor decomposition model to the spatiotemporal correlation characteristics of bike-sharing data, enhancing our understanding of the spatiotemporal cycling patterns of residents in central Shenzhen. Bike-sharing usage in Shenzhen displays significant spatiotemporal patterns, with high-frequency usage areas on both weekdays and weekends concentrated in the mid-southern part of the Nanshan District, southeastern part of the Futian District, and southwestern part of the Luohu District. Notably, on weekdays, two distinct morning peaks were observed in bike usage, indicating a more diverse spatial travel pattern. During morning peak hours, bike usage is primarily concentrated in residential and commercial areas, while during off-peak hours, it shifts to areas around recreational facilities. By integrating the initial statistical analysis with tensor decomposition, we constructed a comprehensive model of bike-sharing usage that accounts for variations across different days of the week and times of the day. This model helps identify the most significant OD flows and their interactions over time and space. We also incorporated Points of Interest data to better understand the potential travel purposes of bike-sharing users, linking high-usage areas with specific types of destinations, such as business districts, educational institutions, and recreational areas. The findings of this study have important implications for urban planners and bike-sharing operators. The clear identification of high-usage areas and peak times can inform more efficient bike redistribution strategies, ensuring that bikes are available where and when they are most needed. Moreover, understanding the dynamic nature of bike-sharing usage patterns can aid in designing better infrastructure, such as dedicated bike lanes and improved parking facilities, that cater to the needs of bike-sharing users. Our research also contributes to the broader field of urban mobility studies by demonstrating the effectiveness of tensor decomposition in analyzing complex spatiotemporal data. Unlike traditional methods that may treat time and space independently, tensor decomposition allows for a more integrated approach, capturing the interactions between different dimensions of data. This provides a richer, more nuanced understanding of urban mobility patterns. Future research will aim to integrate other transportation datasets, such as public transit and ride-hailing services, to provide a more comprehensive view of urban mobility and further enhance the understanding of population flow dynamics in high-density urban environments.
Using images and interview data from the Nanzhi Street in the Songyang County, combined with K.-S. Lee's five-dimensional theory of food memory, this study explores the impact of media and commercialization on traditional food and local memory. This work analyzes how five factors—population hollowing, commercialization of preparation methods, standardization of sensory experiences, weakening of emotional connections, and uniformity—affect the relationship between food and local memory. It also discusses the mediating role of media as an intermediary factor. The findings indicate: (1) Loss of native residents: The departure of native residents has led to external operators maintaining emotional ties but failing to restore the community atmosphere. The demographic shift in the Nanzhi Street has transformed local memory from the emotional memory of native residents to the commercial memory of external operators. Media has simultaneously enhanced commercial vitality and accelerated the commodification and symbolization of local memory; (2) Differences in shop styles: There is a clear distinction between the styles of registered and non-registered shops. Registered shops preserve local characteristics but tend toward symbolic traditional appearances under policy support and media influence, while non-registered shops cater to influencer-driven culture, leaning towards commercialization. This dual influence maintains commercial vitality but also speeds up the commodification of local memory, reflecting the tension between preserving local culture and pursuing commercial development; (3) Changes in traditional food and sensory experiences: The preparation methods and sensory experiences of traditional food have changed to meet consumer demands, leading to differences in how tourists and locals perceive local memory. Media's simplified narratives and excessive commercialization reduce the cultural depth of local cuisine, reinforce stereotypes, and overlook the importance of craftsmanship and deep-rooted culture. These shifts not only affect consumer perceptions but also undermine the authenticity and completeness of local memory. Additionally, under the influence of commerce and media, traditional food has become increasingly standardized, with weakened artisanal techniques and local characteristics. Younger consumers are more exposed to adapted, standardized flavors, further simplifying the cultural essence of local cuisine and diminishing its role in cultural diversity and regional identity; (4) Impact of media on emotional connections: Media's influence on emotional connections is dual-faceted. For locals, private memories are made public, transforming traditional food from a familial emotional symbol into a symbol of local culture. For tourists, media transforms local memory into a commodified and emotionalized product, replacing personal connections with consumer-driven experiences. This shift reflects the commercialization of local memory and highlights the disconnect in emotional ties between locals and tourists, as private memories are gradually replaced by mass-consumption emotions. The work reveals the conflict between commercialization and local characteristics in the Nanzhi Street under media and policy guidance, emphasizing the importance of preserving local memory and emotional connections during urban transformation.
Analysis of the spatiotemporal agglomeration trends of individuals' daily activities can contribute to gaining a better understanding of the temporal and spatial selection characteristics of residents' daily activities, and the utilization of urban space. This is of considerable practical significance for improving the living environment and enhancing the quality of life of residents in affordable housing in the context of the current era of optimizing existing stock. In this study. we examined a large-scale affordable residential area in Nanjing as an empirical case. Based on the perspective of "family division of labor" and the activity log data of the residents in the large-scale affordable residential area, we initially applied a spatial autocorrelation model to construct a spatiotemporal autocorrelation function, and depicted the overall characteristics of the spatiotemporal agglomeration of the daily activities of the residents in this area from the dual scales of "main urban area–residential area." In addition, we conducted a comparative analysis of the spatiotemporal agglomeration characteristics of different activities. In this context, we characterized and compared the spatiotemporal response patterns of the daily activities of residents in this type of residential area. We subsequently undertook theoretical derivation, interpretation and refinement of the temporal and spatial selection processes of the daily activities of residents in large-scale guaranteed residential areas. From the perspective of spatiotemporal agglomeration trends, our findings revealed that the spatial and temporal clustering of the daily activities of residents in large low-income residential areas is often closely associated with the intensity of family division of labor and spatial scale. Among these, the spatial and temporal clustering of daily activities under medium and high intensity division of household labor was observed to be more obvious at the main urban area scale, whereas daily activities under low and medium intensity division of household labor were more concentrated on the scale of residential areas. From the perspective of response mode, we detected clear difference between the temporal-family and spatial-family response patterns of all types of activities, particularly between work and non-work activities. From the perspective of the interpretive model, the temporal range of different activities can be ordered as maintenance activities > survival activities > free activities, and the interaction of the temporal response process mainly occurs between the medium- and high-intensity division of household labor. Moreover, the spatial scope of different activities can generally be ordered as survival activities > maintenance activities > free activities, and the interaction of the spatial response process is mainly reflected in the high-intensity division of household labor. By examining the spatiotemporal patterns and decision-making mechanisms of residents' daily activities. we can provide necessary guidance and a basis for the construction of an ideal living circle for residents in large-scale public welfare residential areas.
