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Geographical differentiation of riverine DOM composition and source apportionment:A case study of a riverine network of a mountainous stream,a Plain River,and an artificial canal
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作者 Jun-wei Zhao Shuang-bing Huang +2 位作者 Zhao-xin Su Wei-Chao Huang Yong Qian 《Journal of Groundwater Science and Engineering》 2026年第1期59-68,共10页
To elucidate the geographical differentiation characteristics and driving mechanisms of Dissolved Organic Matter(DOM)in typical rivers,this study conducted a multi-spectral investigation on three representative river ... To elucidate the geographical differentiation characteristics and driving mechanisms of Dissolved Organic Matter(DOM)in typical rivers,this study conducted a multi-spectral investigation on three representative river types within Shandong Province:The mountainous Dawen River,the plain Tuhai River,and the artificial East Grand Canal.The DOM composition was analyzed using Ultraviolet-Visible(UV-Vis)absorption spectroscopy,Excitation-Emission Matrix(EEM)fluorescence spectroscopy,and parallel factor analysis(PARAFAC),while Principal Component Analysis(PCA)was employed to quantify the synergistic effects of natural processes and anthropogenic activities.Results revealed significant spatial heterogeneity in DOM composition and sources.The plain river exhibited the highest aromaticity(humic-like components:43.3%)due to long-term agricultural non-point source inputs and urban wastewater discharge.The mountain stream,shaped by complex terrain and relatively intact ecosystems,was dominated by autochthonous DOM derived from microbial metabolism,with higher Fluorescence Index(FI=2.12)and biological index(BIX=1.35)than other river types.The artificial canal retained protein-like components(64.2%),largely attributed to winter hydrological stagnation and disturbances from shipping activities.Further analysis demonstrated that geographical settings(e.g.,mountain terrain)and anthropogenic activities(e.g.,agriculture,shipping)jointly regulated DOM composition by altering the balance between input and transformation processes.Integrated fluorescence parameters and PCA results suggested differentiated management strategies:protecting ecological integrity in mountain streams to sustain selfpurification,enhancing non-point source interception in plain rivers,and mitigating shipping pollution in canals.This study systematically reveals the natural-anthropogenic coupling mechanisms driving DOM dynamics in northern China rivers,providing critical insights for precision water environment management at the watershed scale. 展开更多
关键词 Dissolved organic matter(DOM) UV-Vis spectroscopy Parallel factor analysis(PARAFAC) geographical settings Anthropogenic activities
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Geographical Engineering and Its Role in Promoting Integrated Geography Research 被引量:2
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作者 LIU Yansui SU Sixin LI Xuhong 《Chinese Geographical Science》 2025年第1期1-23,共23页
Throughout the contemporary Chinese history of geography,geographical engineering has consistently played a pivotal role as a fundamental scientific activity.It possesses its distinct ontological basis and value orien... Throughout the contemporary Chinese history of geography,geographical engineering has consistently played a pivotal role as a fundamental scientific activity.It possesses its distinct ontological basis and value orientation,rendering it inseparable from being merely a derivative of geographical science or technology.This paper defines geographical engineering and introduces its development history through the lens of Chinese geographical engineering praxises.Furthermore,it is highlighted the logical and functional consistency between the theory of human-earth system and the praxis of geographical engineering.Six modern cases of geographical engineering projects are presented in detail to demonstrate the points and characteristics of different types of modern geographical engineering.Geographical engineering serves as an engine for promoting integrated geography research,and in response to the challenge posed by fragmented geographies,this paper advocates for an urgent revitalization of geographical engineering.The feasibility of revitalizing geographical engineering is guaranteed because it aligns with China’s national strategies. 展开更多
关键词 geographical engineering geographical science and engineering integrated geography research human-earth system Chinese geography
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Geographical patterns and drivers of plant productivity and species diversity in the Qinghai-Tibet Plateau 被引量:1
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作者 Yun-Long Pan Hai-Ping Tang +1 位作者 Dong Liu Yong-Gui Ma 《Plant Diversity》 2025年第6期908-919,共12页
The Qinghai-Tibet Plateau(QTP)has three main grassland types:alpine meadow,alpine steppe,and alpine desert steppe.In this study,we asked how plant productivity and species diversity vary with altitude,longitude and la... The Qinghai-Tibet Plateau(QTP)has three main grassland types:alpine meadow,alpine steppe,and alpine desert steppe.In this study,we asked how plant productivity and species diversity vary with altitude,longitude and latitude in alpine grasslands of the QTP.We then identified the environmental factors that drive these observed patterns of plant productivity and species diversity.We found that although plant productivity and species diversity varied greatly across large-scale longitudinal and latitudinal gradients,these changes were strongest across the longitudinal gradient.This finding indicates that moisture rather than temperature has the greatest impact on plant productivity and species diversity of the alpine grasslands in the QTP.We also found that besides soil and climate factors,partial pressure of carbon dioxide(pCO_(2))also has significant effects on plant productivity,and barometric pressure and partial pressure of oxygen(pO_(2))also have significant effects on species diversity.Furthermore,the relationship between the biomass of grassland-dominant species and species diversity was affected by the spatial scale at which these factors were studied.Our study provides new insights into the interconnections between plant productivity and species diversity and the major factors that influence alpine grasslands.It also provides a scientific basis for the maintenance of plant diversity and ecosystem functions in hypoxic(low-oxygen)regions. 展开更多
关键词 Alpine grassland Plant productivity Species diversity geographical distribution Qinghai-Tibet Plateau
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Geographical distribution and characterization of Jingmen tick virus in wild boars in China
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作者 Tong Wang Yu Guo +6 位作者 Yu Xu Heting Sun Peng Peng Siyuan Qin Guoqiang Zhu Changchun Tu Zhongzhong Tu 《Virologica Sinica》 2025年第1期137-140,共4页
Dear Editor,In recent decades,vector-transmitted emerging and re-emerging diseases pose public health issues around the world,in which emerging tick-borne viruses(TBVs)have played a major role since they are widely di... Dear Editor,In recent decades,vector-transmitted emerging and re-emerging diseases pose public health issues around the world,in which emerging tick-borne viruses(TBVs)have played a major role since they are widely distributed.TBVs have a wide range of hosts,including humans,livestock and rodents,with some of them able to cause severe diseases in human and domestic animals,such as Jingmen tick virus(JMTV)(Qin et al.,2014),tick-borne encephalitis virus(TBEV)(Xing et al.,2017),and Alongshan virus(ALSV)(Wang et al.,2019).Of the merging TBVs,JMTV is a novel pathogen that was first identified in Rhipicephalus microplus collected from the Jingmen city of Hubei province,China in 2010(Qin et al.,2014). 展开更多
关键词 Wild boars alongshan virus alsv wang Host range Jingmen tick virus China Public health issues Emerging tick borne viruses geographical distribution
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Geography and geographical knowledge contribute decisively to all sustainable development goals and targets
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作者 Paulo Pereira Wenwu Zhao 《Geography and Sustainability》 2025年第1期1-13,共13页
Geography is a discipline that touches multiple sciences and has been key to bridging numerous fields of knowl edge.This gives geography the advantage of connecting natural(e.g.,biology,ecology,climatology,geomorphol ... Geography is a discipline that touches multiple sciences and has been key to bridging numerous fields of knowl edge.This gives geography the advantage of connecting natural(e.g.,biology,ecology,climatology,geomorphol ogy)with social and human(e.g.,education,demography,sociology)sciences.The spatialisation of information from different sciences allows us to understand distribution patterns and connections between different realities.Thus,geographical knowledge is essential for an integrated and consistent understanding of our world.The Sus tainable Development Goals(SDGs)established by the United Nations(UN)in 2015 were essential to unifying the world towards a common goal.To achieve these,17 goals and 169 targets were created,and knowledge from multiple sciences is needed to support them.It is a huge challenge,and different knowledge branches are needed to connect.Geography and geographical knowledge have this capacity and support all 17 goals and 169 targets.Although this is a reality,as it will be explained in this editorial,SDG’s achievement for some is becoming utopic and unrealistic due to our world’s differences.It is time to think about the post-2030 SDGs,in which geography and geographic knowledge will be essential unequivocally. 展开更多
关键词 GEOGRAPHY geographical knowledge Sustainable Development Goals Post-2030 SDGs
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Geographical Indications and Regional Public Brands of the Whole Rice Industry Chain in the Yangtze River Economic Belt
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作者 Min ZHANG Li GAO +2 位作者 Dongjing LI Juncheng ZHU Bin HU 《Asian Agricultural Research》 2025年第1期1-13,共13页
The Yangtze River Economic Belt is the main rice producing area in China.The rice industry chain is the agricultural pillar industry chain of this economic belt and it is the key to ensuring national food security and... The Yangtze River Economic Belt is the main rice producing area in China.The rice industry chain is the agricultural pillar industry chain of this economic belt and it is the key to ensuring national food security and promoting comprehensive rural revitalization.This study discusses the entire rice industry chain in the Yangtze River Economic Belt from the national rice production functional zones,agricultural product quality and safety,national famous and excellent new agricultural products,national specialty agricultural products,"China's good grain and oil"products,and national advantageous characteristic industrial clusters.Then,it discusses the geographical indications of rice and its products in this economic belt from geographical indication products,geographical indication trademarks,agricultural geographical indications,geographical indication standards,geographical indication special indications,national geographical indication product protection demonstration zones,and Chinese geographical indication products protected by the European Union.In addition,it analyzes the five main problems between geographical indications and public brands,such as the limited use of geographical indication specific signs and the imperfect intellectual property protection system for geographical indications.Finally,it proposes eight strategies,including promoting the high-quality development of the entire rice industry chain,creating a geographical indication regional public brand for rice and its products,and implementing geographical indication protection projects. 展开更多
关键词 Yangtze River Economic Belt Rice and its products Entire industry chain geographical indication Regional public brand
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Geographical distance and stock price synchronization: evidence from China
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作者 Xiong Xiong Chenghao Ruan Yongqiang Meng 《Financial Innovation》 2025年第1期2792-2818,共27页
The effects of geographic factors on information dissemination among investors have been extensively studied;however,the relationship between the geographical distance and stock price synchronization remains unclear.G... The effects of geographic factors on information dissemination among investors have been extensively studied;however,the relationship between the geographical distance and stock price synchronization remains unclear.Grounded in information asymmetry theory,this study investigates the impact of geographical distance on stock price synchronization in the Chinese stock market.Using the data from the Shanghai and Shenzhen Stock Exchanges,we find that a greater geographical distance between mutual funds and firms considerably increases stock price synchronization,highlighting a strong positive relationship.Additional analysis show that firms in the regions with better external and internal governance,benefit more from reduced information asymmetry,than those in less regulated or transparent regions.These results have key implications for institutional investors and policymakers aiming to enhance information dissemination and market integration in China. 展开更多
关键词 geographical distance Stock price synchronization Institutional investor
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Cluster Analysis of Morphologic Characteristic of Eight Geographical Populations of Rana Dybowskii 被引量:1
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作者 应璐 徐艳春 +2 位作者 黄孝明 田秀华 汪青雄 《Agricultural Science & Technology》 CAS 2008年第1期104-106,110,共4页
[ObJective] The research aimed to determine the geographic distribution map of system of Rana dybowskii. [Method] Four morphologic indices (body length, body weight, forelimb length, hindlimb length) of eight geogra... [ObJective] The research aimed to determine the geographic distribution map of system of Rana dybowskii. [Method] Four morphologic indices (body length, body weight, forelimb length, hindlimb length) of eight geographical populations of R.dybowskii which naturally distribute in Changhai Mountain and Xiaoxing'an Mountain were measured. Measure results were variance analyzed and cluster analyzed. [Result] Variance analysis showed: the genetic branching among the Dongfanghong male population( belongs to Wandashan) and Xiaoxing'an Mountain male population and Changbai Mountain male population were significantly different (P〈0.05) ; the genetic branching between the Hebei female population (belongs to Xiaoxing'an Mountain) and Changbai Mountain female population was significantly different (P〈0.05 ). Cluster analysis showed : male R.dybowskii can be divided into three groups : the first group included Quanyang, Tianbei, Chaoyang and Ddkouqin, the second group included Tieli and Anshan, the third group included Dongfanghong; and the female R. dybowskii can be divided into three groups : the first group included Quanyang and Chaoyang, the second group included Tianbei and Dakouqin, the third group included Hebei. [Condusion] The paper deduced that the Sanjiang Plain was the geographical origin center ofR. dybowskii which radiated to Changbai Mountain and Xiaoxing'an Mountain along the adverse current of Songhua River basin, therefore, the current distribution pattern of R. dybowskii was formed. 展开更多
关键词 Rana dybowskii geographical population Morphologic characteristic Distribution pattern geographical origin Cluster analysis
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Research on Geographical Indications and Cultural Heritage of Famous Tea in Hubei 被引量:1
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作者 孙志国 黄莉敏 +2 位作者 熊晚珍 王树婷 钟学斌 《Agricultural Science & Technology》 CAS 2012年第3期502-506,536,共6页
In the study, analysis was made on present situation and development measures of geographical indications and cultural heritage protection of famous teas in Hubei Province. In addition, 8 related suggestions were prop... In the study, analysis was made on present situation and development measures of geographical indications and cultural heritage protection of famous teas in Hubei Province. In addition, 8 related suggestions were proposed as well. 展开更多
关键词 TEA geographical indication Cultural heritage Tangible cultural heritage Intangible cultural heritage Hubei Province
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Research on Geographical Environment and Culture Symbiosis of Chishui River Basin 被引量:1
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作者 王爱华 彭恩 《Journal of Landscape Research》 2011年第11期81-85,共5页
This paper took Chishui River Basin as the research object,and pointed out that its culture,which reflected local life and production and was featured with regional characteristics as well as abundant cultural connota... This paper took Chishui River Basin as the research object,and pointed out that its culture,which reflected local life and production and was featured with regional characteristics as well as abundant cultural connotation,was constituted by native natural and cultural geography,folk customs and historical feature.The relation between Chishui salt path and salt business culture under the typical closed and half-closed geographical environment was analyzed to indicate that the realignment of Chishui River had brought prosperity of Chishui River,booming of commercial towns,and development of ancient architectures and guild hall culture.The relation between rich natural resources and production and life culture of Chishui River was explained to show that Danxia landform nurtured stone culture,Chishui River resources cultivated fishing culture,special hydrogeological environment fostered liquor culture represented by Maotai,and Bamboo culture accumulated for hundreds of years.Finally,it introduced military culture and the spirit of the Long March forming based on the special location of Chishui River.It emphasized that geological environment was the important basis for human's survival and played an immeasurable role in the cultural development of a region. 展开更多
关键词 Chishui RIVER BASIN CULTURE geographical ENVIRONMENT SYMBIOSIS
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Retrospect and prospect of Geographical Sciences in China: A comparison with the Strategic Directions for Geography in the USA 被引量:4
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作者 SUN Jun PAN Yujun +1 位作者 TANG Maolin WU Youde 《Journal of Geographical Sciences》 SCIE CSCD 2013年第6期963-977,共15页
Understanding the Changing Planet: Strategic Directions for the Geographical Sciences (UCP), published by the National Research Council (USA), and its comments in The Professional Geographer propose that uppercas... Understanding the Changing Planet: Strategic Directions for the Geographical Sciences (UCP), published by the National Research Council (USA), and its comments in The Professional Geographer propose that uppercase and plural "Geographical Sciences" (GS) is the strategic direction for geography in the next decade for better understanding of our rapidly changing planet. According to these comments, UCP valued technologies and tools exces- sively ("task"), and did not pay much attention to methodology ("discipline"). Actually, both "task" and "discipline" are geographical wings, especially in the time of "big science". Enlightenment from UCP and its comments is the strategic direction that should be balanced between "task" and "discipline", GS should be a three-dimensional construct of a disciplinary system, methodology, and technologies and tools, and this system should be scientific hu- manism based on scientific spirit and directed by humanism. During the last 60 years, Chi- nese geographers devoted themselves to GS, including practice and theory. Obviously pro- gress and outlook are proposed as interdisciplinary GS, Earth Surface Sciences (ESS) and Geographical Construction (GC). The disciplinary system of GS is very complex, and is composed of such human knowledge domains as sciences, technologies, engineering, and philosophy. The main mission is to research the open, complex, and macro earth system (not only scientifically, but also humanistically), and one significant methodology is "comprehen- sive integration of qualitative and quantitative means" (CIQQM). At the same time, another changing direction in Chinese geography is Human-Economic Geography (HEG). 展开更多
关键词 strategic directions for geography geographical sciences earth surface sciences geographical con-struction human-economic geography China
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Exploration of the spatial pattern of urban residential land use with geographically weighted regression technique: a case study of Nanjing,China 被引量:1
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作者 胡明星 吴江 朱选 《Journal of Southeast University(English Edition)》 EI CAS 2015年第1期149-156,共8页
As the traditional methods and technical means cannot meet the quantitative research needs of the urban land use patterns, quantitative research methods for the urban land use pattern are established via the GIS (geo... As the traditional methods and technical means cannot meet the quantitative research needs of the urban land use patterns, quantitative research methods for the urban land use pattern are established via the GIS (geographic information system ) technique combined with the related theories and models. Taking the city of Nanjing as an example, a spatial database of urban land use and other environmental and socio-economic data is constructed. A multiple linear regression model is developed to determine the statistically significant factors affecting the residential land use distributions. To explain the spatial variations of urban land use patterns, the geographically weighted regression (GWR) is employed to establish spatial associations between these significant factors and the distribution of urban residential land use. The results demonstrate that the GWR can provide an effective approach to the exploration of the urban land use spatial patterns and also provide useful spatial information for planning residential development and other types of urban land use. 展开更多
关键词 urban residential land use GIS (geographic information system) multiple linear regression geographically weighted regression
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Geographical Factor as a Basis for Research of State BordersmAn Example of Georgia
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作者 Dali A. Nikolaishvili Revaz Sh. Tolordava 《Journal of Earth Science and Engineering》 2013年第10期701-713,共13页
The work deals with analysis of geographical factor as one of the main factor determining the historical change of a border on the example of Georgia. The research was conducted in two main directions: the evaluation... The work deals with analysis of geographical factor as one of the main factor determining the historical change of a border on the example of Georgia. The research was conducted in two main directions: the evaluation of historical transformations of state borders of Georgia throughout of XIX-XX centuries and identification the leading geographical factors. Special emphasis has been made on geographical and cartometric analysis of modern state border of Georgia. In order to identify the historical transformations of state border that have used different methods as well as GIS-technologies, the research is based on the historical, cartographical and statistical data. On the base of a lot of cartographic sources, it is concluded that the borderline in modem topographic maps is often plotted by ignoring the international practice related to plotting the state borders across the physical-geographical objects. This is why the geographical factor seems important in the historical transformations of the state border creating similarly a negative perspective in the future. The main results of research are: (1) classification of geographical factors causing the transformations of the state borders; (2) Evaluation of sensitivity of state border; and (3) creation of DB of the state border of Georgia, allowing continuing the studies in the future. 展开更多
关键词 State Border types of Sate border cartometric-geographical analysis geographical factor Georgia.
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Geographical Patterns and Temporal Variations of Regional Dry and Wet Heatwave Events in China during 1960–2008 被引量:33
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作者 丁婷 钱维宏 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2011年第2期322-337,共16页
Daily maximum/minimum temperatures and relative humidity records from 510 stations in China for the period 1960–2008 were used to investigate geographical patterns and temporal variations of heatwave (HW) events. D... Daily maximum/minimum temperatures and relative humidity records from 510 stations in China for the period 1960–2008 were used to investigate geographical patterns and temporal variations of heatwave (HW) events. Dry and wet HW events were compared by different definitions. Regionally, both dry and wet HW events are commonly located in southeastern China in the monsoon area, with neither type occurring in the northeast part of Northeast China and Southwest China, while the north-northwest region of the country experiences dry HW events and a few wet HW events. In the southeast of the country, site dry HW events occurred from April to September and mostly in June, while site wet HW events occurred from April to October and mostly in September. In total, 163 regional wet HW events were identified. The ten longest regional wet HW events lasted for more than 20 days, while the mean duration for 163 events was about 11 days. For the top ten events, six occurred after the 1990s, compared with four before this time. Global surface warming was clear since 1979, but the frequency and severity of regional wet HW events were relatively low in the 1980s, increasing remarkably since the 1990s. Possible reasons for this might be the strong interdecadal and interannual variations in regional atmospheric circulations, as well as water transport related directly to temperature contrasts in different regions, rather than global-mean temperature changes. 展开更多
关键词 climate extreme HEATWAVE geographical pattern temporal variation China
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Profiling the ionome of rice and its use in discriminating geographical origins at the regional scale, China 被引量:18
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作者 Gang Li Luis Nunes +4 位作者 Yijie Wang Paul N. Williams Maozhong Zheng Qiufang Zhang Yongguan Zhu 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2013年第1期144-154,共11页
Element profile was investigated for their use to trace the geographical origin of rice (Oryza sativa L.) samples. The concentrations of 13 elements (calcium (Ca), potassium (K), magnesium (Mg), phosphorus (... Element profile was investigated for their use to trace the geographical origin of rice (Oryza sativa L.) samples. The concentrations of 13 elements (calcium (Ca), potassium (K), magnesium (Mg), phosphorus (P), boron (B), manganese (Mn), iron (Fe), nickel (Ni), copper (Cu), arsenic (As), selenium (Se), molybdenum (Mo), and cadmium (Cd)) were determined in the rice samples by inductively coupled plasma optical emission and mass spectrometry. Most of the essential elements for human health in rice were within normal ranges except for Mo and Se. Mo concentrations were twice as high as those in rice from Vietnam and Spain. Meanwhile, Se concentrations were three times lower in the whole province compared to the Chinese average level of 0.088 mg/kg. About 12% of the rice samples failed the Chinese national food safety standard of 0.2 mg/kg for Cd. Combined with the multi-elemental profile in rice, the principal component analysis (PCA), discriminant function analysis (DFA) and Fibonacci index analysis (FIA) were applied to discriminate geographical origins of the samples. Results indicated that the FIA method could achieve a more effective geographical origin classification compared with PCA and DFA, due to its efficiency in making the grouping even when the elemental variability was so high that PCA and DFA showed little discriminatory power. Furthermore, some elements were identified as the most powerful indicators of geographical origin: Ca, Ni, Fe and Cd. This suggests that the newly established methodology of FIA based on the ionome profile can be applied to determine the geographical origin of rice. 展开更多
关键词 ionome rice grain geographical origin principal component analysis Fibonacci index analysis
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Integrating TM and Ancillary Geographical Data with Classification Trees for Land Cover Classification of Marsh Area 被引量:14
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作者 NA Xiaodong ZHANG Shuqing +3 位作者 ZHANG Huaiqing LI Xiaofeng YU Huan LIU Chunyue 《Chinese Geographical Science》 SCIE CSCD 2009年第2期177-185,共9页
The main objective of this research is to determine the capacity of land cover classification combining spec- tral and textural features of Landsat TM imagery with ancillary geographical data in wetlands of the Sanjia... The main objective of this research is to determine the capacity of land cover classification combining spec- tral and textural features of Landsat TM imagery with ancillary geographical data in wetlands of the Sanjiang Plain, Heilongjiang Province, China. Semi-variograms and Z-test value were calculated to assess the separability of grey-level co-occurrence texture measures to maximize the difference between land cover types. The degree of spatial autocorrelation showed that window sizes of 3×3 pixels and 11×11 pixels were most appropriate for Landsat TM im- age texture calculations. The texture analysis showed that co-occurrence entropy, dissimilarity, and variance texture measures, derived from the Landsat TM spectrum bands and vegetation indices provided the most significant statistical differentiation between land cover types. Subsequently, a Classification and Regression Tree (CART) algorithm was applied to three different combinations of predictors: 1) TM imagery alone (TM-only); 2) TM imagery plus image texture (TM+TXT model); and 3) all predictors including TM imagery, image texture and additional ancillary GIS in- formation (TM+TXT+GIS model). Compared with traditional Maximum Likelihood Classification (MLC) supervised classification, three classification trees predictive models reduced the overall error rate significantly. Image texture measures and ancillary geographical variables depressed the speckle noise effectively and reduced classification error rate of marsh obviously. For classification trees model making use of all available predictors, omission error rate was 12.90% and commission error rate was 10.99% for marsh. The developed method is portable, relatively easy to im- plement and should be applicable in other settings and over larger extents. 展开更多
关键词 land cover classification classification trees Landsat TM ancillary geographical data MARSH
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Geographical Information System-Based Assessment of Ecological Security in Changbai Mountain Region 被引量:8
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作者 LU Xing-chang ZHANG Ji-quan LI Xiao-zhen 《Journal of Mountain Science》 SCIE CSCD 2014年第1期86-97,共12页
Ecological security defined as the creation of a condition where the physical surroundings of a community provide for the needs of its inhabitants without diminishing its natural stock,which is important for regional ... Ecological security defined as the creation of a condition where the physical surroundings of a community provide for the needs of its inhabitants without diminishing its natural stock,which is important for regional security and social stability.In recent years,land use patterns in the Changbai Mountain region have changed significantly with intensive human activities,and consequently led to increasing problems in regional ecological security.Based on the Pressure-State-Impact-Response(PSIR) model and the mathematical method of catastrophe progression supported by geographical information system(GIS),the ecological security situation of the study area under land use and cover change(LUCC) was evaluated.The results indicated that the ecological security in Changbai Mountain region varied nonlinearly,which got better from 1990 to 2000 but became worse from 2000 to 2007,the ecological security levels in Changbai Mountain region were mainly medium and medium to low during the past 17 years,with higher values of Ecological Security Index(ESI) in the central region and lower values in the east and west,the ecological security situation was more serious in the settlements and river valleys,where the LUCC was most remarkable. 展开更多
关键词 ECOLOGICAL security Pressure-State-Impact-Response Land use and COVER change geographical Information System(GIS) CATASTROPHE PROGRESSION Changbai MOUNTAIN
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A geographical and operational deep graph convolutional approach for flight delay prediction 被引量:11
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作者 Kaiquan CAI Yue LI +3 位作者 Yongwen ZHU Quan FANG Yang YANG Wenbo DU 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2023年第3期357-367,共11页
Flight delay prediction has attracted great interest in civil aviation community due to its significant role in airline planning,flight scheduling,airport operation,and passenger service.Flight delay is affected by nu... Flight delay prediction has attracted great interest in civil aviation community due to its significant role in airline planning,flight scheduling,airport operation,and passenger service.Flight delay is affected by numerous factors and irregularly propagates in air transportation networks owing to flight connectivity,which brings critical challenges to accurate flight delay prediction.In recent years,Graph Convolutional Networks(GCNs)have become popular in flight delay prediction due to the advantage in extracting complicated relationships.However,most of the existing GCN-based methods have failed to effectively capture the spatial-temporal information in flight delay prediction.In this paper,a Geographical and Operational Graph Convolutional Network(GOGCN)is proposed for multi-airport flight delay prediction.The GOGCN is a GCN-based spatial-temporal model that improves node feature representation ability with geographical and operational spatial-temporal interactions in a graph.Specifically,an operational aggregator is designed to extract global operational information based on the graph structure,while a geographical aggregator is developed to capture the similar nature among spatially close airports.Extensive experiments on a real-world dataset demonstrate that the proposed approach outperforms the state-of-the-art methods with a satisfying accuracy improvement. 展开更多
关键词 Flight delay prediction Flight operation pattern geographical interactive information Graph neural network Spatial-temporal information
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Quantification of driving factors on NDVI in oasis-desert ecotone using geographical detector method 被引量:7
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作者 ZHANG Yu ZHANG Ke-cun +1 位作者 AN Zhi-shan YU Yan-ping 《Journal of Mountain Science》 SCIE CSCD 2019年第11期2615-2624,共10页
Within oasis-desert ecotone regions,the normalized difference vegetation index(NDVI)is an important parameter for evaluating the growth of vegetation.An accurate quantitative study between NDVI and environmental and a... Within oasis-desert ecotone regions,the normalized difference vegetation index(NDVI)is an important parameter for evaluating the growth of vegetation.An accurate quantitative study between NDVI and environmental and anthropogenic factors is critical for understand the driving factors of vegetation growth in oasis-desert ecotone.In 2016,four periods Landsat 8 OLI_TIRS images,relevant climatological parameters data(air temperature,air relative humidity,wind velocity and accumulated temperature),land cover type data and soil data were selected as proxies.In order to quantify the explanatory power for NDVI spatial and temporal distribution in the southern edge of Dunhuang City and northern side of the Mingsha Mountain,the geographical detector model was used to explain the potential influences of factors versus the spatial distribution of NDVI,and each explanatory variable's relative importance can be calculated.The factor detector results disclose that the spatial distribution of NDVI is primarily dominated by land cover type.The risk detector results show that,high NDVI region is located within woodland.The mean value of NDVI displays an increase and then decrease trend with air temperature increase.With the increase of wind velocity and decrease of air relative humidity,the NDVI value shows a decrease trend.The interactive q values between the two factors are higher than any q value of separated factors.Results also indicate that the strongest interactive effects of NDVI are different in distinct seasons.Consequently,anthropogenic activity is more important than environmental factors on NDVI in oasis-desert ecotone.We also demonstrate that air relative humidity rather than air temperature have played a greater role in NDVI spatial distribution. 展开更多
关键词 Influence factors Normalized DIFFERENCE VEGETATION index geographical DETECTOR Oasis-desert ECOTONE
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