Wetlands offer important ecological functions and values.Wetland functional zoning provides a reference and basis for sustainable fulfilment and management.In this study,two coastal urban agglomerations in South China...Wetlands offer important ecological functions and values.Wetland functional zoning provides a reference and basis for sustainable fulfilment and management.In this study,two coastal urban agglomerations in South China were taken as study areas,namely,the Guangxi Beibu Gulf(GBG)and Guangdong-Hong Kong-Macao Greater Bay Area(GBA).Based on multisource information data,a wetland functional zoning system was constructed with the four levels of zoning concept,zoning principle,zoning basis,and zoning scheme.The functional zoning and dynamic analysis of wetlands from 1990 to 2020 were carried out from multiple perspectives of wetland ecological functions,wetland management and conservation functions.The results showed that:1)in terms of wetland ecological functions,the two coastal urban agglomerations were dominated by hydrological regulation and purification of environmental functional areas.The coastal region was largely characterized by the main functional areas of climate regulation and biodiversity maintenance.2)Regarding wetland management and conservation functions,two coastal urban agglomerations exhibited similar trends in terms of the sizes of their conservation and buffer zones from 1990 to 2020.Prevention and control zones were mainly located in core cities in a concentrated manner.Conservation zones largely comprised mountainous woodlands and important wetlands.3)The two coastal urban agglomerations could be divided into 21 wetland functional zones.The central river area has remained the main prevention and control zone for many years.Regarding conservation zones,ecological protection and restoration should be the main focus.Regarding buffer zones,the construction of wetlands and surrounding complex systems should be strengthened or enhanced.Regarding prevention and control zones,activities that do not affect wetland functions should be allowed,provided that they comply with existing laws and regulations.This study could provide technical support and practical application guidance for wetland regulation and management.展开更多
Land use change is a fundamental factor affecting ecosystem’s structures and functions.However,few studies have explored the ecological disturbance caused by land use change from a combined structural and functional ...Land use change is a fundamental factor affecting ecosystem’s structures and functions.However,few studies have explored the ecological disturbance caused by land use change from a combined structural and functional perspective.In this study,the ecological structural disturbance index(SDI)and functional disturbance index(FDI)were introduced to quantitatively evaluate ecological disturbance caused by land use change in a typical karst area—Huangping County,Guizhou Province,China during 2009–2019.Results show that although the area of ecological land increased during past 10 yr,there had been a fragmentation trend of ecological land.Agricultural occupation was more severe than construction encroachment on ecological land.The grids with negative structural disturbance were consistent with areas of obvious dynamic loss and gain of ecological land.Ecological fragmentation had a greater impact than habitat gain in grids with negative structural disturbance.The ecosystem service functions of supply,adjustment,support,and culture were obviously affected by land use change,and the total FDI reflects the trade-off among them.Negative FDI values were easily observed in the rocky desertification area or water and soil loss area.The combination analysis of the SDI and FDI indicated the characteristic of codirectional ecologically structural and functional disturbance in the majority of grids.The findings improve our understanding of multiple relationships among ecological disturbances and provide valuable information for guiding land use activities.展开更多
This study focuses on the three courtyards located in the eastern,central,and western sections of the Tongzhou Campus of Renmin University of China.Adopting a functional differentiation perspective,the research system...This study focuses on the three courtyards located in the eastern,central,and western sections of the Tongzhou Campus of Renmin University of China.Adopting a functional differentiation perspective,the research systematically analyzes the patterns of plant diversity within courtyards characterized by distinct functional orientations.This analysis employs various plant species diversity indices,including the Patrick richness index,Simpson dominance index,Shannon-Wiener diversity index,and Pielou evenness index,alongside a classification of functional plant types,namely ornamental,ecological regulation,spatial shaping,and recreational assistance.The results indicate that the east courtyard presents the highest Patrick species richness(S=42),predominantly comprising spatial shaping and recreational assistance plants,which are wellsuited for recreational and passage functions.Conversely,the central courtyard exhibits the lowest Patrick species richness(S=19),characterized by a balanced distribution of functional types,with an emphasis on public display and traffic guidance.The west courtyard demonstrates the greatest stability in the tree layer(D=0.87),featuring a combination of shade-tolerant and ornamental plants that fulfill the requirements for a tranquil and naturalistic environment.One-way analysis of variance reveals that only Patrick species richness differs significantly among the courtyards(P=0.007),whereas the diversity index does not show a significant difference.This finding suggests that functional requirements precisely regulate diversity through microhabitat heterogeneity and plant configuration strategies.This study offers both a theoretical foundation and practical guidance for the plant configuration and functional optimization of small-scale courtyards on campus.展开更多
To adapt to national climate change strategies,understanding the thermal vulnerability of urban functional zones(UFZs)is critical for enhancing the livability and sustainable development of cities.We address the limit...To adapt to national climate change strategies,understanding the thermal vulnerability of urban functional zones(UFZs)is critical for enhancing the livability and sustainable development of cities.We address the limitations of existing thermal vulnerability assessments by incorporating human perception into the analysis.Specifically,we introduce the sky openness index to reflect human perception of the thermal environment and examine variations in thermal vulnerability across different UFZs.Using the Extreme Gradient Boosting(XGBoost)-SHapley Additive exPlanations(SHAP)model,we analyze the contributions of 2D and 3D urban form indicators to thermal vulnerability and link these contributions to the unique needs and vulnerability characteristics of UFZs of Foshan City,China in 2023.The results reveal that:1)high-value heat-fragile areas(1.74–2.00]constitute 10.42%of Foshan City;2)traffic zone and publiccommercial zone exhibit the highest levels of thermal vulnerability;and 3)building height and the normalized building index are the most influential factors,with contributions of|0.06|and|0.03|,respectively.We provide a scientific foundation for developing governance strategies to promote urban resilience.展开更多
Northeast China is a unique place to study intra-plate volcanism. We analyzed P-wave receiver function data recorded by 111 permanent broadband seismic stations in Northeast China. The results show that the crustal th...Northeast China is a unique place to study intra-plate volcanism. We analyzed P-wave receiver function data recorded by 111 permanent broadband seismic stations in Northeast China. The results show that the crustal thickness varies from 27.9 km beneath the eastern flank of the Songliao Basin to 40.7 km beneath the Great Xing＇an Range region. The large depth variations of the Moho can be largely but not completely explained by surface topography. The residual Moho depth calculated based on the Airy＇s isostasy model indicates that the Moho is dynamically uplifted by 〈3 km beneath the eastern flank of the Songliao Basin and the Changbaishan region. We suggest that a mantle upwelling, which has been proposed by several recent seismic studies, might have caused the uplift.展开更多
The spatial structures of China’s Major Function Zoning are important constraining indicators in all types of spatial planning and key parameters for accurately downscaling major functions.Taking the proportion of ur...The spatial structures of China’s Major Function Zoning are important constraining indicators in all types of spatial planning and key parameters for accurately downscaling major functions.Taking the proportion of urbanization zones,agricultural development zones and ecological security zones as the basic parameter,this paper explores the spatial structures of major function zoning at different scales using spatial statistics,spatial modeling and landscape metrics methods.The results show:First,major function zones have spatial gradient structures,which are prominently represented by latitudinal and longitudinal gradients,a coastal distance gradient,and an eastern-central-western gradient.Second,the pole-axis system structure and core-periphery structure exist at provincial scales.The general principle of the pole-axis structure is that as one moves along the distance axis,the proportion of urbanization zones decreases and the proportion of ecological security zones increases.This also means that the proportion of different function zones has a ring-shaped spatial differentiation principle with distance from the core.Third,there is a spatial mosaic structure at the city and county scale.This spatial mosaic structure has features of both spatial heterogeneity,such as agglomeration and dispersion,as well as of mutual,adjacent topological correlation and spatial proximity.The results of this study contribute to scientific knowledge on major function zones and the principles of spatial organization,and it acts as an important reference for China’s integrated geographical zoning.展开更多
In China, rural settlements are usually multifunctional complex of natural societies and they also play important productive function. This study explored the spatiotemporal evolution of the productive function of thr...In China, rural settlements are usually multifunctional complex of natural societies and they also play important productive function. This study explored the spatiotemporal evolution of the productive function of three rural settlements, i.e.,Hetaoyuan, Dawengshan, and Gaoqiao, in the Yimeng Mountain in Shandong province of eastern China.Residents lived in this three types of rural settlements were all involved in agricultural production(i.e., grain threshing, drying and storage), which had remained dominant in Hetaoyuan. Dawengshan became an industrial-oriented settlement, while Gaoqiao became a commercial-oriented settlement. This evolution was reflected in the livelihood strategy changes of rural households and the transition of rural settlements changes. The choice of livelihood strategy was affected by the livelihood assets and policies, which resulted in the spatiotemporal evolution of the productive function of rural settlements. This study can provide references for the implementation and adjustment of rural residential land consolidation policies and the improvement of production and the quality of rural life in future.展开更多
We analyzed a total of 37 427 receiver-function data recorded by national and regional broadband seismic networks of the China Earthquake Administration to study the mantle transition zone beneath eastern and central ...We analyzed a total of 37 427 receiver-function data recorded by national and regional broadband seismic networks of the China Earthquake Administration to study the mantle transition zone beneath eastern and central China. Significant topography on both the 410-km and 660-km discontinuities was clearly imaged in the 3D volume of CCP （common-conversion-point） stacked images that cover an area of 102.5°F-122.5°E and 22.0°N-42.0°N. 3D crustal and mantle velocity models were used in computing the Ps time moveouts to better image the absolute depths of the two discontinuities. We found that the 660-km discontinuity is depressed up to 25 km along the east coast of China, indicating the presence of the subducted Pacific slab in the region. More interestingly, a double 660-km was observed beneath the Huanghai Sea, which was not seen from the 410-km discontinuity. We found a strong and localized anomaly beneath the Quaternary Datong volcano located at the northeastern edge of the Ordos Plateau in North China. The 410-km is depressed by as much as 15 km beneath the volcano. If the amount of the depression is caused by unmodeled low velocity anomaly in the upper mantle, it requires either a strong （4%-8%） localized low velocity anomaly near the lithosphere-asthenosphere boundary or -1.5% low velocity column across the entire upper mantle above the 410-km. The latter could suggest a deep origin of the Datong volcano, although it was usually attributed to edge-driven convection by most of the literatures.展开更多
Three types of spatial function zoning is an effective measure for regional environmental protection and orderly development.For ecological and economic coordinated development, spatial function zones should be divide...Three types of spatial function zoning is an effective measure for regional environmental protection and orderly development.For ecological and economic coordinated development, spatial function zones should be divided scientifically to clear its direction of development and protection. Therefore, based on ecological constraints, a beneficial discussion would be about the key ecological function areas adopting the concept of ecological protection restriction and supporting socioeconomic development for spatial function zoning. In this paper, the researchers, taking Tacheng Basin, Xinjiang of China as an example, choose township as basic research unit and set up an evaluation index system from three aspects, namely, ecological protection suitability, agricultural production suitability, and urban development suitability, which are analyzed by using spatial analysis functions and exclusive matrix method. The results showed that: 1) This paper formed a set of multilevel evaluation index systems for three types of spatial function zoning of the key ecological function areas based on a novel perspective by scientifically dividing Tacheng Basin into ecological space, agricultural space, and urban space,which realized the integration and scientific orientation for spatial function at the township scale. 2) Under the guidance of three types of spatial pattern, the functional orientation and suggestions of development and protection was clearly defined for ecological protection zones,ecological economic zones, agricultural production zones, and urban development zones. 3) A new idea of space governance is provided to promote the coordinated and sustainable development between ecology and economy, which can break the traditional mode of thinking about regional economic development, and offers a scientific basis and reference for macro decision-making.展开更多
Newest planning methods implemented by Chinese government are promoting a coordinated regional development and shaping an orderly spatial structure by applying the regulation of territorial function. This article anal...Newest planning methods implemented by Chinese government are promoting a coordinated regional development and shaping an orderly spatial structure by applying the regulation of territorial function. This article analyzes the problems of spatial planning and regional strategy caused by the wrongly-set primary goal of economic development; it states that the three-fold objective of competitiveness, sustainability, and welfare fairness shall be the principal for China to implement the spatial regulation in the new era; it discusses about theoretical thoughts and technology framework of conducting the ′Major Function Oriented Zone′ based on their different major functions that each region plays in urbanization and industrialization, ecological constructions, grain productions, and protection of natural and cultural heritages; it introduces the new concept of ′Major Function Oriented Zone′ that include the major functions category, the stereo regional equilibrium mode, the two-level zoning specification, and the territorial development intensity; it offers a zoning scheme that defines development-optimized and development-prioritized zones as regions with massive urbanization and industrialization, development-restricted zones as ecological constructing or grain producing regions, development-prohibited zones as natural and cultural heritage protecting regions; and finally it addresses the main obstacle for implementing ′Major Function Oriented Zone′, which is the institutional arrangement of the supreme goal of high GDP growth rate that is currently being implemented.展开更多
P-wave and S-wave receiver function analyses have been performed along a profile consisted of 27 broadband seismic stations to image the crustal and upper mantle discontinuities across Northeast China. The results sho...P-wave and S-wave receiver function analyses have been performed along a profile consisted of 27 broadband seismic stations to image the crustal and upper mantle discontinuities across Northeast China. The results show that the average Moho depth varies from about 37 km beneath the Daxing＇anling orogenic belt in the west to about 33 km beneath the Songliao Basin, and to about 35 km beneath the Changbai mountain region in the east. Our results reveal that the Moho is generally flat beneath the Daxing＇anling region and a remarkable Moho offset （about 4 km） exists beneath the basin-mountain boundary, the Daxing＇anling-Taihang Gravity Line. Beneath the Tanlu faults zone, which seperates the Songliao Basin and Changbai region, the Moho is uplift and the crustal thick- ness changes rapidly. We interpret this feature as that the Tanlu faults might deeply penetrate into the upper mantle, and facilitate the mantle upwelling along the faults during the Cenozoic era. The average depth of the lithosphereasthenosphere boundary （LAB） is - 80 km along the profile which is thinner than an average thickness of a continental lithosphere. The LAB shows an arc-like shape in the basin, with the shallowest part approximately beneath the center of the basin. The uplift LAB beneath the basin might be related to the extensive lithospheric stretching in the Mesozoic. In the mantle transition zone, a structurally complicated 660 km discontinuity with a maximum 35 km depression beneath the Changbai region is observed. The 35 km depression is roughly coincident with the location of the stagnant western pacific slab on top of the 660 km discontinuity revealed by the recent P wave tomography.展开更多
As the population continues to shrink in the black soil region of Northeast China since 2000,it is critical to master the impact of population shrinkage on rural functions to realize rural revitalization and sustainab...As the population continues to shrink in the black soil region of Northeast China since 2000,it is critical to master the impact of population shrinkage on rural functions to realize rural revitalization and sustainable development.In this study,we focused on the impacts of depopulation on the evolution and interrelationship of rural subfunctions.Based on the rural function indexes system,the TOPSIS(Technique for Order Preference by Similarity to an Ideal Solution)method,spatial analysis method,and mathematical statistics analysis method were used to summarize the spatial and temporal characteristics of rural function development,as well as the effect of population shrinkage in the typical black soil region of Northeast China.The results showed that depopulation varied in the extent and duration between the forested region and plain areas,which both impacted the trajectories of rural subfunctions evolution.For the economic development function and ecological conservation function,the effect of continuous slight depopulation was beneficial,while the effect of rapid depopulation was adverse,which was exactly opposite to the agricultural production function.All forms of population shrinkage were conducive to the development of the social security function.With the deepening population shrinkage,depopulation mainly promoted the collaborative development between subfunctions in this study,except the relationship between agricultural production and social security function.But effects of depopulation on the interrelationship of rural subfunctions varied between the forested region and plain areas in some cases.The results provided evidence for the cognition that population shrinkage had complicated effects on rural subfunctions.展开更多
To solve the problems caused by irrational land-use, studying the functions of land-use, its changing characteristics, and the relationship between each land-use function will be beneficial for achieving sustainable l...To solve the problems caused by irrational land-use, studying the functions of land-use, its changing characteristics, and the relationship between each land-use function will be beneficial for achieving sustainable land development. In this research, we constructed an evaluation framework of multiple land-use functions(LUFs) based on sustainable land-use theory. Specifically,, we classified the multiple LUFs into three types: agricultural production function(APF), living function(LVF), and ecological service function(ESF).We then spatialized the economic and social data, and implemented the InVEST(Integrated Valuation of Ecosystem Services and Tradeoffs) model and RUSLE(Revised Universal Soil Loss Equation) model to evaluate each sub-LUF(crop production, aquatic production, woodlands production, livestock production, living space, life quality, water supply, soil conservation, climate regulation, biological conservation) in central China in 2000 and again in 2015. Moreover, by analyzing the changes to LUFs and the relationships between each LUF change, we were able to discern patterns of LUF change in central China. The results show that: (1)42.12% of total territory in the study area increased their APF from 2000 to 2015, while 43.41% of the lands increased their ESF yet only 8.98% of the lands increased their LVF;(2) in Hubei and Hunan, there was more land with an increase of APF than in Anhui or Jiangxi. The APF in Jiangxi exhibited the greatest decline over time period, the LVF increased more in the provincial capital cities than in other regions, and the ESF expanded more in Jiangxi than in the other provinces;and (3) the changes in APF were significantly and positively correlated with changes in LVF. Additionally, changes in ESF were negatively but non-significantly correlated with changes in APF and LVF.展开更多
ABSTRACT: According to preliminary statistics, there are 9. 4 ×106ha of mire, 8. 0 × 106ha of lake, 2. 1 × 106ha of salt marsh, 2.1 × 107ha of shallow sea (0 - 5m), and 3. 8 × 107ha of paddyfi...ABSTRACT: According to preliminary statistics, there are 9. 4 ×106ha of mire, 8. 0 × 106ha of lake, 2. 1 × 106ha of salt marsh, 2.1 × 107ha of shallow sea (0 - 5m), and 3. 8 × 107ha of paddyfield, their total area amounts to 8. 45× 107ha. Wetland consists of natural wetland system and man-made wetland system. According to hydrology, landform, soil and vegetation etc., natural wetland can be divided into the following types: marine, esturine, riverine, lacustrine, palustrine subsystems. On the basis of the wetland bottom compound, waterlogged state and vegetation forms, it can be subdivided into 26 wetland classes. Man-made wetland can be subdivided into 4 wetland classes. Wetland is a unique landscape in the earth and one of the most important living environment with rich resources and many functions. At present, 262 different types of Wetland Natural Reserves have been established in China, in which 7 Wetland Nature Reserves have been listed in international important wetlands of The Wetland展开更多
We produced and analyzed oasis structure information, and evaluated oasis functional stability using the multiple indicators based on Remote Sensing(RS) and Geographical Information System(GIS) in the arid region of C...We produced and analyzed oasis structure information, and evaluated oasis functional stability using the multiple indicators based on Remote Sensing(RS) and Geographical Information System(GIS) in the arid region of China in 2015. The results showed that the oases area was 193,734 km^2, accounting for 8.17% of the arid region of China. The spatial difference in the functional stability of oases was obvious. The Beijiang zone had the highest functional stability and was relatively stable state, and the Hexi Corridor-Alashan Plateau zone had the lowest functional stability and was relatively unstable. The functional stability is dominated by production and ecological functions, which have regional differences. Increasing oasis agricultural output, strengthening highway infrastructure construction and paying attention to education will become important ways to improve oasis functional stability. Water resources determine the ecological function, thus affecting the oasis functional stability. The results provide references for the formulation of related policies according to local conditions.展开更多
This study presents an analysis of the spectral characteristics of remote sensing reflectance(Rrs)in northwestern South China Sea based on the in situ optical and water quality data for August 2018.Rrswas initially di...This study presents an analysis of the spectral characteristics of remote sensing reflectance(Rrs)in northwestern South China Sea based on the in situ optical and water quality data for August 2018.Rrswas initially divided into four classes,classes A to D,using the max-classification algorithm,and the spectral properties of whole Rrs were characterized using the empirical orthogonal function(EOF)analysis.Subsequently,the dominant factors in each EOF mode were determined.The results indicated that more than 95%of the variances of Rrs are partly driven by the back-scattering characteristics of the suspended matter.The initial two EOF modes were well correlated with the total suspended matter and back-scattering coefficient.Furthermore,the first EOF modes of the four classes of Rrs(A-D Rrs-EOF1)significantly contributed to the total variances of each Rrs class.In addition,the correlation coefficients between the amplitude factors of class A-D Rrs-EOF1 and the variances of the relevant water quality and optical parameters were better than those of the unclassified ones.The spectral shape of class ARrs-EOF1 was governed by the absorption characteristic of chlorophyll a and colored dissolved organic matter(CDOM).The spectral shape of class B Rrs-EOF1 was governed by the absorption characteristic of CDOM since it exhibited a high correlation with the absorption coefficient of CDOM(ag(λ)),whereas the spectral shape of class C Rrs-EOF1 was governed by the back-scattering characteristics but not affected by the suspended matter.The spectral shape of class D Rrs-EOF1 exhibited a relatively good correlation with all the water quality parameters,which played a significant role in deciding its spectral shape.展开更多
We sought to identify the differences between adolescents left behind in their home villages/towns(LBA)and non-left behind adolescents(NLB)on subjective well-being and family functioning due to parental migration in s...We sought to identify the differences between adolescents left behind in their home villages/towns(LBA)and non-left behind adolescents(NLB)on subjective well-being and family functioning due to parental migration in south China.We used a stratified cluster sampling method to recruit middle school students in a city experiencing population-emigration in Jiangxi Province in 2010.Participants included adolescents from families with:(1)one migrant parent,(2)both parents who migrated,or(3)non-left behind adolescents(i.e.,no migrant parent).To determine predictors of subjective well-being,we used structural equation models.Adolescents left behind by both parents(LBB)were less likely to express life satisfaction(P=0.038)in terms of their environments(P=0.011)compared with NLB.A parent or parents who migrated predicts lower subjective well-being of adolescents(P=0.051)and also lower academic performance.Being apart from their parents may affect family functioning negatively from an adolescent's viewpoint.Given the hundreds of millions of persons in China,many who are parents,migrating for work,there may be mental health challenges in some of the adolescents left behind.展开更多
The North China Craton(NCC)is one of the oldest cratons on earth.Several important tectonic transformations of MesozoicCenozoic tectonic regime led to the destruction of the North China craton.The knowledge of crustal...The North China Craton(NCC)is one of the oldest cratons on earth.Several important tectonic transformations of MesozoicCenozoic tectonic regime led to the destruction of the North China craton.The knowledge of crustal structure can provide important constraints for the formation and evolution of cratons.New maps of sediment thickness,crustal thickness(H)and v_(P)/v_(S)(κ)in the central and western NCC were obtained using sequential H-κstacking.P-wave receiver functions are calculated using teleseismic waveform data recorded by 405 stations from Chin Array project.Benefiting from the densely distribution of temporary seismic stations,our results reveal details of the crustal structure in the study area.The thickness of sedimentary layer in North China ranges from 0–6.4 km,and the thickest sedimentary layer is in Ordos block and its surroundings(about 2.8–6 km);The thickness of sedimentary layer in the Mongolia fold belt and Yinshan orogenic belt is relatively thin(less than 1 km).The crustal thickness of the study area varies between 27–48 km,of which the crust of the North China Plain is about 30–33 km,the central NCC is about 33–40 km,and the Ordos block is 40–48 km thick.The average v_(P)/v_(S)ratios in the study area is mostly between 1.66 and 1.90,and that in the Yanshan-Taihang mountain fold belt is between 1.70 and 1.85,and that in the Ordos block is between 1.65 and 1.90,with an average value of 1.77,indicating the absence of a thick basaltic lower crust.The obvious negative correlation between crustal thickness and average v_(P)/v_(S)ratio within Ordos and Central Asia orogenic belt may be related to magmatic underplating during the crustal formation.There is no significant correlation between the crustal thickness and the v_(P)/v_(S)ratio in the Lüliang-Taihang mountain fold belt,which may be related to the multiple geological processes such as underplating and crustal extension and thinning in this area.The lack of correlation between crust thickness and topography in the central orogenic belt and the North China Basin indicates the topography of these areas are controlled not only by crustal isostatic adjustment but also by the lithospheric mantle processes.展开更多
Since the reform and opening up,China's market-oriented agricultural management reform has achieved remarkable results,but the reform has not yet been put in place,and there are some flaws in some areas of reform....Since the reform and opening up,China's market-oriented agricultural management reform has achieved remarkable results,but the reform has not yet been put in place,and there are some flaws in some areas of reform.To deepen the reform of government's agricultural management reform under the new situation,it is necessary to further define the boundary between government and market on the basis of following the general rules of world's agricultural development and considering China's special situation of agriculture,nail down the scope of government functions,pinpoint the key areas of reform,and actively promote the rapid development of China's characteristic modern agriculture.展开更多
China had implemented the national strategies for Major Function-oriented Zones （MFOZs） to realize the goal of national sustainable development since 2010. This study analyzed and compared spatio-temporal characteri...China had implemented the national strategies for Major Function-oriented Zones （MFOZs） to realize the goal of national sustainable development since 2010. This study analyzed and compared spatio-temporal characteristics and differences in built-up area for China＇s MFOZs using a China＇ s Land Use Database （CLUD） derived from high-resolution remotely sensed images in the periods of 2000-2010 and 2010-2013. To sum up： （1） The percentage of built-up area in each of the MFOZs was significantly different, revealing the gradient feature of national land development based on the distribution of the main functions. （2） Annual growth in built-up area in optimal development zones （ODZs） decreased signifi- cantly during 2010-2013 compared with the period 2000-2010, while annual growth in built-up area in key development zones （KDZs）, agricultural production zones （APZs） and key ecological function zones （KEFZs） increased significantly. （3） In ODZs, the average annual increase in built-up area in the Yangtze River Delta region was significantly higher than in other regions; the average area increase and rate of increase of built-up area in KDZs was faster in the western region than in other regions; average annual area growth of built-up area in APZs in the northeast, central and western regions was twice as high as the previous decade on average; the annual rate of change and increase in the dynamic degree of built-up area were most notable in KEFZs in the central region. （4） The spatial pattern and charac- teristics of built-up area expansions in the period 2010-2013 reflected the gradient feature of the plan for MFOZs. But the rate of increase locally in built-up area in ODZs, APZs and KEFZs is fast, so the effective measures must be adopted in the implementation of national and regional policies. The conclusions indicated these methods and results were meaningful for future regulation strategies in optimizing national land development in China.展开更多
基金Under the auspices of National Natural Science Foundation of China(No.U21A2022,U1901219,42101369)National Key Research and Development Program of China(No.2023YFF0807204)。
文摘Wetlands offer important ecological functions and values.Wetland functional zoning provides a reference and basis for sustainable fulfilment and management.In this study,two coastal urban agglomerations in South China were taken as study areas,namely,the Guangxi Beibu Gulf(GBG)and Guangdong-Hong Kong-Macao Greater Bay Area(GBA).Based on multisource information data,a wetland functional zoning system was constructed with the four levels of zoning concept,zoning principle,zoning basis,and zoning scheme.The functional zoning and dynamic analysis of wetlands from 1990 to 2020 were carried out from multiple perspectives of wetland ecological functions,wetland management and conservation functions.The results showed that:1)in terms of wetland ecological functions,the two coastal urban agglomerations were dominated by hydrological regulation and purification of environmental functional areas.The coastal region was largely characterized by the main functional areas of climate regulation and biodiversity maintenance.2)Regarding wetland management and conservation functions,two coastal urban agglomerations exhibited similar trends in terms of the sizes of their conservation and buffer zones from 1990 to 2020.Prevention and control zones were mainly located in core cities in a concentrated manner.Conservation zones largely comprised mountainous woodlands and important wetlands.3)The two coastal urban agglomerations could be divided into 21 wetland functional zones.The central river area has remained the main prevention and control zone for many years.Regarding conservation zones,ecological protection and restoration should be the main focus.Regarding buffer zones,the construction of wetlands and surrounding complex systems should be strengthened or enhanced.Regarding prevention and control zones,activities that do not affect wetland functions should be allowed,provided that they comply with existing laws and regulations.This study could provide technical support and practical application guidance for wetland regulation and management.
基金Under the auspices of the National Natural Science Foundation of China(No.41661088,32101593,42361028)Science and Technology Program of Guizhou Province(No.Qiankehe Zhongyindi[2023]005)+1 种基金2024 Humanities and Social Science Research Project of Guizhou Provincial Department of Education(No.24RWZX007)Graduate Research Fund Project of Guizhou Province(No.2024YJSKYJJ153)。
文摘Land use change is a fundamental factor affecting ecosystem’s structures and functions.However,few studies have explored the ecological disturbance caused by land use change from a combined structural and functional perspective.In this study,the ecological structural disturbance index(SDI)and functional disturbance index(FDI)were introduced to quantitatively evaluate ecological disturbance caused by land use change in a typical karst area—Huangping County,Guizhou Province,China during 2009–2019.Results show that although the area of ecological land increased during past 10 yr,there had been a fragmentation trend of ecological land.Agricultural occupation was more severe than construction encroachment on ecological land.The grids with negative structural disturbance were consistent with areas of obvious dynamic loss and gain of ecological land.Ecological fragmentation had a greater impact than habitat gain in grids with negative structural disturbance.The ecosystem service functions of supply,adjustment,support,and culture were obviously affected by land use change,and the total FDI reflects the trade-off among them.Negative FDI values were easily observed in the rocky desertification area or water and soil loss area.The combination analysis of the SDI and FDI indicated the characteristic of codirectional ecologically structural and functional disturbance in the majority of grids.The findings improve our understanding of multiple relationships among ecological disturbances and provide valuable information for guiding land use activities.
基金Sponsored by 2025 Undergraduate Innovation and Entrepreneurship Training Program Project.
文摘This study focuses on the three courtyards located in the eastern,central,and western sections of the Tongzhou Campus of Renmin University of China.Adopting a functional differentiation perspective,the research systematically analyzes the patterns of plant diversity within courtyards characterized by distinct functional orientations.This analysis employs various plant species diversity indices,including the Patrick richness index,Simpson dominance index,Shannon-Wiener diversity index,and Pielou evenness index,alongside a classification of functional plant types,namely ornamental,ecological regulation,spatial shaping,and recreational assistance.The results indicate that the east courtyard presents the highest Patrick species richness(S=42),predominantly comprising spatial shaping and recreational assistance plants,which are wellsuited for recreational and passage functions.Conversely,the central courtyard exhibits the lowest Patrick species richness(S=19),characterized by a balanced distribution of functional types,with an emphasis on public display and traffic guidance.The west courtyard demonstrates the greatest stability in the tree layer(D=0.87),featuring a combination of shade-tolerant and ornamental plants that fulfill the requirements for a tranquil and naturalistic environment.One-way analysis of variance reveals that only Patrick species richness differs significantly among the courtyards(P=0.007),whereas the diversity index does not show a significant difference.This finding suggests that functional requirements precisely regulate diversity through microhabitat heterogeneity and plant configuration strategies.This study offers both a theoretical foundation and practical guidance for the plant configuration and functional optimization of small-scale courtyards on campus.
基金Under the auspices of Liaoning Revitalization Talents Program(No.XLYC2202024)Basic Scientific Research Project(Key Project)of the Education Department of Liaoning Province(No.LJ212410165084)the Fundamental Research Funds for the Central Universities(No.N2111003,N2411001)。
文摘To adapt to national climate change strategies,understanding the thermal vulnerability of urban functional zones(UFZs)is critical for enhancing the livability and sustainable development of cities.We address the limitations of existing thermal vulnerability assessments by incorporating human perception into the analysis.Specifically,we introduce the sky openness index to reflect human perception of the thermal environment and examine variations in thermal vulnerability across different UFZs.Using the Extreme Gradient Boosting(XGBoost)-SHapley Additive exPlanations(SHAP)model,we analyze the contributions of 2D and 3D urban form indicators to thermal vulnerability and link these contributions to the unique needs and vulnerability characteristics of UFZs of Foshan City,China in 2023.The results reveal that:1)high-value heat-fragile areas(1.74–2.00]constitute 10.42%of Foshan City;2)traffic zone and publiccommercial zone exhibit the highest levels of thermal vulnerability;and 3)building height and the normalized building index are the most influential factors,with contributions of|0.06|and|0.03|,respectively.We provide a scientific foundation for developing governance strategies to promote urban resilience.
文摘Northeast China is a unique place to study intra-plate volcanism. We analyzed P-wave receiver function data recorded by 111 permanent broadband seismic stations in Northeast China. The results show that the crustal thickness varies from 27.9 km beneath the eastern flank of the Songliao Basin to 40.7 km beneath the Great Xing＇an Range region. The large depth variations of the Moho can be largely but not completely explained by surface topography. The residual Moho depth calculated based on the Airy＇s isostasy model indicates that the Moho is dynamically uplifted by 〈3 km beneath the eastern flank of the Songliao Basin and the Changbaishan region. We suggest that a mantle upwelling, which has been proposed by several recent seismic studies, might have caused the uplift.
基金National Natural Science Foundation of China,No.41630644Innovative Think-tank Foundation for Young Scientists of China Association for Science and Technology,No.DXB-ZKQN-2017-048。
文摘The spatial structures of China’s Major Function Zoning are important constraining indicators in all types of spatial planning and key parameters for accurately downscaling major functions.Taking the proportion of urbanization zones,agricultural development zones and ecological security zones as the basic parameter,this paper explores the spatial structures of major function zoning at different scales using spatial statistics,spatial modeling and landscape metrics methods.The results show:First,major function zones have spatial gradient structures,which are prominently represented by latitudinal and longitudinal gradients,a coastal distance gradient,and an eastern-central-western gradient.Second,the pole-axis system structure and core-periphery structure exist at provincial scales.The general principle of the pole-axis structure is that as one moves along the distance axis,the proportion of urbanization zones decreases and the proportion of ecological security zones increases.This also means that the proportion of different function zones has a ring-shaped spatial differentiation principle with distance from the core.Third,there is a spatial mosaic structure at the city and county scale.This spatial mosaic structure has features of both spatial heterogeneity,such as agglomeration and dispersion,as well as of mutual,adjacent topological correlation and spatial proximity.The results of this study contribute to scientific knowledge on major function zones and the principles of spatial organization,and it acts as an important reference for China’s integrated geographical zoning.
基金supported by the National Natural Science Foundation of China(Grant Nos.41671519 and 41771560)
文摘In China, rural settlements are usually multifunctional complex of natural societies and they also play important productive function. This study explored the spatiotemporal evolution of the productive function of three rural settlements, i.e.,Hetaoyuan, Dawengshan, and Gaoqiao, in the Yimeng Mountain in Shandong province of eastern China.Residents lived in this three types of rural settlements were all involved in agricultural production(i.e., grain threshing, drying and storage), which had remained dominant in Hetaoyuan. Dawengshan became an industrial-oriented settlement, while Gaoqiao became a commercial-oriented settlement. This evolution was reflected in the livelihood strategy changes of rural households and the transition of rural settlements changes. The choice of livelihood strategy was affected by the livelihood assets and policies, which resulted in the spatiotemporal evolution of the productive function of rural settlements. This study can provide references for the implementation and adjustment of rural residential land consolidation policies and the improvement of production and the quality of rural life in future.
文摘We analyzed a total of 37 427 receiver-function data recorded by national and regional broadband seismic networks of the China Earthquake Administration to study the mantle transition zone beneath eastern and central China. Significant topography on both the 410-km and 660-km discontinuities was clearly imaged in the 3D volume of CCP （common-conversion-point） stacked images that cover an area of 102.5°F-122.5°E and 22.0°N-42.0°N. 3D crustal and mantle velocity models were used in computing the Ps time moveouts to better image the absolute depths of the two discontinuities. We found that the 660-km discontinuity is depressed up to 25 km along the east coast of China, indicating the presence of the subducted Pacific slab in the region. More interestingly, a double 660-km was observed beneath the Huanghai Sea, which was not seen from the 410-km discontinuity. We found a strong and localized anomaly beneath the Quaternary Datong volcano located at the northeastern edge of the Ordos Plateau in North China. The 410-km is depressed by as much as 15 km beneath the volcano. If the amount of the depression is caused by unmodeled low velocity anomaly in the upper mantle, it requires either a strong （4%-8%） localized low velocity anomaly near the lithosphere-asthenosphere boundary or -1.5% low velocity column across the entire upper mantle above the 410-km. The latter could suggest a deep origin of the Datong volcano, although it was usually attributed to edge-driven convection by most of the literatures.
基金Under the auspices of Grant Program of Clean Development Mechanism Fund of China(CDMF)(No.2014092)Task 2 of Key Service Project 5 for the Characteristic Institute of Chinese Academy of Sciences(No.TSS-2015-014-FW-5-2)+2 种基金National Natural Science Foundation of China(No.41571159)The Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA20010301)Jiangsu Natural Science Foundation(No.BK20181105)
文摘Three types of spatial function zoning is an effective measure for regional environmental protection and orderly development.For ecological and economic coordinated development, spatial function zones should be divided scientifically to clear its direction of development and protection. Therefore, based on ecological constraints, a beneficial discussion would be about the key ecological function areas adopting the concept of ecological protection restriction and supporting socioeconomic development for spatial function zoning. In this paper, the researchers, taking Tacheng Basin, Xinjiang of China as an example, choose township as basic research unit and set up an evaluation index system from three aspects, namely, ecological protection suitability, agricultural production suitability, and urban development suitability, which are analyzed by using spatial analysis functions and exclusive matrix method. The results showed that: 1) This paper formed a set of multilevel evaluation index systems for three types of spatial function zoning of the key ecological function areas based on a novel perspective by scientifically dividing Tacheng Basin into ecological space, agricultural space, and urban space,which realized the integration and scientific orientation for spatial function at the township scale. 2) Under the guidance of three types of spatial pattern, the functional orientation and suggestions of development and protection was clearly defined for ecological protection zones,ecological economic zones, agricultural production zones, and urban development zones. 3) A new idea of space governance is provided to promote the coordinated and sustainable development between ecology and economy, which can break the traditional mode of thinking about regional economic development, and offers a scientific basis and reference for macro decision-making.
基金Under the auspices of Key Project of National Natural Science Foundation of China (No. 40830741)National Key Technology R&D Program (No. 2008BAH31B01)
文摘Newest planning methods implemented by Chinese government are promoting a coordinated regional development and shaping an orderly spatial structure by applying the regulation of territorial function. This article analyzes the problems of spatial planning and regional strategy caused by the wrongly-set primary goal of economic development; it states that the three-fold objective of competitiveness, sustainability, and welfare fairness shall be the principal for China to implement the spatial regulation in the new era; it discusses about theoretical thoughts and technology framework of conducting the ′Major Function Oriented Zone′ based on their different major functions that each region plays in urbanization and industrialization, ecological constructions, grain productions, and protection of natural and cultural heritages; it introduces the new concept of ′Major Function Oriented Zone′ that include the major functions category, the stereo regional equilibrium mode, the two-level zoning specification, and the territorial development intensity; it offers a zoning scheme that defines development-optimized and development-prioritized zones as regions with massive urbanization and industrialization, development-restricted zones as ecological constructing or grain producing regions, development-prohibited zones as natural and cultural heritage protecting regions; and finally it addresses the main obstacle for implementing ′Major Function Oriented Zone′, which is the institutional arrangement of the supreme goal of high GDP growth rate that is currently being implemented.
文摘P-wave and S-wave receiver function analyses have been performed along a profile consisted of 27 broadband seismic stations to image the crustal and upper mantle discontinuities across Northeast China. The results show that the average Moho depth varies from about 37 km beneath the Daxing＇anling orogenic belt in the west to about 33 km beneath the Songliao Basin, and to about 35 km beneath the Changbai mountain region in the east. Our results reveal that the Moho is generally flat beneath the Daxing＇anling region and a remarkable Moho offset （about 4 km） exists beneath the basin-mountain boundary, the Daxing＇anling-Taihang Gravity Line. Beneath the Tanlu faults zone, which seperates the Songliao Basin and Changbai region, the Moho is uplift and the crustal thick- ness changes rapidly. We interpret this feature as that the Tanlu faults might deeply penetrate into the upper mantle, and facilitate the mantle upwelling along the faults during the Cenozoic era. The average depth of the lithosphereasthenosphere boundary （LAB） is - 80 km along the profile which is thinner than an average thickness of a continental lithosphere. The LAB shows an arc-like shape in the basin, with the shallowest part approximately beneath the center of the basin. The uplift LAB beneath the basin might be related to the extensive lithospheric stretching in the Mesozoic. In the mantle transition zone, a structurally complicated 660 km discontinuity with a maximum 35 km depression beneath the Changbai region is observed. The 35 km depression is roughly coincident with the location of the stagnant western pacific slab on top of the 660 km discontinuity revealed by the recent P wave tomography.
基金Under the auspices of China Postdoctoral Science Foundation(No.2022M713130)National Natural Science Foundation of China(No.42101212)Strategic Pilot Science and Technology Project of the Chinese Academy of Sciences(No.XDA28020403)。
文摘As the population continues to shrink in the black soil region of Northeast China since 2000,it is critical to master the impact of population shrinkage on rural functions to realize rural revitalization and sustainable development.In this study,we focused on the impacts of depopulation on the evolution and interrelationship of rural subfunctions.Based on the rural function indexes system,the TOPSIS(Technique for Order Preference by Similarity to an Ideal Solution)method,spatial analysis method,and mathematical statistics analysis method were used to summarize the spatial and temporal characteristics of rural function development,as well as the effect of population shrinkage in the typical black soil region of Northeast China.The results showed that depopulation varied in the extent and duration between the forested region and plain areas,which both impacted the trajectories of rural subfunctions evolution.For the economic development function and ecological conservation function,the effect of continuous slight depopulation was beneficial,while the effect of rapid depopulation was adverse,which was exactly opposite to the agricultural production function.All forms of population shrinkage were conducive to the development of the social security function.With the deepening population shrinkage,depopulation mainly promoted the collaborative development between subfunctions in this study,except the relationship between agricultural production and social security function.But effects of depopulation on the interrelationship of rural subfunctions varied between the forested region and plain areas in some cases.The results provided evidence for the cognition that population shrinkage had complicated effects on rural subfunctions.
基金Under the auspices of National Natural Science Foundation of China(No.41271534)China Scholarship Council(No.201906770044)。
文摘To solve the problems caused by irrational land-use, studying the functions of land-use, its changing characteristics, and the relationship between each land-use function will be beneficial for achieving sustainable land development. In this research, we constructed an evaluation framework of multiple land-use functions(LUFs) based on sustainable land-use theory. Specifically,, we classified the multiple LUFs into three types: agricultural production function(APF), living function(LVF), and ecological service function(ESF).We then spatialized the economic and social data, and implemented the InVEST(Integrated Valuation of Ecosystem Services and Tradeoffs) model and RUSLE(Revised Universal Soil Loss Equation) model to evaluate each sub-LUF(crop production, aquatic production, woodlands production, livestock production, living space, life quality, water supply, soil conservation, climate regulation, biological conservation) in central China in 2000 and again in 2015. Moreover, by analyzing the changes to LUFs and the relationships between each LUF change, we were able to discern patterns of LUF change in central China. The results show that: (1)42.12% of total territory in the study area increased their APF from 2000 to 2015, while 43.41% of the lands increased their ESF yet only 8.98% of the lands increased their LVF;(2) in Hubei and Hunan, there was more land with an increase of APF than in Anhui or Jiangxi. The APF in Jiangxi exhibited the greatest decline over time period, the LVF increased more in the provincial capital cities than in other regions, and the ESF expanded more in Jiangxi than in the other provinces;and (3) the changes in APF were significantly and positively correlated with changes in LVF. Additionally, changes in ESF were negatively but non-significantly correlated with changes in APF and LVF.
基金Under the auspices of the important B items of the Chinese Academy of Sciences(KZ951-B1-201).
文摘ABSTRACT: According to preliminary statistics, there are 9. 4 ×106ha of mire, 8. 0 × 106ha of lake, 2. 1 × 106ha of salt marsh, 2.1 × 107ha of shallow sea (0 - 5m), and 3. 8 × 107ha of paddyfield, their total area amounts to 8. 45× 107ha. Wetland consists of natural wetland system and man-made wetland system. According to hydrology, landform, soil and vegetation etc., natural wetland can be divided into the following types: marine, esturine, riverine, lacustrine, palustrine subsystems. On the basis of the wetland bottom compound, waterlogged state and vegetation forms, it can be subdivided into 26 wetland classes. Man-made wetland can be subdivided into 4 wetland classes. Wetland is a unique landscape in the earth and one of the most important living environment with rich resources and many functions. At present, 262 different types of Wetland Natural Reserves have been established in China, in which 7 Wetland Nature Reserves have been listed in international important wetlands of The Wetland
基金This work was supported by the National Key Research and Development Program of China (2017YFC0504301)the Strategic Priority Research Program of Chinese Academy of Sciences,Pan-Third Pole Environment Study for a Green Silk Road (Pan-TPE)
文摘We produced and analyzed oasis structure information, and evaluated oasis functional stability using the multiple indicators based on Remote Sensing(RS) and Geographical Information System(GIS) in the arid region of China in 2015. The results showed that the oases area was 193,734 km^2, accounting for 8.17% of the arid region of China. The spatial difference in the functional stability of oases was obvious. The Beijiang zone had the highest functional stability and was relatively stable state, and the Hexi Corridor-Alashan Plateau zone had the lowest functional stability and was relatively unstable. The functional stability is dominated by production and ecological functions, which have regional differences. Increasing oasis agricultural output, strengthening highway infrastructure construction and paying attention to education will become important ways to improve oasis functional stability. Water resources determine the ecological function, thus affecting the oasis functional stability. The results provide references for the formulation of related policies according to local conditions.
基金The Key Projects of the Guangdong Education Department under contract No.2019KZDXM019the Fund of Southern Marine Science and Engineering Guangdong Laboratory(Zhanjiang)under contract No.ZJW-2019-08+2 种基金High-Level Marine Discipline Team Project of Guangdong Ocean University under contract No.002026002009the Guangdong Graduate Academic Forum Project under contract No.230420003the"First Class"discipline construction platform project in 2019 of Guangdong Ocean University under contract No.231419026。
文摘This study presents an analysis of the spectral characteristics of remote sensing reflectance(Rrs)in northwestern South China Sea based on the in situ optical and water quality data for August 2018.Rrswas initially divided into four classes,classes A to D,using the max-classification algorithm,and the spectral properties of whole Rrs were characterized using the empirical orthogonal function(EOF)analysis.Subsequently,the dominant factors in each EOF mode were determined.The results indicated that more than 95%of the variances of Rrs are partly driven by the back-scattering characteristics of the suspended matter.The initial two EOF modes were well correlated with the total suspended matter and back-scattering coefficient.Furthermore,the first EOF modes of the four classes of Rrs(A-D Rrs-EOF1)significantly contributed to the total variances of each Rrs class.In addition,the correlation coefficients between the amplitude factors of class A-D Rrs-EOF1 and the variances of the relevant water quality and optical parameters were better than those of the unclassified ones.The spectral shape of class ARrs-EOF1 was governed by the absorption characteristic of chlorophyll a and colored dissolved organic matter(CDOM).The spectral shape of class B Rrs-EOF1 was governed by the absorption characteristic of CDOM since it exhibited a high correlation with the absorption coefficient of CDOM(ag(λ)),whereas the spectral shape of class C Rrs-EOF1 was governed by the back-scattering characteristics but not affected by the suspended matter.The spectral shape of class D Rrs-EOF1 exhibited a relatively good correlation with all the water quality parameters,which played a significant role in deciding its spectral shape.
基金supported by Sub Four Programme of Public Health Welfare Research Special Funds[grants No.201202010]Natural Science Fund Commission of China[H2609/81673232]the Yale Center for Interdisciplinary Research on Acquired Immune Deficiency Syndrome supported by National Institutes of Health grant[P30MH062294]
文摘We sought to identify the differences between adolescents left behind in their home villages/towns(LBA)and non-left behind adolescents(NLB)on subjective well-being and family functioning due to parental migration in south China.We used a stratified cluster sampling method to recruit middle school students in a city experiencing population-emigration in Jiangxi Province in 2010.Participants included adolescents from families with:(1)one migrant parent,(2)both parents who migrated,or(3)non-left behind adolescents(i.e.,no migrant parent).To determine predictors of subjective well-being,we used structural equation models.Adolescents left behind by both parents(LBB)were less likely to express life satisfaction(P=0.038)in terms of their environments(P=0.011)compared with NLB.A parent or parents who migrated predicts lower subjective well-being of adolescents(P=0.051)and also lower academic performance.Being apart from their parents may affect family functioning negatively from an adolescent's viewpoint.Given the hundreds of millions of persons in China,many who are parents,migrating for work,there may be mental health challenges in some of the adolescents left behind.
基金supported by the National Science Foundation of China(No.U1839210)。
文摘The North China Craton(NCC)is one of the oldest cratons on earth.Several important tectonic transformations of MesozoicCenozoic tectonic regime led to the destruction of the North China craton.The knowledge of crustal structure can provide important constraints for the formation and evolution of cratons.New maps of sediment thickness,crustal thickness(H)and v_(P)/v_(S)(κ)in the central and western NCC were obtained using sequential H-κstacking.P-wave receiver functions are calculated using teleseismic waveform data recorded by 405 stations from Chin Array project.Benefiting from the densely distribution of temporary seismic stations,our results reveal details of the crustal structure in the study area.The thickness of sedimentary layer in North China ranges from 0–6.4 km,and the thickest sedimentary layer is in Ordos block and its surroundings(about 2.8–6 km);The thickness of sedimentary layer in the Mongolia fold belt and Yinshan orogenic belt is relatively thin(less than 1 km).The crustal thickness of the study area varies between 27–48 km,of which the crust of the North China Plain is about 30–33 km,the central NCC is about 33–40 km,and the Ordos block is 40–48 km thick.The average v_(P)/v_(S)ratios in the study area is mostly between 1.66 and 1.90,and that in the Yanshan-Taihang mountain fold belt is between 1.70 and 1.85,and that in the Ordos block is between 1.65 and 1.90,with an average value of 1.77,indicating the absence of a thick basaltic lower crust.The obvious negative correlation between crustal thickness and average v_(P)/v_(S)ratio within Ordos and Central Asia orogenic belt may be related to magmatic underplating during the crustal formation.There is no significant correlation between the crustal thickness and the v_(P)/v_(S)ratio in the Lüliang-Taihang mountain fold belt,which may be related to the multiple geological processes such as underplating and crustal extension and thinning in this area.The lack of correlation between crust thickness and topography in the central orogenic belt and the North China Basin indicates the topography of these areas are controlled not only by crustal isostatic adjustment but also by the lithospheric mantle processes.
文摘Since the reform and opening up,China's market-oriented agricultural management reform has achieved remarkable results,but the reform has not yet been put in place,and there are some flaws in some areas of reform.To deepen the reform of government's agricultural management reform under the new situation,it is necessary to further define the boundary between government and market on the basis of following the general rules of world's agricultural development and considering China's special situation of agriculture,nail down the scope of government functions,pinpoint the key areas of reform,and actively promote the rapid development of China's characteristic modern agriculture.
基金Key Project of National Natural Science Foundation of China, No.41371409 National Key Technology R＆D Program, No.2013BAC03B00
文摘China had implemented the national strategies for Major Function-oriented Zones （MFOZs） to realize the goal of national sustainable development since 2010. This study analyzed and compared spatio-temporal characteristics and differences in built-up area for China＇s MFOZs using a China＇ s Land Use Database （CLUD） derived from high-resolution remotely sensed images in the periods of 2000-2010 and 2010-2013. To sum up： （1） The percentage of built-up area in each of the MFOZs was significantly different, revealing the gradient feature of national land development based on the distribution of the main functions. （2） Annual growth in built-up area in optimal development zones （ODZs） decreased signifi- cantly during 2010-2013 compared with the period 2000-2010, while annual growth in built-up area in key development zones （KDZs）, agricultural production zones （APZs） and key ecological function zones （KEFZs） increased significantly. （3） In ODZs, the average annual increase in built-up area in the Yangtze River Delta region was significantly higher than in other regions; the average area increase and rate of increase of built-up area in KDZs was faster in the western region than in other regions; average annual area growth of built-up area in APZs in the northeast, central and western regions was twice as high as the previous decade on average; the annual rate of change and increase in the dynamic degree of built-up area were most notable in KEFZs in the central region. （4） The spatial pattern and charac- teristics of built-up area expansions in the period 2010-2013 reflected the gradient feature of the plan for MFOZs. But the rate of increase locally in built-up area in ODZs, APZs and KEFZs is fast, so the effective measures must be adopted in the implementation of national and regional policies. The conclusions indicated these methods and results were meaningful for future regulation strategies in optimizing national land development in China.
