The major drought records with detailed disaster descriptions from Pre-Qin Dynasty to Qing Dynasty (850 a B.C.—1911 a A.D.) are extracted from historical documents and historical material records. The entropy weight method was used to determine the comprehensive index of major drought, and the spatial autocorrelation, barycentric analysis and standard deviation ellipse were used to study the distribution pattern and change process of major drought in historical period of China. The results show that: 1) From Pre-Qin Dynasty to Qing Dynasty, the frequency of major drought in China was 580 times, with an average of once every 4.76 years, showing an overall upward trend. 2) On the whole, the frequency of major drought in the north is higher than that in the south, and the highest frequency of drought is in some counties of Shaanxi, Henan and Shandong. 3) The Ming Dynasty is the period with the highest cumulative level of major drought, and nearly 56.81% of the areas in China have experienced major drought. The cumulative grade of major drought has significant spatial autocorrelation, and its correlation changes have experienced the process of “increase-decrease-increase-decrease”. The Moran index of the whole period is 0.43, which has significant spatial agglomeration. 4) The number of counties with major drought accounted for 21.42% of the total number of counties with major drought. Its center of gravity is always located in Henan Province, moving in the direction of “southwest-northeast-southwest-southeast-northwest”. 5) The frequency of major drought was significantly negatively correlated with temperature and precipitation. The terrain conditions of high in the west and low in the east of China, temperate continental monsoon climate and unreasonable human activities are related to North China and its surrounding areas becoming the hardest hit areas. In addition, climate change and population distribution have an important impact on the changes in the distribution pattern of major droughts in historical periods.

Using the panel data of 41 prefecture-level and above cities in the Yangtze River Delta (YRD) urban agglomeration from 2010 to 2021, the spatio-temporal pattern of the level of integrated urban-rural development in the study area is analyzed by constructing a multidimensional comprehensive evaluation system, and the influencing factors are resolved by using a Geodetector model. The results show that: first, the overall integrated urban-rural development level of the YRD urban agglomeration shows a steadily increasing trend, rising from 0.499 7 in 2010 and 0.5729 in 2015 to 0.6488 in 2021, with an average growth rate of 2.40%. The average annual growth rate of integrated urban-rural develomment level in three provinces and one municipality is Anhui, Shanghai, Zhejiang and Jiangsu in descending order, and the highly and medium-highly integrated areas are increasing with time. Second, regarding the overall characteristics of the evolution of spatial and temporal patterns, the urban-rural integration level within the YRD city cluster exhibits significant spatial disparities. High-value and medium-high-value areas are primarily concentrated in the central part of the cluster, while medium-value areas are adjacent to these zones, forming a contiguous distribution. In contrast, most of the western areas, except for Hefei, are characterized by lower levels of integration. Third, in terms of the sub-dimensional characteristics of the evolution of spatial and temporal patterns, the urban-rural integration level of the YRD city cluster in all sub-dimensions shows an upward trend. Among them, the average annual growth rate of the public service equalization index is low, only 1.19%, the average annual growth rate of the per capita income convergence index is 1.73%, the average annual growth rate of the ecological environment integration index is 2.54%, and the integration index of infrastructure has the fastest growth rate of the four sub-dimensions, with an average annual growth rate of 3.58%, which is also evident in the spatial pattern of differentiation. Fourth, from the detection results of the influencing factors, the level of financial support for agriculture, the level of urbanization, the level of economic development, the advanced industrial structure, and the degree of openness to the outside world are the important factors driving the integrated urban-rural development of the YRD urban agglomeration. Fifth, from the results of the interaction detection of the influencing factors, the average q-value of the interaction of each influencing factor is above 0.5, i.e., the explanatory strength of the interaction of the two factors is greater than that of the single factor, and the spatial and temporal differentiation of the integrated urban-rural development of the YRD urban agglomeration is the result of the joint action of multiple influencing factors.

Industrial heritage is an important resource and cultural carrier of industrial tourism. How to realize the organic integration between industrial heritage and tourism utilization has become an urgent problem for the sustainable development of industrial heritage. In this paper, industrial heritage in northeast China is selected as the research object, and ArcGIS spatial analysis, concentration index and resource dominance are used to analyze its spatial distribution characteristics, and the relationship between industrial heritage resources and tourism utilization is discussed. The following conclusions are drawn: Industrial heritage in northeast China is dominated by heavy industry and less light industry, and the type distribution is significantly different among provinces. The spatial distribution type of industrial heritage in northeast China is clustered, and it shows an obvious unbalanced structure at city scale. The superiority degree of industrial heritage resources in northeast China is quite different, which mainly has the distribution characteristics of polar core area, highly dense area, sub-dense area and sparse area. Based on this, the author puts forward the utilization methods of industrial heritage tourism from the aspects of promoting the overall balanced development of industrial heritage resources, accelerating the transformation of industrial heritage resources into products, and promoting the brand building of industrial heritage resources products, so as to provide reference for the sustainable development and utilization of industrial heritage.The industrial heritage resources in northeast China exhibit spatial distribution differences, low levels of resource to product conversion, and weak brand effects. Based on this, promote the overall balanced development of industrial heritage resources in the region, form an effective connection and interaction of regional industries with “industrial culture+”, and enhance the potential and efficiency of linkage; Accelerate the transformation of industrial heritage resources into products, and in the process of preserving, changing, and restructuring the functions of various industrial heritage resources, adapt to the needs of urban functional development, and promote the cross-border integration of cultural and tourism resources; Promote the branding of industrial heritage resource products, fully explore industrial cultural elements in the branding of various industrial heritage resources, and propose industrial heritage tourism utilization methods in terms of creating themed, diverse, and experiential industrial tourism products, providing reference for the sustainable development and utilization of industrial heritage.

Over the past 2 centuries, the lakes of the Northeast Plain and mountainous regions have been subjected to the dual impacts of climate change and human activities, leading to a series of ecological degradation issues. Understanding the historical evolution and driving mechanisms of lake ecological environments is crucial for the restoration of lake ecosystems in the future. However, there is a research gap in the reconstruction of the ecological environment of modern lakes in Northeast China. To address this, we utilize sediment n-alkanes, grain size, total organic carbon (TOC), total nitrogen (TN), and carbon-to-nitrogen ratio (C/N) to investigate the evolutionary patterns of Woniu Lake over the past 200 years based on ²¹⁰Pb and ¹³⁷Cs dating. By integrating modern monitoring data and historical records of the basin, we further evaluate the driving factors behind various environmental pressures on the lake's evolution. The results showed that the environmental evolution of Woniu Lake is broadly consistent with regional socio-economic transitions. Prior the 1940s, Woniu Lake was in a natural evolutionary phase with low and stable productivity, and its organic matter was primarily derived from external sources. Aquatic plant biomass was low, and the lake was in a relatively weak hydrodynamic conditions. The watershed environment was stable, with forest coverage dominant and minimal human impact. However, from the 1940s to the 1990s, human activities such as agricultural irrigation and deforestation exacerbated the decline in lake water levels and the input of external nutrients, resulting in elevated primary productivity and enhanced contributions from autochthonous organic matter, with organic matter inputs mainly from large aquatic plants. This led to a degradation of the lake's ecological environment, but without any significant state changes. After the 1990s, the algal productivity indicated by short-chain n-alkanes of Woniu Lake sharply increased due to the rapid development of modern industry and urbanization in the basin, leading to a transition to eutrophication. Redundancy analysis and variation partitioning analyses showed that nutrient factors played a key role in influencing the ecological evolution of Woniu Lake, independently accounting for 30.3% of the variance, alongside climate factors and watershed erosion from the 1950s to the 2020s. Since the 1990s, human activity factors became predominant over natural environmental factors and, in interaction with nutrient factors, became the main control of the short-term organic matter sources in Woniu Lake. The significant enhancement of human interference has led to the lake's transition to eutrophication under the combined stress of multiple pressures.

The Hobq Desert is the seventh largest desert in China, and it is also the most distributed desert in the east. In China, the water and soil resources are better in the desert, and it is the area with the most work in the practice of sand prevention and control in China. The information of desertification land change is one of the core index pieces of information of ecological restoration project effectiveness evaluation. In order to deeply analyze the change of desertification land in this area, the remote sensing images from 1987 to 2022 were selected. Based on 3S technology, the NDVI pixel dichotomy model was used to calculate the temporal and spatial dynamic changes of desertified land. Quantitative analysis of the influencing factors affecting the spatial change of desertification land was carried out by using geographic detector. Finally, the PLUS model was selected to predict the distribution pattern of desertified land in 2032. The results showed that: 1) During the 35 years, the vegetation coverage of the Hobq Desert showed an overall growth trend, from 13.59% to 30.43% ; from west to east, there is a clear division from mobile sandy land to fixed sandy land, and the vegetation in the north is mostly along the yellow section. 2) The area of mobile sand decreased by 50%; the area of semi-fixed sandy land increased by 10%, mainly from the management of mobile sandy land. Fixed sandy land increased by 89.80%, with the largest increase of 2.3% in 2017. 3) The desertification cultivated land increased from 13.98% to 17.56% in 35 years, with an average increase of about 1%-2% every 5 years. 30.83% of the increase in the area of desertified cultivated land came from semi-fixed sandy land, and 6.49% came from mobile sandy land. Abandonment or encroachment of desertified farmland led to an increase of 18.97% in grassland area. 4) Social and economic factors are the dominant factors of land use change in the Hobq Desert. In the future, the Hobq Desert will develop in the direction of increasing semi-fixed sand, fixed sand, forest land, grassland, cultivated land and other resource-based land. The reduction of desertification land and the increase of vegetation cover in the study area can provide reference and data reference for the follow-up desert control and desert project implementation along the Yellow River.

The urban thermal environment is deteriorating due to global warming and urbanization. Scholars worldwide are focused on lowering the land surface temperature (LST) to mitigate this issue. Building morphology significantly influences LST by affecting thermal radiation and wind speed. While numerous studies have examined the impact of 2D and 3D building morphologies on LST, many have lacked comprehensive consideration of relevant indicators and thorough analysis based on zoning schemes for various architectural features. In this study, the central urban area of Tianjin was used as a case study, and Landsat-8 remote sensing imagery was utilized to retrieve LST using the radiative transfer equation to characterize the urban thermal environment. Concurrently, building data were employed to quantify 17 building morphology indicators and identify 9 typical urban form prototypes. Subsequently, the differences in LST among the various urban form prototypes were analyzed, and the thermal environmental effects of building morphology within these prototypes were examined using multiple linear stepwise regression. The findings indicate that: 1) significant differences in summer LST were observed among different urban form prototypes, with the highest mean LST in low-rise, high-density blocks (42.58℃) and the lowest in high-rise, low-density blocks (38.16℃); 2) building morphology within different urban form prototypes had a significant impact on summer LST, although the degree of influence varied. The high-rise, high-density blocks had the greatest influence on LST (explanation degree of 45.9%), while the multi-rise, low-density blocks had the smallest influence (17.6%); 3) within typical urban form prototypes, there was a coexistence of differences and consistency in the response of summer LST to various building morphology indicators. Across all urban form prototypes, the direction of influence of each building morphology factor on LST was consistent, but its relative importance varied. Therefore, future urban planning and urban renewal should avoid low-rise, high-density configurations and prioritize high-rise, low-density ones to enhance the thermal environment. Adjusting and regulating building morphology within limited land and space resources can improve the urban thermal environment. Differentiated building morphology planning and design strategies should be implemented with targeted solutions based on the thermal effects of various urban form prototypes.

Urban inclusive innovation is the most fundamental value orientation of urban innovation in the context of Chinese path to modernization, which is more conducive to promoting equitable and sustainable urban development than traditional urban innovation. Based on the connotation of urban inclusive innovation, this paper constructs a measurement framework for urban inclusive innovation, empirically analyzes the spatial pattern and influencing factors of Beijing’s urban inclusive innovation by using entropy method, spatial autocorrelation and geographical detector model. The results show that: 1) Urban inclusive innovation is an innovative act based on inclusive innovation policies that create opportunities for the public to participate in innovation activities and share the fruits of innovation in a fair manner, so as to realize the relatively fair development of urban innovation, and its measurement dimension include inclusive innovation policies, equity of opportunity for participation and sharing of innovation outcomes. 2) The overall level of urban inclusive innovation in Beijing decreases from the central urban area to the surrounding area, and shows a phenomenon of agglomeration in spatial distribution, with high-high clusters concentrated in the Dongcheng District, the Xicheng District, the Chaoyang District and the Fengtai District, and low-low clusters concentrated in the Huairou District and the Miyun District. 3) The formation of the spatial pattern of Beijing’s urban inclusive innovation is the result of a combination of factors, with culture, education and industrial structure being the most important influencing factors, and any 2 factor interactions are bifactor enhancement or nonlinear enhancement relationships. Finally, this paper proposes policy recommendations for Beijing in developing urban inclusive innovation based on the findings of the study.

Establishing and facilitating high-quality talent flows is a crucial way to China’s international talent cultivation and intellectual-attraction country construction. Drawing on international student mobility data among 39 countries including OECD countries and China in 2019, this research constructed a weighted and directed international talent mobility network, and employed social network analysis to explore its spatial patterns and influencing mechanisms. 1) International student exchanges were quite tight among the 39 countries, forming 4 visible regional communities, i.e., the North American and Asia-Pacific community, the South America and European community, the Nordic and Baltic community, and the Czechoslovakian community. China and the United States were centers of international talent exchange. Moreover, China, the United Kingdom, Germany, the United States and France were also the gateways and hubs of international talent flows. 2) The patterns of international student outflows and inflows of 39 countries were asymmetric. The outflows of Chinese students accounted for nearly half of the total, while the outflows of OECD countries were relatively balanced. The United States, the United Kingdom and Australia ranked the top 3 in international student attraction, followed by China with 7.17% international student inflows. 3) The impact of openness degree, education quality, economic level on international student mobility all suggested sender and receiver effects. The proximity in geography, language and culture, and commodity trade could promote the bi-directional talent flows. The structure dependence effect was an important driver to the evolution of international student mobility network, with the reciprocity, preferential attachment and transitive closure effects being most pronounced, which could somewhat substitute the effects of exogenous force. There is still much room for the improvement of the talent mobility among China and OECD countries. It can be optimized from the perspectives of the country’s endowments, multi-dimensional proximity, and network structures, to promote a more flat and diversified patterns of talent mobility among these countries.

Based on the connotation of urban-rural integrated development, 78 prefecture-level cities in the Yellow River Basin were taken as the case study areas, the evaluation index system of urban-rural integrated development in the Yellow River Basin was scientifically constructed from 5 dimensions, and multiple measurement methods were used to comprehensively study the spatio-temporal differentiation and driving mechanism of urban-rural integrated development in the Yellow River Basin in 2011—2021. The results are obtained as follows: 1) The level of urban-rural integration in the Yellow River Basin is generally on an upward trend, with low-level areas decreasing and high-level areas continuing to increase. The level of urban-rural integration in the downstream areas is generally higher than that in the middle and upstream areas, and generally shows a pattern of increasing from west to east; 2) Spatial clustering characteristics are significant, the overall existence of a more obvious spatial dependence, high value areas are mainly concentrated in the eastern and northern areas of the Yellow River Basin; 3) The integrated development of urban and rural areas is the result of multi-scale and multi-factor interactive and integrated development driven by the interaction of many factors, and the driving factors have obvious spatial and temporal differences, showing spatial heterogeneity in spatial bands or pieces of the distribution pattern.

Jilin Province boasts an abundance of wetland resources, yet human misuse and climate change have led to a decrease in wetland areas and a decline in function. Investigating the impact of climate change on plant diversity in wetlands is crucial for the protection and restoration of these ecosystems. Currently, information and research on the future climate suitability of wetland plants are limited, and few studies have used stacked species distribution models (SSDMs) to investigate wetland plant diversity. Therefore, we used SSDMs to simulate the current distribution patterns of 30 dominant wetland plant species in Jilin Province, based on 6601 sample points and 19 environmental factors. We identified the main factors driving the distribution of each species, and predicted changes under three future climate scenarios (SSP1-2.6, SSP3-7.0, and SSP5-8.5) in the future (2071—2100). Our results show that: the precipitation of the wettest quarter, soil pH, and max temperature of the warmest month are identified as crucial factors affecting the distribution of marsh wetland plant species. Species richness in the eastern area is higher than that in the west, and it is unevenly distributed throughout Jilin Province, with the highest richness found in Dunhua City; under climate change, the distribution range and species richness of dominant marsh wetland plant species will decrease in Jilin Province; most of the dominant wetland plant species in Jilin Province have already protected, but the simulations show some suitable distribution areas and areas at high risk in the future that should be taken into account when building the conservation network. This study could provide a scientific basis for the conservation of wetlands in Jilin Province.

Resilient cities are a requirement for urban sustainable development and high-quality development. Based on the panel data of the Zhongyuan Urban Agglomeration from 2006 to 2019, this paper constructs an evaluation system to measure the urban resilience of the Zhongyuan Urban Agglomeration. Using exploratory spatio-temporal data analysis methods, we investigate the spatial and temporal evolution characteristics of urban resilience in the Zhongyuan Urban Agglomeration, and explore the spatial and temporal transition mechanism of urban resilience with the help of quantile regression. The results show that: 1) the spatial distribution of urban resilience in the Zhongyuan Urban Agglomeration is dominated by low-low cold spot agglomerations of negative correlation type, with significant spatial homogeneity. 2) the spatial evolution of urban resilience in the northwestern Zhongyuan Urban Agglomeration and the area near Zhengzhou City is more dynamic, and the spatial structure of the less resilient urban areas has stronger stability. 3) The local spatial structure of urban resilience level is more stable, and some of the study units have a strong transfer inertia. 4) In the low quantile stage, urban agglomeration is an important factor limiting the development of urban resilience, and economic development, government finance, technological innovation, public services and ecological environment are important factors driving the development of urban resilience; in the high quantile stage, urban agglomeration is an important factor that hinders urban resilience development, and economic development, government finance and ecological environment are important factors that drive urban resilience development.

Based on daily precipitation data from 1970 to 2020, we analyzed the spatio-temporal variation of precipitation seasonality index (PSI) in south and north Qinling Mountains. Then, the empirical orthogonal function (EOF) analysis is performed to identify the leading spatial patterns of PSI in the study region. More specially, we discussed the relationship between the leading spatial patterns of PSI and sea surface temperature anomaly (SSTA). The results show that: 1) The change of PSI in south and north of the Qinling Mountains was mainly synchronous variation over the past 51 years. Before 1997, it could be observed one peak (dry) periods (1975—1986) and two valley (wet) periods (1970—1975 and 1987—1996) of PSI variation. After 1997, the precipitation showed markedly seasonality with a long drier season in 1997—2015, which indicated the dry climate is becoming the normal condition for China’s south-north transitional geographical zone. 2) Spatially, the single type of precipitation seasonality is clearly seen over most regions (61.3% of the study area) and the combined type of precipitation seasonality (32.7% of the study area) does not prevail. In detail, for the single type, the eastern part of Hanjiang River Basin and western part of Daba Mountains (28.3% of the study area) are mainly controlled by a longer wet season. Moreover, precipitation seasonality with the dry−wet balance accounted for 22.9% of the study area, which located in the west of Jialing River Basin, Hanzhong Basin, Ankang Basin and the middle of Guanzhong Plain. 3) This study investigates the first leading spatial patterns of the interannual variability of PSI in the south and north Qinling Mountains. The positive phase of the first leading mode (EOF1) showed characterized by positive PSI anomalies for the whole region. The positive phase of EOF1 was significantly associated with the negative phase of North Atlantic Oscillation (NAO) from pre-winter to spring, as well as the transition from El Niño in pre-winter to La Nina in summer.

Based on Baidu search index big data mining, this article constructs China’s regional economic uncertainty index, which measures regional economic uncertainty by capturing the subjective cognitive attitudes of micro subjects’ search behaviors that reflect “uncertainty”. The Chinese regional economic uncertainty index is measured and analysed in time series at the national and provincial scales, respectively. The DY spillover index model is used to study the static spillover effect, dynamic spillover effect and net spillover effect of cross-regional economic uncertainty. On this basis, the spillover network model of inter-regional economic uncertainty is constructed using the complex network method to examine the path of inter-regional uncertainty contagion, and the main conclusions are as follows: The constructed regional economic uncertainty index is able to identify the fluctuation of uncertainty caused by major events effectively. The occurrence of major economic, geopolitical and public health events can trigger a sustained rise in regional economic uncertainty. The results of the spillover network analysis show that the middle reaches of the Yangtze River and the southwest economic zones of China are the main exporters of spillovers in the system, and other regions, such as the eastern coastal economic zone, play the role of spillover receivers. Cross-regional economic uncertainty is transmitted mainly from the southwest economic zone to the eastern coastal economic zone, and from the middle reaches of the Yangtze River to the southern coastal economic zone. Regional economic policymakers should establish and improve cross-regional economic uncertainty coping mechanisms, identify and understand the time-varying characteristics of economic uncertainty based on regional resource endowments, development levels and specificities, scientifically formulate differentiated regional economic risk prevention and control policies, and maintain policy continuity and stability. Through scientific and technological innovation and industrial upgrading, it will promote high-quality development of the regional economy and reduce its sensitivity to uncertainty shocks.

The migratory birds, constituting individuals engaged in seasonal migration, represents a prominent area of inquiry in the study of population migration. This article presents a comprehensive synthesis of pertinent scholarly literature, systematically summarizing the identification pathways, migration scale and characteristics, migration motivations, social effects, and social integration pertaining to the migratory birds. Current research indicates that the migratory birds, primarily comprising middle-aged and elderly individuals, undertake extensive, long-term, and large-scale migrations to regions endowed with superior natural environments, driven by their quest for enhanced well-being. Migration motivation is influenced by factors encompassing living environments, social relationships, economic motivations, and healthcare services. Ongoing researches on the social effects of migration continue to generate debate. The migratory birds exert multifaceted impacts on the socio-economic fabric, with the majority of scholars acknowledging their positive effects on local economic development, industrial restructuring, and social interactions. However, a subset of scholars posits that the cyclical flow of the migratory birds engenders challenges such as seasonal shortages of public service resources during peak periods and underutilization of commercial land during off-peak seasons. Moreover, the issue of social integration of the migratory birds has gained increasing scholarly attention, with a prevailing consensus that the migratory birds exhibit relatively low levels of social integration. Further endeavors to deepen interdisciplinary integration of disciplines such as demography, geography, and sociology, while expanding the repertoire of identification and data collection methodologies for the migratory birds, should be directed towards an exploration of the distinctive characteristics of population migration in the “era of the migratory birds” from the perspective of human geography. This entails heightened research focus on emerging domains such as “migratory talent”“reverse migration”“sunbird” and “cross-border migrants” thereby facilitating the provision of a more scientifically rigorous foundation for second place of residence planning and social policy development.

Overseas energy investments serve as a critical safeguard for China’s energy security. Understanding the spatiotemporal dynamics and spillover effects of China’s global energy layout provides valuable insights for optimizing investment strategies and refining planning policies. This study utilizes the China Global Energy Investment Tracker, a fixed panel regression model, the geopolitical risk index, and GIS spatial analysis to examine the structural evolution and multifaceted impacts of China’s global energy investments. The key findings are as follows: 1) China’s global energy layout follows a “rise-then-decline” temporal pattern characterized by significant fluctuations. Renewable energy has emerged as the primary growth driver, while project failure rates have steadily decreased. 2) The energy layout remains predominantly led by state-owned enterprises (SOEs), although the role of private enterprises has grown substantially. The regional specialization of enterprises has weakened, showing a trend toward more balanced overseas site selection. 3) The role of developed countries in China’s global energy layout has significantly diminished, while the proportion of projects located in Belt and Road Initiative (BRI) countries has increased markedly. Renewable energy projects are actively expanding into international markets, facing relatively lower geopolitical risks, whereas traditional energy projects remain stable but are increasingly exposed to heightened geopolitical challenges. 4) China’s global energy layout exhibits implicit carbon transfer effects. Investments in traditional energy contribute to oil and gas import effects, while renewable energy projects play a pivotal role in advancing energy transition efforts. These findings offer critical perspectives for enhancing China’s overseas energy strategies in response to global energy transitions and the growing complexity of geopolitical risks.

Drought is a type of natural disaster that lasts for a long time and causes a lot of damage. It has a negative impact on the security of the water supplies in the region, human production and life, and economic growth. In order to analyze the spatial-temporal characteristics and underlying causes of vegetation drought in the middle Yellow River from 2000 to 2021, the temperature vegetation Precipitation Drought Index (TVPDI) was developed in this study using normalized vegetation index, surface temperature, and precipitation data. Additionally, the relationship between the implementation of the project to convert farmland in the middle Yellow River to forest and grassland and regional vegetation drought was examined. The findings revealed that: 1) The multi-year average TVPDI value in the middle reaches of the Yellow River from 2000 to 2021 showed an insignificant upward trend, and the average multi-year TVPDI value was 0.708, corresponding to a light drought grade. 2) TVPDI in the middle reaches of the Yellow River from 2000 to 2021 has a strong spatial differentiation, showing a spatial distribution pattern of “drought is lighter in the northeast and southwest regions and heavier in the northwest and southeast regions”; From the perspective of each geomorphic region, the drought in the loess plateau gully area is light, and the drought in the wind-sand area and the valley plain area is heavy. 3) The main factors affecting the spatial differentiation of TVPDI in the middle Yellow River are temperature, evapotranspiration and rainfall, and there is a significant linear relationship with TVPDI. In the middle reaches of the Yellow River from 2000 to 2021, vegetation coverage and evapotranspiration showed an increasing trend, while soil moisture showed a decreasing trend.

The Taishan Mountain is a world natural and cultural heritage. At present, the forest vegetation of the Taishan Mountain is mainly planted artificially in the 1950s and 1960s, so whether it has vertical zoning is controversial. In order to comprehensively analyze the vertical differentiation law of vegetation in the Taishan Mountain, this paper uses the high spatial resolution (WorldViewII, 0.5m) remote sensing image, and refers to the sub class data of the “One Map” of the Taishan Mountain Forest Resources Management to classify the forest vegetation by visual interpretation method. On this basis, the Geo-info-spectrum and Altitude-slope-aspect graphic of deciduous forest, coniferous forest, coniferous and broad-leaved mixed forest in the Taishan Mountain were constructed. The main conclusions are as follows: The vertical differentiation of forest vegetation in the Taishan Mountain is significant, which belongs to the “disturbance band spectrum” greatly affected by human activities. At an altitude of 200-600 m, coniferous forests, broad-leaved forests, and mixed coniferous and broad-leaved forests are mixed in a disorderly manner; On sunny and semi sunny slopes with an altitude of 500-1 000 m, deciduous broad-leaved forests are concentrated, while on shaded and semi shaded slopes, temperate coniferous forests and deciduous broad-leaved forests are mixed; Concentrated distribution of temperate coniferous forests at an altitude of 1 000-1 500 m. This research is the first time to comprehensively and quantitatively analyze the vertical differentiation of forest vegetation in the Taishan Mountain, which has reference significance for further accurate analysis of the quantitative relationship between the Taishan Mountain vegetation landscape and environmental factors, as well as the habitat protection and biodiversity restoration of the Taishan Mountain World Heritage Site.

The study is based on the maximum value composite MODIS NDVI data of growing seasons (GNDVI) from 2000 to 2020 in the Three River Headwater Region (TRHR). It uses trend analysis and spatial analysis methods to quantify changes in grassland greenness in the region. Additionally, correlation and partial correlation analyses are applied to explore the relationship between temperature, precipitation, and GNDVI at different temporal and spatial scales. The results of the study show that: 1) From 2000 to 2020, the overall trend of grassland GNDVI in the TRHR has increased, with 77.53% of pixels showing an increasing trend. Among these, 33.95% of pixels show a significant increase (P<0.1). On the other hand, a decrease is observed in some areas, with 22.47% of pixels showing a decreasing trend, and 3.03% of these showing a significant decrease (P<0.1). 2) The pixels with a significant increase in GNDVI are mainly found at elevations of 4500-5000 m and on north-facing slopes with a gradient of 2°-6°. Conversely, the pixels with a significant decrease in GNDVI are primarily located at elevations of 4500-5000 m and on south-facing slopes with a gradient of 6°-15°. 3) Overall, in the TRHR, GNDVI shows the strongest correlation with temperature and precipitation during the growing season. The correlation with the minimum temperature during the growing season (R=0.79, P<0.001) is stronger than with precipitation (R=0.66, P<0.001) and average temperature (R=0.55, P<0.001). The relationship between monthly climate factors at the grid scale and GNDVI shows that the interannual fluctuations of GNDVI are most strongly correlated with precipitation and minimum temperature in July. Spatially, the eastern GNDVI is primarily influenced by precipitation, while the western GNDVI is mainly driven by temperature.

Microbes play an important role in improving soil fertility and nutrient cycle. Exploring the soil microbial community characteristics under different revegetation types can provide scientific basis for the restoration and reconstruction of karst degraded ecosystem. In this study, 5 vegetation restoration types (i.e., Macadamia integrifolia, Juglans regia, Morus alba, Caesalpinia sappan and enclosure forest) were selected to analysis the α diversity and community structure of soil bacteria and fungi and their controlling factors. Results showed that compared with the abandoned land, vegetation restoration had a significant impact on soil physical and chemical properties, with the greatest effect of enclosure forest on improving soil organic carbon (SOC) and nitrogen and phosphorus nutrient content. Different types of revegetation enhanced the α diversity of soil microorganisms in different degrees, with the most significant influence on bacterial richness and pedigree diversity under Morus alba, and on fungal richness and shannon index under Juglans regia. Soil pH, NO₃ ⁻ and Ca²⁺ contents were positively correlated with bacterial α diversity (richness, shannon index and pedigree diversity index). Revegetation significantly changed microbial community structure, which was mainly manifested in that compared with abandoned land, Juglans regia significantly increased the relative abundance of Planctomycetes and Basidiomycetes, and Macadamia integrifolia significantly increased the relative abundance of Ascomycetes. Redundancy analysis showed that the contents of soil Ca²⁺ and TN were the relative important influencing factors of microbial community structure. Our findings indicate that the plantations of Morus alba and Juglans regia had a remarkable effect on improving microbial diversity, which will help to improve the stability of soil ecosystem. Macadamia integrifolia significantly increased the abundance of Ascomycota, which may play an important role in enhancing soil erosion resistance. Natural enclosure forest had obvious effect on increasing soil organic carbon, nitrogen and phosphorus nutrients, which is of great significance to improve soil fertility in karst degraded ecosystem.

Blowouts are the main subject of aeolian geomorphology study, and the morphological-dynamics process is the important issue of studying blowouts. Recently, after the artificial foredunes on the coast was generated due to artificial interference, it is urgent to carry out corresponding research along with the emergence of a large number of blowouts, but there is a lack of relevant research on the blowouts developed on the artificial foredunes so far. Pingtan Island, which has a typical development of wind blowouts on the artificial foredune, was selected as the study area, Here we study the feedback mechanism between aerodynamics and morphodynamics processes on artificial blowouts through surveying topography by high-resolution RTK-GPS, and monitoring aerodynamics process by 2 dimensional ultra-sound anemometers. The preliminary results show that: 1) The trough blowout was developed in artificial foredunes controlled by artificial filled clay structures. It displayed a different development path (a cycle) from previous observation, which started with the sediment-transport channel, to a fully developed blowout until died out, lastly went back a new sediment-transport channel. 2) The morphology of trough blowout controlled how wind flow moved within blowout, which promoted deflation basin of blowout increasing due to positive feedback. 3) The two-way feedback between blowout topography changes and aeolian process, which aerodynamic process lead to the morphology changes and morphology affect the operation mode of the process. As the angle between wind direction and long axis of trough blowout increases (48°~99°), flow deflection in the blowout was clearly visible and the helicoidal flow usually appeared.

Based on comprehensive population census data spanning from 2000 to 2020, alongside relevant socioeconomic indicators, a comprehensive analysis has been undertaken to explore the intricate spatial and temporal evolution of the floating population structure across various counties within Fujian Province, China. This analysis delves deep into the complex factors that influence this population dynamic and finds that: The trend of intra-provincialization of the floating population structure in Fujian Province has increased, and rapidly intra-provincialized areas are spatially connected into three horizontal axes in the “southeast-northwest” direction. A closer examination reveals that, compared to urban centers or municipal districts, the shift towards intra-provincialization is even more pronounced in counties and county-level cities. In addition, this study conducted research on economic development level, industrial structure, administrative division level, air quality, public service conditions, and regional differentiation in coastal and inland areas, and found that: the growth of employment scale in the secondary industry are directly linked to encourages the inter-provincialization of floating population. Conversely, the growth of employment scale in the tertiary industry encourages intra-provincialization of floating population. Counties encourages intra-provincialization of floating population too. Additionally, inland regions, unlike their coastal counterparts, demonstrate a heightened sensitivity to changes in environmental factors such as air quality and public service provisions, which further shape the floating population structure. The significance of these findings lies not only in enhancing our grasp of population mobility patterns within China but also in their practical applications. The research findings have significantly broadened our comprehension of the intricate transformation patterns observed in China’s population mobility structure. Moreover, these insights can serve as a valuable reference for policymakers and planners aiming to foster high-quality development and the rational allocation of public service resources in the southeastern coastal regions of the country. By considering the subtle interactions between economic, environmental, social factors, and floating population structure, more responsive and sustainable policies can be designed and implemented. Ultimately, this will help improve the livelihoods and social welfare of floating population in Fujian and other regions.