New infrastructure is not only the cornerstone of the fourth industrial revolution, the engine for the high-quality development of regional economy and the rise of a great nation, but also the frontier and important research field of economic geography. From the perspective beyond technology, this paper systematically combs the relevant theories about new infrastructure in current economic geography, including the theory of technological relatedness, the theory of key enabling technology, the theory of technology-system co-evolution and the theory of regional integration. On this basis, 3 scientific issues and research ideas that need to be focused on are proposed, namely, the research on the path and mechanism of the new infrastructure technology-system collaborative evolution, the research on the innovation and development mechanism of the new infrastructure enabling industry, and the research on the overall layout of the new infrastructure and the operation mechanism of regional integration. This paper aims to establish a theoretical framework for new infrastructure to promote regional economic development, in order to provide theoretical support for China to better play the strategic potential of new infrastructure and promote regional high-quality development.

Based on the panel data of 31 provinces (cities and districts) in China from 2013 to 2020, this paper measures the level of new infrastructure development and the degree of coordinated regional economic development in each province and then uses the coupling coordination model to measure the coupling coordination degree of the two and analyzes their spatial and temporal evolution patterns and influencing factors. The results show that: 1) The level of development in China’s new infrastructure and regional economic coordination degree has been improving each year, with increasing coupling and coordination between the two. Despite starting from a lower level, the growth rate of new infrastructure has been significant since 2018, reaching 29.96% in 2020. Similarly, there has been a noticeable upward trend in the degree of regional economic coordination and the coupling between new infrastructure and regional economic coordination degree. 2) The coupling and coordination between new infrastructure and regional economic coordination degree exhibit spatial heterogeneity, with the eastern region surpassing the central and northeastern regions, while the western region lags behind. This discrepancy can be attributed to the relatively higher levels of new infrastructure development and regional economic coordination degree in the eastern provinces, as well as the smaller internal differences within the central and northeastern provinces. On the other hand, the western provinces exhibit greater disparities. 3) The level of new infrastructure development demonstrates negative spatial spillover effects among provincial regions, whereas the degree of regional economic coordination and the coupling between new infrastructure and regional economic coordination degree exhibit positive spatial spillover effects among provincial regions. 4) The factors that primarily influence the coupling and coordination between new infrastructure and regional economic coordination degree are related to industrial structure and urbanization processes. Conversely, factors such as government management and population density have less discernible effects on this coupling and coordination. The article investigates the evolutionary characteristics and influencing factors of the level of new infrastructure development, the degree of coordinated regional economic development, and the degree of coupling and coordination of the two in China, and expects to provide a reference for decision-making on the benign interaction between new infrastructure and coordinated regional economic development in China.

The supply and demand allocation and logistics optimization of emergency materials are important support for emergency materials management and decision-makings. This study proposes a supply-demand analysis based material supply point allocation method, which on the basis of the optimal supply and demand allocation model. This method takes into account the constraint condition that the market reserve point must simultaneously supply both the affected and original demand points with supportive materials. Compared to traditional methods, this approach further improves the rationality and accuracy of material supply and demand analysis. Based on the allocation of material supply points, a method for optimizing the emergency material distribution path under flood scenarios is further developed. This method is based on real road networks, using “Degree” “Squares Clustering Coefficient” and “Road Design Daily Traffic Volume” to evaluate the reliability of road sections, and fully considers the impact of the flood disaster on the road travel time. It aims to achieve the shortest path travel time and the highest path reliability, using heuristic algorithms to solve the optimal path. A case study was conducted in Fengxian District, Shanghai, China. Through comparative analysis of multiple scheme scenarios of collaborative supply between the market and government, it was found that the G scheme (100% government supply) required a longer distribution time and resulted in a higher overall time cost, which could lead to the timeout situation for emergency response missions. The S plan (100% market supply) had a lower delivery efficiency and was prone to waste of human and transportation resources. However, the S1500 scheme (the market supplies the shelters within the 1 500 m coverage range and the government supplies the remaining shelters) was a collaborative supply scheme that was suitable for all 3 types of materials (water, rice, milk (infant formula)) in the case study. The research results can provide decision supporting for emergency rescue and relief efforts of relevant departments in the study area. The methods proposed in this paper can provide methodological references for related studies in other regions.

The new waves of information technology revolution give rise to digital infrastructure exemplified by 5G base stations, big data centers, and industrial internet, constituting strategic components of the modern infrastructure system. Proliferated studies on digital infrastructure range from diverse disciplines and perspectives. Given the unclear principal line of research progress in geographical studies on digital infrastructure, along with ambiguous disciplinary contribution and future research avenues, this paper therefore seeks to review and compare research progress on digital infrastructure from a geographical perspective in China and abroad, and to draw upon key research agendas for academic attention. In general, overseas studies have an early start, with rapid research progress and diversified themes, and have been consistently intensified and widened. By contrast, domestic studies exhibit a late start but have increased explosively since 2019 mainly by scholars in the field of economics and management. Based on a critical perspective and demand side, overseas studies pay much attention to the digital gap, socio-spatial inequality, and digital transformation of disadvantaged regions. Domestic studies, which place more emphasis on a functional perspective and supply side, focus on how digital infrastructure empowers regional digital economic development and connectivity within and among regions. In short, the new waves of digital technology revolution, justice and equity requirements in the information society, and national strategic demands facilitate the rise and development of digital infrastructure studies in geography. Although overseas and domestic studies share similar themes, but they exhibit different priorities. Knowledge production and theoretical construction of digital infrastructure in China by geographers are still in its infancy. Looking forward, this paper suggests that: 1) geographical studies on digital infrastructure in China should balance the supply and demand sides, in order to strengthen the interaction and systematization of research achievements; 2) digital infrastructure needs to be better incorporated into related theoretical frameworks in geography, deepening disciplinary knowledge production and theoretical contribution; 3) comprehensiveness of geography should be sufficiently employed as an advantaged way to lead multi-disciplinary studies on digital infrastructure.

Scientific and technological innovations is the primary driving forces for economic development in society. In the context of the new scientific and technological revolution and industrial transformation, major countries and regions are experiencing increasingly fierce competition and strategic games in science and technology. Consequently, scientific and technological innovation has become a crucial means for nations worldwide to enhance their core competitiveness and navigate through these epochal changes. Enterprises constitute the principal agents of scientific and technological innovation, functioning both as the orchestrators and active participants in this arena. Notably, enterprises with significant investment in research and development (R&D)—characterized by substantial scale and intensive R&D activities—have ascended as the central drivers of scientific and technological advancement in China. This paper employs regional spatial analysis and qualitative comparative analysis (QCA) to empirically investigate the spatiotemporal patterns and industrial characteristics of R&D-intensive enterprises in China. Furthermore, it delves into the formation mechanisms of these enterprises using QCA. Firstly, the study reveals that China’s R&D-intensive enterprises are increasingly expanding into the central and western regions of China, exacerbating regional development disparities. Concurrently, the Beijing-Tianjin-Hebei urban agglomeration, the Yangtze River Delta, and the Guangdong-Hong Kong-Macao Greater Bay Area have emerged as the principal spatial hubs for enterprise innovation. Secondly, the analysis indicates a marked differentiation in the industrial development of R&D-intensive enterprises, with the Information and Communication Technology (ICT) sector emerging as the pivotal area of focus. Moreover, distinct science and technology innovation regions in China have developed differentiated industry strengths, exhibiting a pronounced regional division of labor. Thirdly, the spatial agglomeration of enterprises is identified as the outcome of a multi-condition configuration effect. This effect arises from the synergistic integration of various factors, leading to 4 distinct clustering paths: economy-led government services, innovation environment-driven development, government-guided university-industry-environment incubation, and talent-led innovation ecosystem optimization. These strategies underscore the importance of leveraging comprehensive advantages to foster an optimal innovation and entrepreneurship ecosystem. They advocate for prioritizing economic leadership to enhance the innovation and entrepreneurship environment, for empowering the government’s pivotal role to boost the city’s innovative dynamics, and for amplifying the central influence of talent to cultivate an inclusive innovation atmosphere. Collectively, these approaches facilitate the spatial agglomeration of enterprises.

Narrowing the gap in sharing development achievements is an inevitable requirement for achieving the goal of “common prosperity”, and the rise of the digital economy has become an important measure to narrow the gap in sharing development achievements. Analyzing the relationship between the two is beneficial for the government to explore and formulate targeted policies to help narrow the gap in sharing development achievements through the digital economy, and promote high-quality economic development. This article first analyzes the impact mechanism of digital economy (digital industrialization, industrial digitization) on the gap in sharing development achievements from the perspectives of development achievement speed, development achievement quality, development achievement benefits, development achievement structure, and collaborative integration. Subsequently, the entropy method was used to synthesize the three sub dimensions of population gap, regional gap, and urban-rural gap to obtain the development achievement sharing gap, and the digital economy (digital industrialization, industrial digitization) was quantified within the framework of the digital production function. Finally, using panel data models and panel threshold models, this study empirically examines the impact characteristics of digital industrialization, industrial digitization, and their synergistic integration on the gap in sharing development achievements, and explores the differences in the impact of digital economy in different regions. The research results indicate that digital industrialization has a narrowing effect on the gap in sharing development achievements, while industrial digitization has a widening effect. Compared to digital industrialization, the synergistic effect of the two is not significant. There is an inverted U-shaped relationship between digital industrialization, industrial digitization, and the gap in sharing development achievements. There is regional heterogeneity in the impact of digital industrialization and industrial digitization. Digital industrialization has not had a narrowing effect on the eastern region, while industrial digitization has a significantly higher effect on widening the sharing gap between the central and western regions than the eastern region; When the sharing gap is low, the narrowing effect of digital industrialization is relatively small, while when the sharing gap is large, the widening effect of industrial digitization is relatively high. There is a clear interactive relationship between digital industrialization and industrial digitization. The narrowing effect of digital industrialization first increases and then decreases with the improvement of industrial digitization level, while the widening effect of industrial digitization changes into a narrowing effect with the improvement of digital industrialization level.

Air traffic flow network has gradually become a focus topic and core matter of high attention in academic and decision-making fields. At present, the research of air traffic flow network is faced with a major challenge of the detection of interactive air traffic flow. This paper intends to construct a methodological framework for the structural resolution of air traffic flow network of “big-channel-in-the-sky” and apply it to the Beijing–Kunming, Guangzhou–Lanzhou and Shanghai–Lanzhou channels to find out the key constraints of air traffic flow operation. The results are as follows. The absorption effect of air traffic flow delay in the “big-channel-in-the-sky” is obvious. The operating efficiency, distance efficiency and time efficiency in the en route phase are higher than those in the departure/arrival phase, which is mainly due to the flight path differentiation and air traffic flow adjustment in the en route phase. It is quite different from the delay accumulation phenomenon in air maintenance phase identified previously based on the delay cost of air corridor. The construction of the “big-channel-in-the-sky” has greatly changed the obstacles in the shared segment or flight range, and greatly optimized the air traffic flow capacity, indicating that the air traffic flow in the “big-channel-in-the-sky” has the characteristics of flexible. However, the overall air traffic flow performance of different channels, the change of high-density airspace expansion and contraction, and the phase transformation of air traffic flow under airspace capacity limitation also show personalized differences. The Guangzhou–Lanzhou channel has the most typical characteristics of balanced use of airspace. The location and range of the high-density airspace in Beijing–Kunming channel are relatively stable, while the Guangzhou–Lanzhou and Shanghai–Lanzhou channels show the characteristics of variable range and linear decline, respectively, which results in the differential distribution of intra-day congestion phase under the condition of limited airspace capacity. The above differences are caused by the participation of intra-day air traffic flow and its stability, and the convergence degree of go up and go down flight paths. This research shows that the structural resolution of air traffic flow network is a basic work to fully understand the function of airspace system. The analysis of ATFN structural is a prerequisite to solve the problem of efficient utilization of airspace resources and promote the dynamic transformation of airspace organization form, especially in the field of airspace strategic planning.

Under the confluence of economic advancement and ecological preservation imperatives, the imperative to enhance energy efficiency has crystallized as a pivotal metric encapsulating a nation’s developmental prowess. This research delves into the intricate spatial and temporal dynamics, as well as the underlying determinants, of urban energy efficiency within the Yellow River Basin spanning the years 2007 to 2018. Employing a multifaceted analytical approach comprising the non-parametric super-SBM model, geographic information system spatial analysis, panel Tobit regression, and geographically weighted regression (GWR) model, this study unravels compelling insights. Firstly, it elucidates the trajectory of urban comprehensive energy efficiency over the study duration, revealing a nuanced narrative of relative stability juxtaposed with a discernible downward trajectory. Moreover, the study unearths a trend of diminishing regional differentials in efficiency distribution, accompanied by the emergence of a conspicuous patchy distribution paradigm. Notably, cities situated upstream evinced tendencies towards lower and medium-low efficiency levels, in stark contrast to their midstream and downstream counterparts, which predominantly exhibited medium-low to medium-high efficiency ranges. Furthermore, the Tobit regression analyses illuminate the pivotal role played by economic development levels and green innovation in bolstering urban comprehensive energy efficiency, underscored by their significant positive impacts. Conversely, the deleterious effects of carbon emissions, industrial structure, and environmental regulations manifest as significant negative influencers on urban comprehensive energy efficiency. Importantly, the findings from regional heterogeneity regression lend credence to the consistency of these discerned impacts across diverse geographical locales within the Yellow River Basin. Additionally, the application of geographically weighted regression (GWR) unfurls a tapestry of spatial heterogeneity in the influence exerted by various factors, thus delineating distinct distribution patterns across the study area. These nuanced insights proffer valuable guidance for tailoring targeted interventions aimed at fortifying urban comprehensive energy efficiency within the Yellow River Basin, thereby fostering sustainable developmental trajectories. Through this comprehensive elucidation, the research augments our understanding of the complex interplay between economic imperatives, environmental considerations, and the imperative of energy efficiency enhancement, thereby paving the path for informed policy formulation and implementation endeavors.

HSR, as an important channel running through cities and regions, the network and externalities make it present multi-dimensional spatial scale properties, but the existing studies lack a systematic analysis of the multi-dimensional spatial effects of high-speed railway. In view of this, based on the scale attributes of the multi-dimensional space of the high-speed railway, from the 3 scales of the city interior, the city boundary, and the cross-urban area, by modifying the traditional accessibility evaluation model, this article constructs accessibility evaluation methods under different scale conditions, and systematically measures the comprehensive spatial impact of high-speed railway on urban regional development. Results found that: 1) At present, “one city with multiple stations” has become a common mode of spatial organiza tion of high-speed railway stations in cities in the Yangtze River Delta. Suburbs and central urban areas will be more closely connected through high-speed rail, and the development trend of melt city in the era of high-speed railway transit will be more obvious. Especially for Zhejiang Province, high-speed railway has become a key link between the inner suburbs of the city and the central city. 2) High-speed railway has become a key link and bridge for the reorganization of production and life interactions between adjacent cities. However, from the perspect of the spatial distribution pattern of the accessibility index on the neighboring scale, the development pattern of urban integration has obvious spatial heterogeneity characteristics. At present, 7 regions with a high level of urban integration have been initially formed, and basically around the important central and hub cities of the Yangtze River Delta (Shanghai, Nanjing, Hangzhou, Wenzhou, Hefei, Xuzhou, Wuxi). 3) High-speed railway has obvious advantages in medium- and long-distance transportation, which makes its impact on the development of regional integration even greater. Under the influence of high-speed railway, the integration pattern of the Yangtze River Delta presents a clear and obvious “Z” pattern, and it has clearly extended to Hefei.However, the degree of participation of surrounding cities in regional integration development is still relatively low.

Different from the economic globalization, led and promoted by developed countries in the past, China’s “Belt and Road” Initiative, adhering to the advanced concept of a community with a shared future for mankind, not only provides more opportunities for more developing countries to integrate into the global value chain division of labor, but also strives to improve its division of labor. Compared with existing literature, the marginal contribution of this article may lie in. First, from a research perspective, this article evaluates the practical effects of the “Belt and Road” Initiative from the specific perspective of “inclusive openness”. Second, in terms of indicators of selection, this article selects the Human Development Index (HDI) as an indicator to measure the possible inclusive opening effect of the “Belt and Road” Initiative in the countries along the route at the comprehensive and sub-index levels. Third, in terms of mechanism analysis, this article strives to discuss the unique mechanism and role of the “Belt and Road” Initiative in promoting the participation of countries along the route in the international division of labor, and then clarifies its mechanisms for inclusive openness. Fourth, in terms of research methods, considering that the countries along the route participate in the “Belt and Road” Initiative at different times, this article adopts the multi-period double difference method to improve the accuracy of policy processing time points. On the basis of theoretical analysis, using HDI as a characterization variable of the inclusive opening effect, based on the empirical data of 60 countries in the ADBMRIO database from 2010 to 2019, the empirical analysis of the double difference model and various robustness. The test results show that the “Belt and Road” Initiative has indeed significantly promoted the HDI of the countries along the route, showing a relatively inclusive opening feature. And the above-mentioned effects are mainly through the two mechanisms of increasing the participation of countries along the route in the global value chain and improving the status of the division of labor. Theoretical hypotheses are well tested for logical consistency metrics. It can be seen that the “Belt and Road” Initiative, which upholds the advanced concept of a community with a shared future for mankind, not only has a solid theoretical foundation, but also practical experience proves that China is already on the way to promote inclusive opening up.

Exploring the complex relationship between urban resilience and the carrying capacity of the tourism environment is of great significance in promoting efficient urbanization and highlighting the green development effects of tourism. This study focuses on the Yangtze River Economic Belt as the research object. It constructs a comprehensive evaluation index system for urban resilience and the carrying capacity of the tourism environment and measures their development levels. It uses a dual-index function to verify the interactive stress effect, employs the Haken model to measure the coordinated development trend, and utilizes the VAR model to assess the interactive response relationships. The results show that: 1) The overall level of urban resilience and the carrying capacity of the tourism environment in the Yangtze River Economic Belt have improved, with the eastern region taking the lead and the central and western regions catching up with the east, but there are still challenges of low-level convergence and insufficient urban resilience. 2) The interactive stress relationship is confirmed, indicating that there is a mutual stress effect between the level of urban resilience and the carrying capacity of the tourism environment in the Yangtze River Economic Belt, and there is temporal and spatial heterogeneity. The higher the level of urban resilience, the greater the pressure on the carrying capacity of the tourism environment, which shows a certain consistency between the two. 3) The regional collaborative level shows a favorable trend of transitioning from imbalance to synergy in the temporal dimension, with a decrease in mismatched areas and a continuous increase in high-quality collaborative areas. The spatial differentiation features evolve dynamically from “the eastern Yangtze River Economic Belt leadership” to “western Yangtze River Economic Belt rise” and then to “central Yangtze River Economic Belt catch-up”, with an enhanced trend of steady-state equilibrium convergence. 4) There are significant differences in regional impulse responses, with Jiangsu and Shanghai showing large fluctuations in the impact on urban resilience and the carrying capacity of the tourism environment. The impulse responses of the two systems in the central region exhibit the characteristic of “initial fluctuation followed by stability”, while the impulse responses of the two systems in the western region display more prominent fluctuations.

The relationship between urban area and green space area development is a key issue affecting the quality improvement of new urbanization in cities. Taking the Yangtze River Delta (YRD) region as the study area, we use the allometric growth model and the coupling coordination model to explore the development relationship between urban area and green space area from 2000 to 2020, and extract the interaction law and influencing factors of urban area-green space area allometric growth and coupling coordination. The results show that: 1) The urban area and green space area of the YRD exhibit the spatial structure of ‘one pole and many cores’, and it is highly stable in structure. Temporally, the allometric relationship type evolves with weak green space expansion-basic coordination between urban area and green space-weak green space expansion, while spatially, the number of cities with weak green space expansion type, i.e., positive allometric growth type, dominates. 2) The overall trend of coordination between urban area and green space in the YRD is increasing, and the pattern of coordination has strong stability, with a spatial distribution pattern of ‘high in the east and low in the west’, and the spatial difference of coordination is expanding. 3) The quantitative structure of coordination types between urban area and green space area in the YRD has changed from ‘pyramidal’, which gradually decreases with increasing coordination, to ‘olive’, which has the largest number of cities with medium levels of coordination. The coordination degree of positive allometric growth cities tends to rise with large spatial differences, while the coordination degree of negative allometric growth cities tends to fall with large spatial differences. 4) The urbanization rate, GDP per capita and population density affect the coupling coordination degree strongly, while the proportion of tertiary industry, fixed asset investment rate and financial self-sufficiency rate have different degrees of influence on the coupling coordination degree and the allometric growth rate. All of the influence factor on the coupling coordination degree exceeds that of the allometric growth rate.

Based on the new development concept, this paper constructs a resilience measurement index system from 4 dimensions of “economy-society-ecology-engineering” and quantitatively evaluates the urban resilience of Nanjing from 2005 to 2019 by dimensions and stages using entropy value method. A dynamic simulation model of Nanjing’s urban resilience was constructed with the help of System Dynamics to predict the development level of Nanjing’s urban resilience from 2020 to 2035 in a long time series and to compare the development potential of different scenarios. The results show that the overall trend of Nanjing’s comprehensive resilience and sub-dimensional resilience fluctuates upward between 2005 and 2019. Compared with 2019, by 2035, Nanjing’s comprehensive resilience level will increase by 25.62%, 27.59%, 28.40%, 27.19% and 30.29% under the scenarios of natural state development, high population growth, rapid economic growth, ecological priority development and comprehensive and coordinated development, respectively. It can be seen that the comprehensive coordinated development scenario can maximize the improvement of Nanjing’s urban resilience level, and achieve strong resilience earliest, while other development scenarios will have varying degrees of negative effects on certain socio-economic indicators. Therefore, Nanjing should focus on the continuous optimization of the integrated and coordinated development path.

Based on regional resilience, the evaluation index system of regional sustainable development (RSD) resilience will be constructed, and the development of red tourism resources in the study area will be planned in a spatial pattern, which is conducive to reasonably promoting the development of red tourism resources, promoting regional sustainable development, and achieving mutual promotion and win-win results. In this study, 97 counties in the Former Central Soviet Area of Fujian, Jiangxi and Guangdong were taken as examples to build an evaluation index system of RSD resilience level from 4 aspects of ecological resilience, economic resilience, cultural resilience and social resilience, and to classify and identify the characteristics and categories of red tourism resources in the spatial dimension. The research results are as follows: 1) The RSD toughness system level in the study area is generally medium low toughness, showing the spatial distribution characteristics of “high in the middle, low around”. 2) The distribution of Red Brigade resources in the Former Central Soviet Area is obviously clustered, while a small part of them are scattered. According to their scale and influence, they can be divided into 5 cluster types: cluster V, cluster IV, cluster III, cluster II, and cluster I. 3) With the goal of achieving regional sustainable development and improving the overall level of RSD resilience system, among them, economic resilience is low, social resilience is medium, cultural resilience and ecological resilience are high. 4) Based on the concept of global tourism planning, after fully considering the county’s resilience level and the development status of red tourism resources, the spatial pattern of red tourism resources development of “three zones, two belts and two cores” is finally planned. The research is of great significance to improve the coordinated development level of RSD resilience system and red tourism resources and realize the sustainable development of the Former Central Soviet Area.

Wind is the prime power of soil wind erosion. The Weather Factor (WF) of the Revised Wind Erosion Equation (RWEQ) are the most widely used expressions of wind erosion climatic erosivity. Based on the actual situation of the study area, soil freezing factor (FD) was added into the Weather Factor (WF), and the modified WF was used to evaluate wind erosivity. By calculating the yearly variation of WF, WF in different seasons and WF in different months, the temporal and spatial distribution changes of WF were drawn. WF is performed using more than wind velocity, precipitation, temperature and snow cover series at 157 national meteorological stations in 1980—2016. The following conclusions were drawn: 1) WF value in the study area descended from 1980 to 1988, with an average annual descend rate of about 37.20 kg/m, and it was relatively stable from 1989 to 2016, with an average value of about 190.36 kg/m; 2) WF value in spring accounts for about 63% of the whole year, and WF decreased most significantly in spring, with an annual descend rate of 34.94 kg/m, while the annual descend rates in summer and autumn were 3.19 kg/m and 1.87 kg/m respectively. 3) On the spatial distribution, the high value area of average WF over years are mainly distributed in north 40°N of the midwestern Inner Mongolia, the eastern Xinjiang and the western Qinghai, and the low value areas were mainly distributed in the southern Xinjiang, the eastern Qinghai and the southeast of the study area.

In order to reveal the influence of dynamic crowd activities on urban flood risk, a flood risk assessment model for urban places, considering crowd activities, is established to analyze the changes of flood risk in different types of places under 4 time periods: day and night on weekdays and day and night on rest days. 4 typical communities in Futian District of Shenzhen are selected as examples. The results show that: 1) In addition to the hazard factor, frequent crowd activities also contribute to increased flood risk. The total weight of 3 indicators related to crowd activities is 0.31. 2) The flood risk varies significantly across different place types and exhibits dynamic changes with crowd activities. The average risk of living places is higher than all other places, with minmal fluctuation in 4 periods; the average risk of flooding in residential mixed places ranks second highest, and the risk in the evening hours is about 25% higher than that in the daytime; the average risks in commercial places, public service places, and office-related mixed places are also higher, especially during the daytime on weekdays; the risk in green leisure places is the lowest across all four periods. 3) There are significant differences in flood risk between living community and comprehensive community, living community is the sustained high-risk community, with the proportion of high-risk places over 40% in all 4 periods, particularly over 60% at night. Comprehensive community presents the characteristic that flood risk is higher during the daytime on weekdays compared to other periods, when the proportion of high-risk places is up to 54%.

Based on the trade-offs and synergistic relationship perspective, the relationships, spatial and temporal evolution, and geographic variations of PM_2.5 concentration and light rain events in the Loess Plateau were investigated from a long time series and a multi-level spatial scale from 1998 to 2017. The results show that: 1) The PM_2.5 concentration and light rain events in the Loess Plateau show a slight upward trend in the fluctuation of ‘three peaks and three valleys’ with a circle of 5 or 4 years; 2) The relationship between PM_2.5 concentration and light rain events is characterised by “process synergy + incremental trade-off”. In terms of process evolution, synergy is the dominant relationship between PM_2.5 concentration and light rain events in the Loess Plateau during the study period, but in terms of incremental changes based on tilt rate, the two are dominated by an anisotropic trade-off, indicating that the light rain events have been increasing in anisotropic direction. Trade-off relationship is dominant, suggesting that the enhancement of light rain events is important in the future haze management in the Loess Plateau; 3) The spatial relationships and evolutionary trends of different indicators of light rain events and PM_2.5 concentration are significantly different; the role of light rain events in winter and spring seasons, especially the number of light rain days in winter and spring, in relation to PM_2.5 concentration is significantly stronger than that on an annual scale; 4) The trade-offs and synergistic relationship between PM_2.5 concentration and light rain events and their evolutionary characteristics show significant spatial and temporal heterogeneity in different management zones, and the river valley plains and the soil and rocky mountainous areas with higher levels of urbanisation and industrialisation are the areas with the most significant changes in the trade-off-synergistic relationship between PM_2.5 concentration and light rain events in the Loess Plateau, and are the sensitive areas for the relationship between the two.

In this article, we selected Tielishahan peatland and Halasazi peatland in the Altay Mountains, Northwest China as the research objects. We used AMS¹⁴C to establish a dating framework and determined trace and macronutrient contents in two peat cores to reconstruct the historical Holocene atmospheric dust deposition process and its influencing factors in high mountainous areas in Northwest China. The results show that atmospheric dust deposition fluxes recorded from Tielishahan and Halasazi peat cores ranged from 22.74 to 76.92 and 18.60 to 198.38 g/(m²·a), respectively. Atmospheric deposition is the main source of mineral element and water recharge in the Halasazi peatlands, which is more representative of the changes in dust activity in the region. The dust fluxes recorded in the Halasazi peat show higher dust fluxes during the early Holocene and early-middle Holocene periods and lower dust fluxes after the middle Holocene. Compared with other regions, the Holocene dust fluxes from the peat record in the Altay region were higher than those from the peat record in the monsoon region. A decreasing trend observed in the Altay region after the middle Holocene, contrary to the conclusion that the peat records of the monsoon region which showed higher dust fluxes in the late Holocene. The dust sources and the characteristics of the climatic environment were the main reasons for the differences in dust flux variation processes in different regions. Humidity and temperature variations directly affect the vegetation cover status in the dust source area of the northwest arid zone of China, and further affect the variation of atmospheric dust fluxes in the region. However, differences in local environmental and permafrost variation can also cause significant differences in the atmospheric dust information recorded by different environmental carriers. This study is of great scientific significance for a more comprehensive and accurate understanding of the atmospheric environmental change processes and their main influencing factors in different regions of China.