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Geoinformatics and digital earth initiatives:a German perspective 被引量:5
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作者 M.Ehlers 《International Journal of Digital Earth》 SCIE 2008年第1期17-30,I0002,共15页
This paper discusses the role of Geoinformatics as a new scientific discipline designed for handling of geospatial information.Depending on the scientific background of the people involved in shaping the emerging disc... This paper discusses the role of Geoinformatics as a new scientific discipline designed for handling of geospatial information.Depending on the scientific background of the people involved in shaping the emerging discipline,emphasis may be placed on different aspects of Geoinformatics.Applications and developments may address geoscientific,spatial planning,or computer science related matters.The scientific field of Geoinformatics encompasses the acquisition and storing of geospatial data,the modelling and presentation of spatial information,geoscientific analyses and spatial planning,and the development of algorithms and geospatial database systems.It is the position of the author that these tools from Geoinformatics are necessary to bridge the gap between Digital Earth models and the real world with its real-world problems(‘connecting through location’).It is,however,crucial that Geoinformatics represents a coherent integrated approach to the acquisition,storage,analysis,modeling,presentation,and dissemination of geo-processes and not a patchwork solution of unconnected fields of activity.Geoinformatics is as such not a part of Geography,Surveying,or Computer Science,but a new self-contained scientific discipline.The current paper highlights international and national trends of the discipline and presents a number of Geoinformatics initiatives.The research and teaching activities of the newly formed Institute for Geoinformatics and Remote Sensing(IGF)at the University of Osnabrueck serve as an example for these initiatives.All these developments have lead to the long overdue formation of a scientific‘Society for Geoinformatics’(German:Gesellschaft fu¨r Geoinformatik-GfGI)in Germany. 展开更多
关键词 GEOINFORMATICS digital earth modeling position paper emerging scientific discipline academic programmes
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Optimizing zero-shot text-based segmentation of remote sensing imagery using SAM and Grounding DINO
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作者 Mohanad Diab Polychronis Kolokoussis Maria Antonia Brovelli 《Artificial Intelligence in Geosciences》 2025年第1期14-24,共11页
The use of AI technologies in remote sensing(RS)tasks has been the focus of many individuals in both the professional and academic domains.Having more accessible interfaces and tools that allow people of little or no ... The use of AI technologies in remote sensing(RS)tasks has been the focus of many individuals in both the professional and academic domains.Having more accessible interfaces and tools that allow people of little or no experience to intuitively interact with RS data of multiple formats is a potential provided by this integration.However,the use of AI and AI agents to help automate RS-related tasks is still in its infancy stage,with some frameworks and interfaces built on top of well-known vision language models(VLM)such as GPT-4,segment anything model(SAM),and grounding DINO.These tools do promise and draw guidelines on the potentials and limitations of existing solutions concerning the use of said models.In this work,the state of the art AI foundation models(FM)are reviewed and used in a multi-modal manner to ingest RS imagery input and perform zero-shot object detection using natural language.The natural language input is then used to define the classes or labels the model should look for,then,both inputs are fed to the pipeline.The pipeline presented in this work makes up for the shortcomings of the general knowledge FMs by stacking pre-processing and post-processing applications on top of the FMs;these applications include tiling to produce uniform patches of the original image for faster detection,outlier rejection of redundant bounding boxes using statistical and machine learning methods.The pipeline was tested with UAV,aerial and satellite images taken over multiple areas.The accuracy for the semantic segmentation showed improvement from the original 64%to approximately 80%-99%by utilizing the pipeline and techniques proposed in this work.GitHub Repository:MohanadDiab/LangRS. 展开更多
关键词 Foundation models Multi-modal models Vision language models Semantic segmentation Segment anything model Earth observation Remote sensing
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Land use/land cover changes after the decline of mountain chalet farming in the Krkono?e and Hruby Jeseník Mountains, Czechia, since the mid-20th century
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作者 HEJDA Tomás KUPKOVA Lucie BOUDNY Zdeněk 《Journal of Mountain Science》 2025年第4期1119-1150,共32页
Chalet farming,as a specific type of agricultural landscape management,has been established in many European mountain ranges,including the Krkono?e Mountains and the Hruby Jeseník Mountains in Czechia.During the ... Chalet farming,as a specific type of agricultural landscape management,has been established in many European mountain ranges,including the Krkono?e Mountains and the Hruby Jeseník Mountains in Czechia.During the operation of such farming from 16/17th century till 1945,many changes in land use/land cover and landscape at all occurred,which are generally evaluated positively.Turbulent events including political,economic and social changes and the displacement of the German-speaking population associated with them in the mid-20th century rapidly ended this development,causing significant landscape changes,such as the abandonment of agricultural land and succession,afforestation,expansion of the alpine tree line,reduction of diversity.The aim of our study is to evaluate changes of land cover(forests,dwarf pine,grasslands,other areas)from 1936/1946 till 2021,secondary succession and driving forces of change for selected meadow enclaves in the Krkonose Mountains and the Hruby Jeseník Mountains after the decline of mountain chalet farming since the middle of 20th century.We used remote sensing methods(aerial imagery)and field research(dendrochronology and comparative photography)to detect the land use/land cover changes in the selected study areas in the Krkono?e Mountains and the Hruby Jeseník Mountains.We documented the process of the succession,which occurred almost immediately after the end of farming,peaking about 10–20 years later,with an earlier start in the Hruby Jeseník Mountains.The succession led to the significant change of land use/land cover and these processes were similar in both mountain ranges.The largest changes were a decrease in grasslands by 62%–64%and an increase in forest area by 33%–40%for both study areas.The abandonment of land is the main consequence of a crucial political driving forces(displacement of German-speaking population)in the Krkono?e Mountains and the Hruby Jeseník Mountains. 展开更多
关键词 Chalet farming Land use/land cover change Alpine treeline SUCCESSION Krkonoše Mountains HrubýJeseník Mountains
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Hybrid Deep Learning and Optimized Feature Selection for Oil Spill Detection in Satellite Images
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作者 Ghada Atteia Mohammed Dabboor +1 位作者 Konstantinos Karantzalos Maali Alabdulhafith 《Computers, Materials & Continua》 2025年第7期1747-1767,共21页
This study explores the integration of Synthetic Aperture Radar(SAR)imagery with deep learning and metaheuristic feature optimization techniques for enhanced oil spill detection.This study proposes a novel hybrid appr... This study explores the integration of Synthetic Aperture Radar(SAR)imagery with deep learning and metaheuristic feature optimization techniques for enhanced oil spill detection.This study proposes a novel hybrid approach for oil spill detection.The introduced approach integrates deep transfer learning with the metaheuristic Binary Harris Hawk optimization(BHHO)and Principal Component Analysis(PCA)for improved feature extraction and selection from input SAR imagery.Feature transfer learning of the MobileNet convolutional neural network was employed to extract deep features from the SAR images.The BHHO and PCA algorithms were implemented to identify subsets of optimal features from the entire feature dataset extracted by MobileNet.A supplemented hybrid feature set was constructed from the PCA and BHHO-generated features.It was used as input for oil spill detection using the logistic regression supervised machine learning classification algorithm.Several feature set combinations were implemented to test the classification performance of the logistic regression classifier in comparison to that of the proposed hybrid feature set.Results indicate that the highest oil spill detection accuracy of 99.2%has been achieved using the logistic regression classification algorithm,with integrated feature input from subsets identified using the PCA and the BHHO feature selection techniques.The proposed method yielded a statistically significant improvement in the classification performance of the used machine learning model.The significance of our study lies in its unique integration of deep learning with optimized feature selection,unlike other published studies,to enhance oil spill detection accuracy. 展开更多
关键词 Oil spill machine learning deep learning CLASSIFICATION metaheuristic optimization
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Habitat suitability modeling of a nearly extinct rosewood species (Dalbergia odorifera) under current, and future climate conditions
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作者 Jiuxin Lai Minliang Fan +5 位作者 Yu Liu Ping Huang Hannes Gaisberger Changhong Li Yongqi Zheng Furong Lin 《Journal of Forestry Research》 2025年第4期85-96,共12页
The influence of global climate change on endangered species is of growing concern, especially for rosewood species that are in urgent need of protection and restoration. Ecological niche models are commonly used to e... The influence of global climate change on endangered species is of growing concern, especially for rosewood species that are in urgent need of protection and restoration. Ecological niche models are commonly used to evaluate probable species’ distribution under climate change and contribute to decision-making to define efficient management strategies. A model was developed to forecast which habitat was most likely appropriate for the Dalbergia odorifera. We screened the main climatic variables that describe the current geographic distribution of the species based on maximum entropy modelling (Maxent). We subsequently assessed its potential future distribution under moderate (RCP2.6) and severe (RCP8.5) climate change scenarios for the years 2050 and 2070. The precipitation ranges of the wettest month and the warmest quarter are the primary limiting factors for the current distribution of D. odorifera among the climatic predictors. Climate change will be expected to have beneficial effects on the distribution range of D. odorifera. In conclusion, the main limits for the distribution of D. odorifera are determined by the level of precipitation and human activities. The results of this study indicate that the coasts of southern China and Chongqing will play a key role in the protection and restoration of D. odorifera in the future. 展开更多
关键词 Climate change Dalbergia odorifera Habitat suitability Model tunning Forest conservation
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Assessing Hyrcanian forest fire vulnerability:socioeconomic and environmental perspectives
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作者 Elnaz Nejatiyanpour Omid Ghorbanzadeh +5 位作者 Josef Strobl Rasoul Yousefpour Mahmoud Daneshvar Kakhki Hamid Amirnejad Khalil Gholamnia Mahmoud Sabouhi Sabouni 《Journal of Forestry Research》 2025年第3期189-207,共19页
The increasing frequency and intensity of forest fires,driven by climate change and human activities,pose a significant threat to vital forest ecosystems,particularly where fire is not a natural element in the regener... The increasing frequency and intensity of forest fires,driven by climate change and human activities,pose a significant threat to vital forest ecosystems,particularly where fire is not a natural element in the regeneration cycle.This study aims to identify the indicators influencing forest fire vulnerability and compare maps of forest fire susceptibility that are based on the Intergovernmental Panel on Climate Change tripartite model,with a focus on the vulnerable Hyrcanian forest region in Golestan Province,northern Iran,where forest fires have caused considerable economic losses.On the basis of expert opinions and a literature review,we used geographic information systems,remote sensing and machine learning techniques to select and weigh 30 biophysical,environmental and socioeconomic indicators that affect forest fire vulnerability in the study area.These indicators were rigorously normalized,weighted and amalgamated into a comprehensive forest fire vulnerability index to analyze forest exposure,sensitivity and adaptive capacity.We thus identified and mapped areas with very high forest fire exposure,high sensitivity and low adaptive capacity for urgent targeted intervention and strategic planning to mitigate the impacts of forest fires.The results also revealed a set of critical indicators that contribute more significantly to forest fire vulnerability(e.g.,precipitation,elevation and factors related to biodiversity,human activity and economic reliance on forest resources).Our results provide insights that can inform policy-making,community engagement and environmental management strategies to mitigate the vulnerabilities associated with forest fires in the Hyrcanian forest. 展开更多
关键词 Hyrcanian forest GIS Fire vulnerability Risk assessment POLICY-MAKING Disaster mitigation
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Improving service accessibility and equity for sustainable development goals without newly facilities by rural settlement reconstruction
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作者 Caihui Cui Zhigang Han +3 位作者 Feng Liu Jingru Ma Haiying Wang Xiang Chen 《Geography and Sustainability》 2025年第1期105-117,共13页
Ensuring the provision of accessible,affordable,and high-quality public services to all individuals aligns with one of the paramount aims of the United Nations’Sustainable Development Goals(SDGs).In the face of esca ... Ensuring the provision of accessible,affordable,and high-quality public services to all individuals aligns with one of the paramount aims of the United Nations’Sustainable Development Goals(SDGs).In the face of esca lating urbanization and a dwindling rural populace in China,reconstructing rural settlements to enhance public service accessibility has become a fundamental strategy for achieving the SDGs in rural areas.However,few stud ies have examined the optimal methods for rural settlement reconstruction that ensure accessible and equitable public services while considering multiple existing facilities and service provisions.This paper focuses on rural settlement reconstruction in the context of the SDGs,employing an inverted MCLP-CC(maximal coverage loca tion problem for complementary coverage)model to identify optimal rural settlements and a rank-based method for their relocation.Conducted in Changyuan,a county-level city in Henan Province,China,this study observed significant enhancements in both accessibility and equity following rural settlement reconstruction by utilizing the MH3SFCA(modified Huff 3-step floating catchment area)and the spatial Lorenz curve method.Remarkably,these improvements were achieved without the addition of new facilities,with the accessibility increasing by 44.21%,4.97%,and 3.11%;Gini coefficients decreasing by 19.53%,1.64%,and 3.18%;Ricci-Schutz coef-ficients decreasing by 21.09%,2.09%,and 4.33%for educational,medical,and cultural and sports facilities,respectively.It indicated that rural settlement reconstruction can bolster the accessibility and equity of public ser-vices by leveraging existing facilities.This paper provides a new framework for stakeholders to better reconstruct rural settlements and promote sustainable development in rural areas in China. 展开更多
关键词 SDGs EQUITY ACCESSIBILITY Rural settlement reconstruction Spatial optimization
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中国东北地区时间序列雪盖监测数据集
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作者 陈圣波 杨倩 +2 位作者 XIE Hongjie 周超 路鹏 《地理学报》 EI CSCD 北大核心 2014年第S01期I0077-I0082,178-184,共13页
东北地区是中国三大稳定积雪区,区域尺度的雪盖时空变化监测对水资源的有效利用和雪灾监测和预警具有重要意义。本数据集在2004-2013年美国地球观测卫星TERRA/AQUA-MODIS数据基础上经算法改进,自定义生产MODIS Terra/Aqua双星逐日融合数... 东北地区是中国三大稳定积雪区,区域尺度的雪盖时空变化监测对水资源的有效利用和雪灾监测和预警具有重要意义。本数据集在2004-2013年美国地球观测卫星TERRA/AQUA-MODIS数据基础上经算法改进,自定义生产MODIS Terra/Aqua双星逐日融合数据(MODISDC)和滑动多日融合数据(MODISMC)两种基础数据,并且反演积雪天数(Snow Cover Day,SCD)、积雪初日(Snow Onset Date,SCOD)和融雪终日(Snow Melting Date,SCMD)三类专题数据。利用气象站台实测逐日积雪深度数据,考虑云覆盖的影响,对MODIS双星逐日合成产品和滑动多日合成进行检验,总体精度分别为47.51%和76.52%,明显高于MODIS原始数据MOD10A1(34.45%)和MYD10A1(30.57%)。 展开更多
关键词 中国东北 雪盖数据 积雪天数 积雪初日 积雪终日
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利用GRACE重力卫星求解南极洲冰川质量变化的精度研究 被引量:2
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作者 Lorant FOLDVARY Annamaria KISS +2 位作者 苏子校 王广才 王林 《地学前缘》 EI CAS CSCD 北大核心 2015年第4期239-246,共8页
GRACE重力卫星可用于观测南极洲冰川的质量变化。由GRACE重力卫星提供的月解重力场能有效探测质量的年变化及长期变化(周期和非周期性)。通过GRACE观测的质量变化时间序列,计算得到南极洲质量的长期变化及周期性年变化。计算结果受多种... GRACE重力卫星可用于观测南极洲冰川的质量变化。由GRACE重力卫星提供的月解重力场能有效探测质量的年变化及长期变化(周期和非周期性)。通过GRACE观测的质量变化时间序列,计算得到南极洲质量的长期变化及周期性年变化。计算结果受多种误差影响,其中GRACE模型误差的影响较小,而研究时段及其跨度的影响较为显著,以不同宽度的时间窗口进行平移,得到无穷时间序列下该误差的参考值为±14.89mm/a。南极地区的气压修正误差可达±10mm/a,GIA修正误差与其量级相同。由此我们认为,目前对于南极洲冰川质量变化的一些认识仍需商榷。南极洲西部地区冰川加速消融,Dronning Maud Land和Enderby Land等地区的质量持续累积;其他地区的质量变化情况仍需进一步研究。 展开更多
关键词 南极洲 地表质量变化 误差分析 质量变化时间序列
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A novel vehicle navigation map matching algorithm based on fuzzy logic and its application 被引量:10
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作者 童小华 吴颂春 +1 位作者 吴淑琴 刘大杰 《Journal of Central South University of Technology》 SCIE EI CAS 2005年第2期214-219,共6页
A new real-time map matching algorithm based on fuzzy logic is proposed. 3 main factors affecting the reliability of map matching, including the distance between the vehicle location and the matching road segment, the... A new real-time map matching algorithm based on fuzzy logic is proposed. 3 main factors affecting the reliability of map matching, including the distance between the vehicle location and the matching road segment, the angle between the vehicle direction and the road segment direction and the road connectivity are discussed. Fuzzy rules for the distance, angle and connectivity are presented to calculate the matching reliability. 2 indicators for estimating the matching reliability are then derived, one is the lower limit of the reliability, and the other is the limit error of the difference between the maximal value and the second-maximal value of the reliability. A real-time map-matching system based on fuzzy logic is therefore developed. Using the real data of global positioning system(GIS) based navigation and geographic information system(GPS) based road map, the method is verified and the (results) prove the effectiveness of the proposed method. 展开更多
关键词 map matching fuzzy logic RELIABILITY GPS GIS road network
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Current global trends in the incidence of pediatric-onset inflammatory bowel disease 被引量:43
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作者 Josef Sykora Renta Pomahacov +3 位作者 Marcela Kreslová Dominika Cvalínová Premysl Stych Jan Schwarz 《World Journal of Gastroenterology》 SCIE CAS 2018年第25期2741-2763,共23页
AIM To perform a comprehensive review and provide an up-to-date synopsis of the incidence and trends of inflammatory bowel disease(IBD). METHODS We systematically searched the MEDLINE(source Pub Med), EMBASE and Cochr... AIM To perform a comprehensive review and provide an up-to-date synopsis of the incidence and trends of inflammatory bowel disease(IBD). METHODS We systematically searched the MEDLINE(source Pub Med), EMBASE and Cochrane Library databases in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines(period: 1985-2018) to identify studies reporting population-based data on the incidence of pediatriconset(< 19 years at diagnosis) IBD in full manuscripts. Two authors carried out screening and data extraction. Choropleth interactive maps and temporal trends were used to illustrate the international differences and incidences of and changes in IBD and subtypes.RESULTS In total, one hundred forty studies reporting data from 38 countries were considered in this review. The highest annual pediatric incidences of IBD were 23/100000 person-years in Europe, 15.2/100000 in North America, and 11.4/100000 in Asia/the Middle East and Oceania. The highest annual incidences of Crohn's disease(CD) were 13.9/100000 in North America and 12.3/100000 in Europe. The highest annual incidences of ulcerative colitis(UC) were 15.0/100000 in Europe and 10.6/100000 in North America. The highest annual incidences of IBD-unclassified(IBD-U) were 3.6/100000 in Europe and 2.1/100000 in North America. In the time-trend analyses, 67% of CD, 46% of UC and 11% of IBD-U studies reported an increasing incidence(P < 0.05). The risk of IBD is increasing among firstgeneration of migrant populations.CONCLUSION Globally, the incidence of IBD varies greatly by geographical areas. The steadily increasing incidence of pediatric IBD over time indicates its emergence as a global disease, suggesting that studies should investigate the environmental risk factors among pediatric cohorts. 展开更多
关键词 CHILDREN INCIDENCE Inflammatory bowel disease Crohn's disease Ulcerative colitis Inflammatory bowel disease-unclassified
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A zenith tropospheric delay correction model based on the regional CORS network 被引量:11
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作者 Huang Liangke Liu Lilong Yao Chaolong 《Geodesy and Geodynamics》 2012年第4期53-62,共10页
Tropospheric delay is a primary error source in earth observations and a variety of radio navigation technologies. In this paper, the relationship between zenith tropospheric delays and the elevation and longitude of ... Tropospheric delay is a primary error source in earth observations and a variety of radio navigation technologies. In this paper, the relationship between zenith tropospheric delays and the elevation and longitude of stations is analyzed using the zenith tropospheric delay final products of International GNSS Service (IGS) stations from 2011. Two new models are proposed for estimating zenith tropospheric delays from regional CORS data without meteorological data. The proposed models are compared with the direct interpolation method and the remove-restore method using data from Guangxi CORS. The results show that the new models significantly improve the calculated precision. Finally, the root mean square (RMS) errors of the new models were used to estimate the surface precipitable water vapor (PWV) value at CORS station, which was determined to be less than 2 mm. 展开更多
关键词 regional CORS zenith tropospheric delay regional modeling new model precision analysis
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Low-altitude geophysical magnetic prospecting based on multirotor UAV as a promising replacement for traditional ground survey 被引量:9
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作者 Alexander V.Parshin Vladimir A.Morozov +2 位作者 Anton V.Blinov Alexey N.Kosterev Alexander E.Budyak 《Geo-Spatial Information Science》 SCIE CSCD 2018年第1期67-74,共8页
The prospects for expanding the mineral resource base in many countries are linked with the exploration of stranded sites localized at unexplored areas with complex natural and landscape conditions that make any groun... The prospects for expanding the mineral resource base in many countries are linked with the exploration of stranded sites localized at unexplored areas with complex natural and landscape conditions that make any ground survey,including magnetic prospecting,difficult and expensive.The current level of geology requires high-precision and large-scale data at the first stages of geological exploration.Since 2012,technologies of aeromagnetic surveying with unmanned aircraft vehicles(UAV)enter the market,but most of them are based on big fixed-wing UAV and do not allow to substantially increase the level of survey granularity compared with traditional aerial methods.To increase the scale of survey,it is necessary to reduce the altitude and speed of flight,for which the authors develop the methodical and technical solutions described in this article.To obtain data at altitudes of 5 m above the terrain even in a rugged relief,we created heavy multirotor UAVs that are stable in flight and may be used in a wide range of environmental conditions(even a moderate snowfall),and develop a special software to generate flight missions on the basis of digital elevation models.A UAV has special design to reduce magnetic interference of the flight platform;the magnetic sensor is hung below the aircraft.This technology was conducted in a considerable amount of magnetic surveys in the mountainous regions of East Siberia between 2014 and 2016.The results of the comparison between airborne and ground surveys are presented,which show that the sensitivity of the developed system in conjunction with low-altitude measurements can cover any geologically significant anomalies of the magnetic field.An unmanned survey is cheaper and more productive;the multirotor-based technologies may largely replace traditional ground magnetic exploration in scales of 1:10,000−1:1000. 展开更多
关键词 Unmanned aircraft vehicles(UAV) magnetic survey geophysical prospecting airborne geophysics unmanned aerial system(UAS)
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The Occurrence of Oleananes in the Beibuwan Basin and Its Application to the Study of Maturity and Oil-Source Rock Correlation 被引量:10
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作者 LI Meijun WANG Tieguan +4 位作者 LIU Ju ZHANG Meizhu LU Hong MA Qinglin GAO Lihui 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2008年第3期585-595,共11页
The oleanane parameter, i.e., OP (oleananes/(oleananes+C30hopanes)) in the two sedimentary columns of the Beibuwan Basin, South China Sea, can be used to delimit the top of oil generation window, with Ro (/%) o... The oleanane parameter, i.e., OP (oleananes/(oleananes+C30hopanes)) in the two sedimentary columns of the Beibuwan Basin, South China Sea, can be used to delimit the top of oil generation window, with Ro (/%) of 0.53 in Well M1 and 0.55 in Wells H1/Hd1/Hd2, respectively. Comparing with vitrinite reflectance (Ro/%), the OP features a dynamic range and can indicate the oil generation window more precisely. By using OP and other geochemical indices, the oil-source correlation is also conducted. It suggests that the oils in wells M1 and M2 are derived from the source rocks in situ. The mudstone in Huachang uplift is not the main source rocks for oils in this area, The OP is also a useful oil-source correlation parameter in some Tertiary lacustrine basins. 展开更多
关键词 oleanane parameter (OP) BIOMARKER MATURITY oil-source correlation Fushan Depression
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New spatial dimensions of global cityscapes: From reviewing existing concepts to a conceptual spatial approach 被引量:4
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作者 GEORG Isabel BLASCHKE Thomas TAUBENB?CK Hannes 《Journal of Geographical Sciences》 SCIE CSCD 2016年第3期355-380,共26页
Current global urbanisation processes are leading to new forms of massive urban constellations. The conceptualisations and classifications of these, however, are often ambiguous, overlap or lag behind in scientific li... Current global urbanisation processes are leading to new forms of massive urban constellations. The conceptualisations and classifications of these, however, are often ambiguous, overlap or lag behind in scientific literature. This article examines whether there is a common denominator to define and delimitate–and ultimately map–these new dimensions of cityscapes. In an extensive literature review we analysed and juxtaposed some of the most common concepts such as megacity, megaregion or megalopolis. We observed that many concepts are abstract or unspecific, and for those concepts for which physical parameters exist, the parameters are neither properly defined nor used in standardised ways. While understandably concepts originate from various disciplines, the authors identify a need for more precise definition and use of parameters. We conclude that often, spatial patterns of large urban areas resemble each other considerably but the definitions vary so widely that these differences may surpass any inconsistencies in the spatial delimitation process. In other words, today we have tools such as earth observation data and Geographic Information Systems to parameterise if clear definitions are provided. This appears not to be the case. The limiting factor when delineating large urban areas seems to be a commonly agreed ontology. 展开更多
关键词 urban concepts large urban areas CONCEPTUALIZATION urbanization MEGACITY METROPOLIS ribbon development urban sprawl conurbation city region agglomeration megaregion urban corridor
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环境地球物理学:新概念(英文) 被引量:4
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作者 GueliS.Vakhromeev 《地学前缘》 EI CAS CSCD 2001年第1期47-57,共11页
环境地球物理学是勘探地球物理学新科学和新应用分支。环境地球物理定义为用仪器对以各种物理场形式出现的物质和能量进行测量进而对环境进行多重目的监控。环境地球物理再细分为灾害、防护及医学环境地球物理。对环境物理异常及其天然... 环境地球物理学是勘探地球物理学新科学和新应用分支。环境地球物理定义为用仪器对以各种物理场形式出现的物质和能量进行测量进而对环境进行多重目的监控。环境地球物理再细分为灾害、防护及医学环境地球物理。对环境物理异常及其天然和人工源进行了整理、分类。文中说明了地质生态目标和过程的静态和动态物理地质模型系统 ,以及多元建模原则。环境地球物理场的变化可作为地质环境演变部分或全部丧失其稳定性乃至被破坏的明显标志 ,且意义重大。灾害事件 (地震、滑坡、海震等 )的预报被证明是可能的。这些灾祸是各种技术因素或触发地质过程的结果 ,它们发展潜隐而发生突然 ,正如缓发生态地质炸弹一样。 展开更多
关键词 环境地球物理学 灾害地球物理 防护地球物理 医学地球物理 地质生态目标
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Precise Three-Dimensional Deformation Retrieval in Large and Complex Deformation Areas via Integration of Offset-Based Unwrapping and Improved Multiple-Aperture SAR Interferometry:Application to the 2016 Kumamoto Earthquake 被引量:5
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作者 Won-Kyung Baek Hyung-Sup Jung 《Engineering》 SCIE EI 2020年第8期927-935,共9页
Conventional synthetic aperture radar(SAR)interferometry(InSAR)has been successfully used to precisely measure surface deformation in the line-of-sight(LOS)direction,while multiple-aperture SAR interferometry(MAI)has ... Conventional synthetic aperture radar(SAR)interferometry(InSAR)has been successfully used to precisely measure surface deformation in the line-of-sight(LOS)direction,while multiple-aperture SAR interferometry(MAI)has provided precise surface deformation in the along-track(AT)direction.Integration of the InSAR and MAI methods enables precise measurement of the two-dimensional(2D)deformation from an interferometric pair;recently,the integration of ascending and descending pairs has allowed the observation of precise three-dimensional(3D)deformation.Precise 3D deformation measurement has been applied to better understand geological events such as earthquakes and volcanic eruptions.The surface deformation related to the 2016 Kumamoto earthquake was large and complex near the fault line;hence,precise 3D deformation retrieval had not yet been attempted.The objectives of this study were to①perform a feasibility test of precise 3D deformation retrieval in large and complex deformation areas through the integration of offset-based unwrapped and improved multiple-aperture SAR interferograms and②observe the 3D deformation field related to the 2016 Kumamoto earthquake,even near the fault lines.Two ascending pairs and one descending the Advanced Land Observing Satellite-2(ALOS-2)Phased Array-type L-band Synthetic Aperture Radar-2(PALSAR-2)pair were used for the 3D deformation retrieval.Eleven in situ Global Positioning System(GPS)measurements were used to validate the 3D deformation measurement accuracy.The achieved accuracy was approximately 2.96,3.75,and 2.86 cm in the east,north,and up directions,respectively.The results show the feasibility of precise 3D deformation measured through the integration of the improved methods,even in a case of large and complex deformation. 展开更多
关键词 Synthetic aperture radar(SAR) Conventional SAR interferometry(InSAR) Multiple-aperture SAR interferometry(MAI) ALOS-2 PALSAR-2 3D deformation retrieval 2016 Kumamoto earthquake
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Retrieval of sea surface winds under hurricane conditions from GNSS-R observations 被引量:5
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作者 JING Cheng YANG Xiaofeng +4 位作者 MA Wentao YU Yang DONG Di LI Ziwei XU Cong 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2016年第9期91-97,共7页
Reflected signals from global navigation satellite systems(GNSSs) have been widely acknowledged as an important remote sensing tool for retrieving sea surface wind speeds.The power of GNSS reflectometry(GNSS-R)sig... Reflected signals from global navigation satellite systems(GNSSs) have been widely acknowledged as an important remote sensing tool for retrieving sea surface wind speeds.The power of GNSS reflectometry(GNSS-R)signals can be mapped in delay chips and Doppler frequency space to generate delay Doppler power maps(DDMs),whose characteristics are related to sea surface roughness and can be used to retrieve wind speeds.However,the bistatic radar cross section(BRCS),which is strongly related to the sea surface roughness,is extensively used in radar.Therefore,a bistatic radar cross section(BRCS) map with a modified BRCS equation in a GNSS-R application is introduced.On the BRCS map,three observables are proposed to represent the sea surface roughness to establish a relationship with the sea surface wind speed.Airborne Hurricane Dennis(2005) GNSS-R data are then used.More than 16 000 BRCS maps are generated to establish GMFs of the three observables.Finally,the proposed model and classic one-dimensional delay waveform(DW) matching methods are compared,and the proposed model demonstrates a better performance for the high wind speed retrievals. 展开更多
关键词 global navigation satellite system-reflectometry Hurricane Dennis delay doppler maps bistatic radar cross section map sea surface wind speed
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Estimation of Some Chemical Properties of an Agricultural Soil by Spectroradiometric Measurements 被引量:3
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作者 T.JARMER M.VOHLAND +1 位作者 H.LILIENTHAL E.SCHNUG 《Pedosphere》 SCIE CAS CSCD 2008年第2期163-170,共8页
The contents of nitrogen and organic carbon in an agricultural soil were analyzed using reflectance measurements (n = 52) performed with an ASD FieldSpee-Ⅱ spectroradiometer. For parameter prediction, empirical mod... The contents of nitrogen and organic carbon in an agricultural soil were analyzed using reflectance measurements (n = 52) performed with an ASD FieldSpee-Ⅱ spectroradiometer. For parameter prediction, empirical models based on partial least squares (PLS) regression were defined from the measured reflectance spectra (0.4 to 2.4 μm). Here, reliable estimates were obtained for nitrogen content, but prediction accuracy was only moderate for organic carbon. For nitrogen, the real spatial pattern of within-field variability was reproduced with high accuracy. The results indicate the potential of this method as a quick screening tool for the spatial assessment of nitrogen and organic carbon, and therefore an appropriate alternative to time- and cost-intensive chemical analysis in the laboratory. 展开更多
关键词 agricultural soil NITROGEN organic carbon partial least squares regression spectroradiometric measurements
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Unmanned aerial vehicles(UAV)for assessment of qualitative classification of Norway spruce in temperate forest stands 被引量:11
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作者 Olga Brovkina Emil Cienciala +1 位作者 Peter Surový Přemysl Janata 《Geo-Spatial Information Science》 SCIE CSCD 2018年第1期12-20,共9页
The study investigates the potential of UAV-based remote sensing technique for monitoring of Norway spruce health condition in the affected forest areas.The objectives are:(1)to test the applicability of UAV visible a... The study investigates the potential of UAV-based remote sensing technique for monitoring of Norway spruce health condition in the affected forest areas.The objectives are:(1)to test the applicability of UAV visible an near-infrared(VNIR)and geometrical data based on Z values of point dense cloud(PDC)raster to separate forest species and dead trees in the study area;(2)to explore the relationship between UAV VNIR data and individual spruce health indicators from field sampling;and(3)to explore the possibility of the qualitative classification of spruce health indicators.Analysis based on NDVI and PDC raster was successfully applied for separation of spruce and silver fir,and for identification of dead tree category.Separation between common beech and fir was distinguished by the object-oriented image analysis.NDVI was able to identify the presence of key indicators of spruce health,such as mechanical damage on stems and stem resin exudation linked to honey fungus infestation,while stem damage by peeling was identified at the significance margin.The results contributed to improving separation of coniferous(spruce and fir)tree species based on VNIR and PDC raster UAV data,and newly demonstrated the potential of NDVI for qualitative classification of spruce trees.The proposed methodology can be applicable for monitoring of spruce health condition in the local forest sites. 展开更多
关键词 Remote sensing species classification spruce health indicator Unmanned Aerial System(UAS)
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