The change of land use and land coverage is an essential research topic in global change studies. Coastal zones are hotspots in this research field. We obtained land use and land cover data (CLCD) in the coastal zone of mainland China from 1985 to 2021. Land use change rate, transfer matrix of land use, geo-spectrum of land use change, indicators of United Nations’ Sustainable Development Goals (SDGs) 15.1.1,15.2 and 15.3.1 were used to analyze the characteristics of land use change and the progress in achieving the SDGs in the coastal zone of mainland China. 1) From 1985 to 2021, the overall trend of land use and land cover change in the coastal zone of mainland China was mainly characterized by cropland shrinkage and impervious surface expansion, followed by forest land expansion, then shrub, grassland and barren land contraction, and small expansion of water. 2) The main types of land use were cropland and forest in the coastal zone of mainland China in the beginning of the study period, but in the later years, cropland, forest and impervious surface were the main types. 3) The spatial separation degree of land use change was low in the study area, and the rate of change from cropland to impervious surface was the highest, and it was concentrated in the economic circles with high population density such as the Bohai Bay, the Yangtze River Delta and the Pearl River Delta. 4) In terms of SDG indicators, the SDG indicator 15.1.1 (forest coverage) increased by 0.88% (4 088.89 km2) in the coastal zone of mainland China. The SDG Indicator 15.1.1, forest area as a proportion of total land area, shows a promising sign of achieving SDG Target 15.1.1. Forests are effectively restored and controlled, showing a promising sign of achieving SDG Target 15.2. The land degradation rate rapidly increased in the early stage and stabilized in the later stage, with a land degradation rate of 11.76% in the study area over the past 36 years. Land degradation remains the main pattern of land change in the coastal zone of mainland China which suggests that in order to achieve a land degradation-neutral zone by 2030 as stated by SDG Target 15.3, more efforts are needed. Nonetheless, in the future, it is necessary to rationally plan the land use in the coastal zone of mainland China and dramatically improve land quality.
Based on hourly ozone monitoring data from 1836 monitoring stations in 338 cities in China, this study investigates the spatial and temporal characteristics of ozone concentration variation in different climatic zones, and reveals the relative contributions of natural and social factors to ozone pollution in different climatic zones and their key influencing factors. The results show that the annual evaluated values of ozone concentration in Chinese cities range from 84 to 193 µg/m3, with an annual average concentration of 141 µg/m3 and good urban air quality. However, 22% of the cities in China still exceeded the annual ozone assessment value, accounting for about 6% of the total number of days in the year. Urban ozone pollution has a strong spatial heterogeneity, temperate climate zone urban ozone pollution is the most serious, exceeds the standard city up to 44%, the average number of days exceeded about 10% of the year, ozone concentration level is light pollution, (Jinan, Zibo and Binzhou, etc.); The ozone concentration standard in the arid and semi-arid climate zone was excellent, with only 1% of the days of the year exceeding the standard. Urban ozone concentrations have strong seasonal characteristics, generally higher in spring and summer than in autumn and winter. Average ozone concentrations are highest in summer (109 µg/m3), followed by spring (108 µg/m3) and autumn (86 µg/m3), and lowest in winter (67 µg/m3). Redundancy analysis shows that social factors (PM2.5 and GDP etc.) are the main factors influencing the increase or decrease of urban ozone concentrations, with natural factors playing a secondary role. There is significant variability in the influence of natural and social factors on ozone in different climatic zones. This study can provide important theoretical support for cities in China to effectively cope with ozone pollution and build livable cities.
This paper systematically investigated the positioning, technological system and implementation guarantee measures of metropolitan planning. Metropolitan planning is positioned as a specialized planning for specific regions in the territorial spatial planning system. By clarifying the geographical definition and connotascope of metropolitan area as the fundamental basis of research, following logical steps of “central city-urbanized area-functional area”. Most of all, a new technological system of metropolitan planning was established from a goal-oriented, problem-oriented and implementation-focused perspective as follows. Firstly, an approach to overcome the local benefit contradiction in metropolitan planning may be to unify the demands of different cities into a common goal of development, calling for collaborative and concerted actions on construction of traffic network, industrial development, market consolidation, science and technology cooperation, information sharing and ecological restoration through metropolitan area. Secondly, what to plan in metropolitan planning should take into account the different development stages and government affairs. On one hand, a systematic analysis on the content of metropolitan planning was conducted in this paper following the principles of “corresponding to the development stages” to achieve the objective of practicability and validity; on the other hand, the key to adjust the overlapping content of plans is to figure out the responsibility of planning authority of the central and local governments, and to link the content with limited administrative jurisdictions of the metropolitan government. Last but not the least, the paper suggested to speed up the innovation of mechanism in order to optimize the implementation of metropolitan planning, and a guarantee system for the implementation was proposed with improvements from 5 aspects: institutional construct, coordination mechanism, law insurance, finance support and policy enforcement. It provided advanced theoretical references and methodological guidance for the spatial planning and governance of China’s metropolitan area in the new era.
In the context of mass tourism, the collective influence of tourists’ actions is increasingly evident, with occurrences of uncivilized, unfriendly, and destructive behaviors towards cultural heritage. These behaviors exacerbate the conflict between the economic and social benefits of tourism. Tourists’ heritage conservation behavior is crucial for the sustainable development of destinations. Some previous studies, based on the Cognitive Appraisal Theory, have found that tourists’ cognitive appraisals of the environment can evoke specific personal emotions, which in turn influence their heritage conservation behaviors. However, these studies predominantly focus on tourists’ cognitive appraisal of environment’s inherent characteristics, such as the uniqueness of tourism resources, the cleanliness and hygiene of destinations, and the quality of destination policy. Tourists’ appraisal of the relevance of the environment to themselves has received relatively less attention.This study, using the “environmental cognitive appraisal-emotion-behavior” framework of the Cognitive Appraisal Theory, examines several canal-themed museums in China and employs Structural Equation Modeling (SEM) , to analyze the mechanism by which perceived relevance of heritage history constructs tourists’ heritage conservation behavioral intentions. The results show that: 1) the perceived relevance of heritage history to social identity (RHSI) has a significant positive impact on heritage conservation behavior, while the perceived relevance of heritage history to self (RHS) and perceived relevance of heritage history to human condition (RHHC) does not show a significant relationship with heritage conservation behavior; 2) RHS, RHSI and RHHC all positively influence heritage conservation behavior through the mediating role of awe; 3) the authenticity of museum services positively moderates the effect of awe on heritage conservation behavior. These findings suggest that, to stimulate tourists’ heritage conservation behavior, heritage tourism destinations should strategically prioritize RHSI.
Rural tourism is an important driver of rural reconstruction, and the central question of how tourism drives rural reconstruction has been a hot topic of interest in both academia and industry. Existing studies have confirmed that tourism has a significant positive impact on rural reconstruction, but the specific evolutionary paths and mechanisms have not yet been identified, and the differences between rural reconstruction and natural evolution have been overlooked. Based on systems theory, this paper adopts a “rooted + case” approach to study typical tourist villages, reveals the mechanisms behind tourism-driven village reconstruction based on the dual logic of “deconstruction-reconstruction”, constructs a model of its evolution, and further compares it with villages in their natural state of evolution. The study finds that The study finds that: 1) The process of tourism-driven rural reconstruction is characterised by stages, with the primary stage of tourism-driven rural reconstruction not without the help of the “visible hand” of the government. 2) The essence of tourism-driven rural reconstruction is to realise rural value re-creation, the fundamental way is the interaction of the “people-place-industry” trilogy, the important support is the “three rural communities”-the rural organizational and cultural community, the rural geo-economic community and the rural multi-spatial community, the basic conditions are rural economic reconstruction, spatial reconstruction, social reconstruction and cultural reconstruction. 3) Tourism-driven rural reconstruction is a dynamic, developmental and cyclical process, which has gone through an initial stage of development from the economic and spatial reconfiguration led by “land, ecology, consumption and services” to the social and cultural reconfiguration led by “identity, otherness, revival and culture”. The initial stage of development will be the reconstruction of the economic and spatial dimensions led by “identity, otherness, rejuvenation and culture”, and the rapid development stage of reconstruction of the social and cultural dimensions led by “identity, otherness, rejuvenation and culture”. 4) Both tourism-driven rural reconstructions and villages in a state of natural evolution begin with economic reconstructions, and the core elements of both are “people-place-industry”, but there are differences in the course and speed of these reconstructions.
The popularity of mobile internet has given rise to digital consumption patterns represented by takeaway consumption. The spatio-temporal patterns of daily consumption supply and demand have changed. Using Hangzhou’s main urban area as a case study, the paper analyzes the spatio-temporal characteristics of daily digital consumption peaks using high-precision consumption data, mathematical statistics, kernel density spatial analysis, and visualization methods. Next, the study analyzes the spatio-temporal characteristics of supply and demand. The study found that 1) There are two peaks in digital daily consumption in metropolitan areas, noon and evening, and the degree of spatial and temporal concentration is higher during the noon peak. 2) During peak digital daily consumption periods, demand spaces show a significant clustering tendency, with the noon peak having higher spatial concentration than the evening peak, characterized by a smaller spatial range and more distinct boundaries. Demand space transitions from singular productive service land use to a mix of residential, productive, educational, and cultural land uses. 3) Supply space demonstrates high concentration, forming multiple supply centers. The distribution of supply space aligns broadly with traditional commercial spatial patterns, albeit with slight differences—key supply centers are primarily located within community-level business districts, with some situated in non-commercial areas. 4) The digital daily consumption exhibits two distinct characteristics: the misalignment of noon and evening consumption peaks and the misalignment of supply and demand peaks. Consumer temporal and spatial constraints during specific contexts result in the misalignment of midday and evening consumption peaks. In the digital age, stores continue to be governed by the agglomeration effect, forming a multi-center pattern. Delivery services expand the service radius and increase the geographical non-proximity between demand and supply, thus creating a misalignment between supply and demand peaks.
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.
The formation and development process of urban agglomeration is also accompanied by the evolution process of financial sustainable development ability of urban agglomeration, which is embodied in the “dynamic game” between economic development and financial transfer payment share among cities, and the financial sustainable development ability of urban agglomeration shows an evolutionary trend of wave climbing, showing an irregular wave climbing curve in time series. Firstly, this paper analyzes the basic principles of the evolution law of the sustainable financial development ability of urban agglomeration, and then models the geometric expression of the evolution law of urban agglomeration finance. Then, by constructing the evaluation index system of financial sustainable development ability of urban agglomerations, the scores of financial sustainable development ability of each Chinese urban agglomeration, the cities under its jurisdiction and the whole urban agglomeration are calculated by using entropy TOPSIS method. Then use ARCGIS10.2 to make a global spatial analysis of the financial sustainable development ability of different urban agglomerations and cities within urban agglomerations; The calculation method of game intensity and game threshold of financial transfer payment in urban agglomeration is established. Finally, we use the simulation method to fit and verify the evolution law of the financial sustainable development ability of China’s urban agglomerations, and then explore the financial sustainable development path of China’s urban agglomerations. Through the above research, the following basic conclusions are drawn: 1) The financial sustainable development ability of China’s urban agglomerations follows the evolution law of wave-shaped climbing; 2) By 2018, the financial sustainable development ability of other urban agglomerations except the central and southern Liaoning has been improved to varying degrees, and the average climbing speed of the overall financial sustainable development ability of urban agglomerations is 5.37%. The overall financial sustainable development ability of China’s urban agglomerations is mainly characterized by “high in the southeast-low in the northwest”, and the high-quality areas gradually spread from national urban agglomerations to regional urban agglomerations and regional urban agglomerations. 3) The game intensity of financial transfer payment among cities in urban agglomerations is increasing, but there are limitations of game thresholds, among which the game thresholds of national urban agglomerations, regional urban agglomerations and regional urban agglomerations are 406, 59 and 23, respectively. The game thresholds and game intensity between cities in national urban agglomerations are much higher than those of other two levels of urban agglomerations. 4) The climbing function curve of financial sustainable development ability of urban agglomerations has been verified by practice, and the function model of evolution law of financial sustainable development ability of urban agglomerations can be used to analyze and predict the future financial sustainable development ability law of Chinese urban agglomerations. Then, based on the above research conclusions, this paper puts forward four policy suggestions: Policy incentives, government functions, financial management and macro-control.
Under the background of “the Belt and Road” and “China-Mongolia-Russia economic corridor” initiatives, this paper studied the traffic dominance and its spatial pattern characteristics in Eastern Russia during 2005—2019. The evaluation of traffic dominance was conducted with three indicators, in other words, traffic network density, location advantage, traffic facility degree. The spatial differentiation of the traffic dominance, traffic network density, location advantage, and traffic facility degree was performed respectively by using ArcGIS. The results are as following. First, the comprehensive traffic scale and traffic capacity have decreased in Eastern Russia. Some traffic indicators have shown a tendency of attenuation backward in Eastern Russia. The construction, transformation and renewal of traffic facilities are very urgent and imminent in Eastern Russia. Second, the traffic dominance of eastern Russia has decreased, and the traffic dominance of most federal subjects is lower than the average level of all the federal subjects. Spatially, the traffic dominance in Siberian Federal District is higher than that of Far East Federal District, with the order of their traffic dominance as follows: Western Siberian Federal District> Eastern Siberian Federal District, and Southern Far East Federal District> Northern Far East Federal District. Third, the road network density has increased and the railway network has not changed in Eastern Russia. Spatially, the traffic network density of the Eastern Russia shows “High West, Low East” and “High South, Low North” spatial patterns. The location advantage of Siberian Federal District presents a “core-edge” pattern with Novosibirsk Region as the center and decreasing to the periphery. The location advantage of Far East Federal District shows a “core-edge” pattern with Khabarovsk Territory as the center and decreasing to the periphery. The traffic facility degree of Eastern Russia has decreased, showing a “High West, Low East” spatial pattern. Finally, the traffic dominance, traffic network density, location advantage, and traffic facility degree in Siberian Federal District are all higher than those of Far East Federal District. The areas with high levels are concentrated in Omsk Region, Novosibirsk Region, Altay Territory and Kemerovo Region. The areas with low ones are mostly in Kamchatka Territory, Magadan Region, Chukotka Autonomous Area, Republic of Altay and Republic of Tyva.
This article explored the connotation of settlement landscapes and ecological, living, and production landscape genes. The results show that: 1) Lhünzê Town and Rido Township form aggregation centers with a density of more than 0.46/km2, while other areas are scattered. The shape of the natural village patch is prolate and complex. 2) The choice of settlement location is largely dependent on the ecological view of Tibetan traditional culture and natural environment, resulting in three settlement location patterns have formed: river valley, gentle slope of the mountainside, and confluence of rivers. 3) Dispersed settlements are irregularly arranged around farmland and hills, forming a landscape where settlements blend harmoniously with the natural environment. Clustered settlements are typically located in river valleys or at the confluence of rivers, reflecting an ecological view that values the favorable orientation of hills and slopes for good geomancy. 4) Settlements and surrounding vegetation form a combination pattern of crops and settlements, and forests and settlements. 5) Settlements are built around temples for the convenience of daily religious activities of Tibetan people, while settlements built around administrative centers or transportation lines are for the convenience of residents’ services and travel. 6) The production genes of settlement landscapes include the unique land use imprint of forest and farmland. This study provides references for the optimization of settlement patterns and the improvement of human settlements in the Qinghai-Xizang Plateau.
The fear of crime is an important factor that reduces residents’ subjective well-being and life satisfaction. It is also an important research content in disciplines such as crime geography. According to differences in research perspectives, it can be divided into five aspects: psychological perspective, individual perspective, environmental perspective, daily activities perspective and crime prevention and control perspective, and has formed the victimization model, vulnerability model, disorder model, collective efficacy model and community policing model and other theoretical models. However, in terms of the impact of environment on fear of crime, existing research has mainly focused on the objective environment, and research on the subjective level of community environment perception is relatively weak. To this end, the research selected seventy-four typical communities in Guangzhou. A total of 1 568 questionnaires through household surveys were distributed to study the impact of community environment perception on fear of crime, including perception of environmental disorder, perception of collective efficacy and perception of social control. The results show that in addition to gender, age and crime victimization experience having a significant impact on fear of crime, community environment perception also has an important impact on fear of crime. Among them, the perception of disorder in the social environment and the perception of disorder in the physical environment have a significant positive effect on the fear of crime. The impact of collective efficacy perception on the fear of crime is not significant. Social control could be divided into two aspects, formal social control and informal social control. Formal social control has a significant inhibitory effect on fear of crime, while informal control has no significant effect on fear of crime.
The identification of ecological restoration areas in territorial space is a crucial aspect of the ongoing project for ecological protection and restoration, in order to implement the ideology of ecological civilization in the new era. Currently, research on ecological restoration areas in territorial space is mostly based on the identification of ecological security patterns, without sufficient consideration of regional characteristics. This paper incorporates ecological vulnerability assessment to improve the methodological framework for identifying ecological restoration areas in territorial space. Using the Wuhan metropolitan area as a case study, it explores new pathways for enhancing ecological environment protection in mega-city regions. The MSPA, MCR model, and circuit theory were employed to construct an ecological security pattern consisting of “ecological source-ecological corridor-ecological node”. Based on the VSD model, a comprehensive evaluation index system was established, with 16 influencing factors derived from nine levels including human activities, socio-economic factors, and natural conditions, focusing on exposure, sensitivity, and adaptive capacity. The ecological vulnerability of the study area in 2010 and 2018 was assessed. Finally, the ecological restoration areas were identified by integrating the results and targeted restoration and protection measures were proposed. 1) A total of 10 ecological source areas were identified, covering a total area of 14 761.9 km2. They were mainly distributed in the Yangtze River Basin, northeastern Huanggang City, and southeastern Huangshi City. There were 45 ecological corridors, including 17 important corridors and 28 general corridors. There were 19 ecological pinch-points and 7 ecological barriers, mainly concentrated in the northern, central, and southern parts of the Wuhan metropolitan area. 2) The ecological vulnerability of the study area showed potential fragility and mild fragility in both 2010 and 2018. The proportion of potential fragile areas decreased by 12.85%, while mild fragile areas increased by 4.49%. The proportion of extremely and highly fragile areas was relatively small, but it grew from 12.44% to 16.89%. Overall, the ecological environment was relatively favorable. 3) A total of four ecological restoration areas were identified, covering a total area of 3 779.7 km2. These areas include ecological landscape reshaping zones that require the creation of high-quality blue-green ecological spaces, integrated corridors zones that require coordinated implementation of ecological corridor construction along the routes, artificial restoration zones that require strengthened ecological restoration of industrial and mining abandoned lands, and industrial transformation zones that require a commitment to green development and industrial transformation. This study breaks through the previous practice of only relying on ecological security patterns for identifying ecological restoration areas. By incorporating ecological vulnerability assessment, the identification of ecological restoration areas in territorial space becomes more comprehensive. This contributes to the coordinated development of regional economy and ecological environment protection in metropolitan area.
Extreme disasters such as floods caused by climate change seriously affect the sustainable development of rural areas. This article focuses on the vulnerability of rural disasters, taking 418 villages or communities in Xun County, Henan Province as the research object. From three dimensions of exposure, sensitivity, and adaptability, an indicator system is constructed to comprehensively evaluate the vulnerability of rural areas under the impact of floods. Research shows that: 1) The average vulnerability of rural disasters in Junxian County are 0.47 (out of 1.00), which is at a lower than average level. The disaster exposure (0.72) and adaptability (0.76) are relatively high, while the sensitivity (0.45) is relatively low. There are spatial differences in disaster resilience performance among different townships. 2) Areas closer to rivers and with low-lying terrain naturally have higher exposure levels, and are more likely to suffer from flood impacts earlier than other areas, and tend to face greater disaster losses. At this point, a good early warning mechanism and preventive measures in the pre disaster stage can effectively reduce the vulnerability of rural disasters by improving adaptability. 3) When a flood occurs, the public is more inclined to protect personal property before the disaster poses a threat to personal safety. This is reflected in the fact that the proportion of understanding and responding measures in each township is generally higher than the proportion of actually following orders. At this point, on-site guidance plays an irreplaceable key role in the face of disaster impacts. Based on the above research results, the article proposes policy recommendations to reduce rural disaster vulnerability and enhance rural disaster resilience.
This paper takes the current land use situation in Jiangxi Province in 2010 and 2020 as the base period data, and combines the characteristics of natural resources and land use policies in Jiangxi Province, then it uses the PLUS model to simulate three future scenarios of land use in the province in 2030 (the normal development scenario, the ecological protection scenario, and the arable land protection scenario), discovering the connotation of the growth law and the mechanism of land transformation through the simulation analysis and evaluating the results of the three future development scenarios based on the concept of sustainable development. The results of the three future development scenarios were evaluated based on the concept of sustainable development. The results show that: 1) From 2010 to 2020, the main trends in land use in Jiangxi Province are a continuous decrease in farmland and forest area, and a stable increase in shrub and construction land area. During the land transformation process, the conversion between farmland, forest, and shrub land is prominent, with farmland and forest serving as the main sources of construction land expansion, and there is a substitution relationship between forest and farmland. 2) In the suitability assessment of the three future scenarios (2030), the normal development scenario shows consistent changes in area compared to the 2010—2020 period. It has the highest social and economic benefits, the largest suitability simulation index (SSI), and the best potential for sustainable development. Under the ecological protection scenario, the areas of shrub land, water bodies, and wetlands slightly increase, while farmland decreases significantly. Compared to the other two scenarios, it has the best ecological benefits and good suitability. Under the farmland protection scenario, farmland resources are replenished, forest area decreases sharply, and the areas of construction land and shrub land increase. It has the lowest economic benefits and moderate suitability. The multi-scenario simulations reflect the different development needs of Jiangxi Province, providing reference for managers in future land spatial planning and development.
The past millennium represents a critical period for global change research, yet there remains a lack of consensus on the temperature-humidity patterns and the driving mechanisms due to differences in research methodologies and proxy records. The Medieval Warm Period (MWP) and the Little Ice Age (LIA) are widely recognized as significant climate episodes during this time, but the temperature-humidity patterns associated with these periods vary regionally. In particular, the spatial differences and influencing factors in southwestern China remain understudied. The western Guizhou Plateau (WGP), situated in the northeast of the Yunnan-Guizhou Plateau within the hinterland of the Wumeng Mountains, is particularly sensitive to climate and environmental changes. The Yejiping peat, located in the subalpine karst region of the WGP and influenced by the southern branch of the westerlies, offers a highly detailed and continuous record of climate variability during the MWP and LIA. In this study, we measured the water content, loss on ignition (LOI), and carbonate content of sediments from the Yejiping peat core (YJP01). High-resolution, continuous X-ray fluorescence core scanning was utilized to determine the geochemical element content and chromaticity of the samples. By analyzing the activity, content, and ratios of geochemical elements, and applying multivariate statistical techniques such as cluster and correlation analyses, we identified the sources of the primary elements in the Yejiping peat sediments and their environmental implications. A robust chronological framework was established using high-density AMS14C dating, enabling us to reconstruct a detailed paleoclimate evolution from the MWP to the LIA on the WGP. This study also discusses the spatial patterns of climate variability during the MWP and LIA. Our results revealed the following key findings: 1) Multiple proxies from the Yejiping peat indicate that the climate was warm and humid during the MWP (
Using the observation data from 665 stations in May-September 1981—2019 in China and the precipitation grid data from the Global Precipitation Measurement (GPM) inversion, for 224 heavy precipitation events (daily precipitation exceeding 250 mm) at 97 stations in the eastern region, the deviation in the location of precipitation extremes and the precipitation amount in the ERA5-Land reanalysis data with 0.1 degree spatial resolution were counted. The results show that: 1) There are 123 cases (54.9% of the total cases) of heavy precipitation extreme centers in the rectangular area of 9×9 grid centered on the station, 45 cases (36.6%) of which have their fallout points located in the grid where the station is located and the adjacent grids, and 119 cases (96.7%) of which have their deviation within 4 grids, and the majority of the predicted precipitation extreme centers are within 40 km. In terms of orientation, the predominant deviation is toward the north (30.1%), indicating that most of the fallout deviation of the simulated extreme precipitation centers do not beyond the mesoscale range and tend to be northward; 2) Approximately 35% of the stations in the GPM inversion precipitation are located in the grid where the extreme center of heavy precipitation is located or in the adjacent grid, and the deviation from the ERA5-Land extreme center corresponding to the 68 heavy precipitation events with the existence of extreme centers are mainly concentrated within 4 grids (94.1% of the total) and mainly to the north (31.7% of the total); 3) If the precipitation is revised by considering the deviation of the location of the extreme center of heavy precipitation, it is able to reduce the ERA5-Land precipitation deviation by 37.7 mm(12.6%), which proves that considering the deviation of the location of heavy precipitation can further reduce the forecast error while taking into account the underestimation of simulated precipitation intensity. The uncertainty in the location of the heavy precipitation extremes is informative for the risk and warning areas of extreme precipitation events.
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.
To enhance the monitoring of compound drought and heatwave events (CDHEs), Inner Mongolia was selected as the study area. Based on data from 115 stations, the drought and heatwave events in this region were defined and identified using the Standardized Precipitation Evapotranspiration Index and the high-temperature relative threshold method. On this basis, a Compound Drought and Heatwave Magnitude Index (CDHMI) was constructed to statistically analyze the Compound Drought and Heatwave Frequency (CDHF), and then a study on the spatiotemporal variation characteristics of droughts, heatwaves, and CDHEs was carried out. The results show that during the warm season (May to October), the intensity of droughts at different time scales (1-month and 6-month scales) is increasing. The western part of Inner Mongolia and the central part of Tongliao City are prone to frequent droughts, and the frequency of droughts in the central and eastern regions has significantly increased. The frequency of heatwaves has significantly increased, and the period of heatwaves has been significantly extended, with the duration and intensity of heatwaves showing a non-significant increasing trend. The frequency, duration, and intensity of heatwaves generally show a spatial distribution pattern of being higher in the west and lower in the east. The frequency and intensity of CDHEs have shown a significant increasing trend, especially after 1998. Spatially, high values of CDHF are concentrated in the Xilingol League and Hulunbuir City, with a significant increase in CDHF in the northern region of Inner Mongolia, while high-intensity CDHMI is distributed in the northeastern and southwestern regions of Inner Mongolia, with a growth trend similar to that of CDHF.
