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GIS model for identifying urban areas vulnerable to noise pollution: case study 被引量:1
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作者 Stefan BILASCO Corina GOVOR +3 位作者 Sanda ROSCA Iuliu VESCAN Sorin FILIP loan FODOREAN 《Frontiers of Earth Science》 SCIE CAS CSCD 2017年第2期214-228,共15页
The unprecedented expansion of the national car ownership over the last few years has been determined by economic growth and the need for the population and economic agents to reduce travel time in progressively expan... The unprecedented expansion of the national car ownership over the last few years has been determined by economic growth and the need for the population and economic agents to reduce travel time in progressively expanding large urban centres. This has led to an increase in the level of road noise and a stronger impact on the quality of the environment. Noise pollution generated by means of transport represents one of the most important types of pollution with negative effects on a population's health in large urban areas. As a consequence, tolerable limits of sound intensity for the comfort of inhabitants have been determined worldwide and the generation of sound maps has been made compulsory in order to identify the vulnerable zones and to make recommendations how to decrease the negative impact on humans. In this context, the present study aims at presenting a GIS spatial analysis model-based methodology for identifying and mapping zones vulnerable to noise pollution. The developed GIS model is based on the analysis of all the components influencing sound propagation, represented as vector databases (points of sound intensity measurements, buildings, lands use, transport infrastructure), raster databases (DEM), and numerical databases (wind direction and speed, sound intensity). Secondly, the hourly changes (for representative hours) were analysed to identify the hotspots characterised by major traffic flows specific to rush hours. The validated results of the model are represented by GIS databases and useful maps for the local public administration to use as a source of information and in the process of making decisions. 展开更多
关键词 gis modelling noise pollution sound intensity environmental impact VULNERABILITY
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Environmental Analysis Using Integrated GIS and Spatial Configurations in Israel 被引量:1
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作者 Aybars Oztuna 《Journal of Geographic Information System》 2023年第2期267-293,共27页
The scope for environmental analysis constitutes a critical factor in recent times, yet demanding importance due to the concerns of environmental sustainability. The study aims at analysing the prospects of implementi... The scope for environmental analysis constitutes a critical factor in recent times, yet demanding importance due to the concerns of environmental sustainability. The study aims at analysing the prospects of implementing an integrated GIS and spatial configuration for environment analysis in Israel. The study adopts an empirical study design to consider the multi-dimensional utilisation of an integrated GIS and spatial configuration for environment analysis. The study considers the materials and methods of the GIS system modelling as well, consisting of satellite imagery, GPS-based location identification, Esri ArcGIS, CyberGIS, and BIM integration to present a comprehensive system for the environmental analysis of Israel. The results of the study indicate that the threats of natural disasters and climate change can be identified based on the synergy of spatial data within an integrated GIS modelling. In many cases, it is also used in collaboration with a BIM to ensure that planning and decision-making processes are sustainable, economically beneficial and environmentally considered. Thus, it is concluded that environmental analysis through the projection of visually represented satellite imagery within an integrated GIS with spatial configurations in Israel can minimise the conflicts between the infrastructural designs, human activities, and environmental sustainability. 展开更多
关键词 gis gis modelling Spatial Configuration Environment Analysis Israel Geospatial Intelligence System Spatial Data Analysis
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Hypergraph-based Object-oriented Model and Hypergraph Theory for GIS 被引量:2
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作者 ZHANGJin GONGJianya 《Geo-Spatial Information Science》 2002年第1期37-43,共7页
This paper discusses the features and relevant theories of GIS spatial data model based on hypergraph,etc.The integrated concept model based on hypergraph and object_oriented model (HOOM) is proposed by the authors.Th... This paper discusses the features and relevant theories of GIS spatial data model based on hypergraph,etc.The integrated concept model based on hypergraph and object_oriented model (HOOM) is proposed by the authors.The principal contribution of this paper is that we study the K_section and other theories of hypergraph.An application example using HOOM is given at the end of the paper. 展开更多
关键词 HYPERGRAPH object_oriented gis spatial data model HBDS DEM
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DEVELOPMENT OF A GIS DATA MODEL WITH SPATIAL,TEMPORAL AND ATTRIBUTE COMPONENTS BASED ON OBJECT-ORIENTED APPROACH 被引量:2
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作者 SHI Wenzhong ZHANG Minwen 《Geo-Spatial Information Science》 2000年第1期17-23,共7页
This paper presents a conceptual data model, the STA-model, for handling spatial, temporal and attribute aspects of objects in GIS. The model is developed on the basis of object-oriented modeling approach. This model ... This paper presents a conceptual data model, the STA-model, for handling spatial, temporal and attribute aspects of objects in GIS. The model is developed on the basis of object-oriented modeling approach. This model includes two major parts: (a) modeling the signal objects by STA-object elements, and (b) modeling relationships between STA-objects. As an example, the STA-model is applied for modeling land cover change data with spatial, temporal and attribute components. 展开更多
关键词 OBJECT-ORIENTATION gis data modeling spatial temporal and attribute model
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Fractal and Multifractal Modeling of Hydrothermal Mineral Deposit Spectrum: Application to Gold Deposits in Abitibi Area, Ontario, Canada 被引量:13
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作者 Cheng Qiuming Department of Earth and Atmospheric Science, Department of Geography, York University, Toronto, Canada M3J1P3 Faculty of Earth Resources, China University of Geosciences, Wuhan 430074 《Journal of China University of Geosciences》 SCIE CSCD 2003年第3期199-206,共8页
A number of fractal/multifractal methods are introduced for quantifying the mineral deposit spectrum which include a number-size model, grade-tonnage model, power spectrum model, multifractal model and an eigenvalue s... A number of fractal/multifractal methods are introduced for quantifying the mineral deposit spectrum which include a number-size model, grade-tonnage model, power spectrum model, multifractal model and an eigenvalue spectrum model. The first two models characterize mineral deposits spectra based on relationships among the measures of mineral deposits. These include the number of deposits, size of deposits, concentration and volume of mineral deposits. The last three methods that deal with the spatial-temporal spectra of mineral deposit studies are all expected to be popularized in near future. A case study of hydrothermal gold deposits from the Abitibi area, a world-class mineral district, is used to demonstrate the principle as well as the applications of methods proposed in this paper. It has been shown that fractal and multifractal models are generally applicable to modeling of mineral deposits and occurrences. Clusters of mineral deposits were identified by several methods including the power spectral analysis, singularity analysis and the eigenvalue analysis. These clusters contain most of the known mineral deposits in the Timmins and Kirkland Lake camps. 展开更多
关键词 mineralization spectrum POWER-SPECTRUM multifractal spectrum eigenvalue spectrum and gis modeling
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GIS-based assessment of land-agroforestry potentiality of Jharkhand State, India
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作者 Firoz AHMAD Nazimur Rahman TALUKDAR +3 位作者 Laxmi GOPARAJU Chandrashekhar BIRADAR Shiv Kumar DHYANI Javed RIZVI 《Regional Sustainability》 2022年第3期254-268,共15页
Scaling-up agroforestry area in various forms is a scientific path towards achieving various sustainable development goals(SDGs),especially improving livelihood,reducing poverty,conserving environment and biodiversity... Scaling-up agroforestry area in various forms is a scientific path towards achieving various sustainable development goals(SDGs),especially improving livelihood,reducing poverty,conserving environment and biodiversity,and transforming climate change.In this study,the effort was made to investigate the land potentiality for agroforestry at the district level in Jharkhand State,India by applying geographic information system(GIS)modeling technology using climate(temperature and precipitation),topography(slope and elevation),ecology(percent tree cover and normalized difference vegetation index(NDVI)),and social economics(poverty rate and tribal dominance)factors.The results revealed that six districts of Jharkhand State had agroforestry potential greater than 60.00%.The highest agroforestry suitability was found in Simdega District(78.20%),followed by Pakur(76.25%),West Singhbhum(72.70%),Dumka(68.84%),Sahibganj(64.63%),and Godda(63.43%)districts.Additionally,we identified 513 out of 32,620 villages of Jharkhand State potentially suitable(agroforestry suitability≥80.00%)for agroforestry with the objective of life improvement among marginalized society.Under the outside forest area,8.58%of the total geographical land of Jharkhand State was wasteland,much of which was found suitable for agroforestry practices.The agroforestry setups in those wastelands can absorb 637 t carbon annually in long run and can provide direct economic benefits to the locals besides additional income for carbon emission reduction.This study concluded that Jharkhand State has plenty of high potential land for agroforestry,and adoption of agroforestry at the village level must be given high priority.This study could guide the nodal authorities to prepare appropriate strategies for scaling the tree cover in agroforestry systems in village-level landscape planning which needs policy attention and investment for achieving 9 out of the 17 SDGs. 展开更多
关键词 Agroforestry suitability Land potential Climate change Topography Food security gis modeling Poverty alleviation Sustainable development goals (SDGs)
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Geospatial Analysis of Urban Heat Island Effects and Tree Equity
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作者 Jillian Gorrell Sharon R. Jean-Philippe +3 位作者 Paul D. Ries Jennifer K. Richards Neelam C. Poudyal Rochelle Butler 《Open Journal of Forestry》 2024年第1期1-18,共18页
In recent decades, Urban Heat Island Effects have become more pronounced and more widely examined. Despite great technological advances, our current societies still experience great spatial disparity in urban forest a... In recent decades, Urban Heat Island Effects have become more pronounced and more widely examined. Despite great technological advances, our current societies still experience great spatial disparity in urban forest access. Urban Heat Island Effects are measurable phenomenon that are being experienced by the world’s most urbanized areas, including increased summer high temperatures and lower evapotranspiration from having impervious surfaces instead of vegetation and trees. Tree canopy cover is our natural mitigation tool that absorbs sunlight for photosynthesis, protects humans from incoming radiation, and releases cooling moisture into the air. Unfortunately, urban areas typically have low levels of vegetation. Vulnerable urban communities are lower-income areas of inner cities with less access to heat protection like air conditioners. This study uses mean evapotranspiration levels to assess the variability of urban heat island effects across the state of Tennessee. Results show that increased developed land surface cover in Tennessee creates measurable changes in atmospheric evapotranspiration. As a result, the mean evapotranspiration levels in areas with less tree vegetation are significantly lower than the surrounding forested areas. Central areas of urban cities in Tennessee had lower mean evapotranspiration recordings than surrounding areas with less development. This work demonstrates the need for increased tree canopy coverage. 展开更多
关键词 Spatial Analysis Land Cover Urban Heat Island Effect (UHIE) EVAPOTRANSPIRATION Tree Canopy Impervious Surface gis Prediction model gis Machine Learning
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GIS Applications for Building 3D Campus, Utilities and Implementation Mapping Aspects for University Planning Purposes
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作者 Abdulla AI-Rawabdeh Nadhir A1-Ansari +1 位作者 Hussain Attya Sven Knutsson 《Journal of Civil Engineering and Architecture》 2014年第1期19-28,共10页
In city planning managing, the third dimension is becoming a necessity. Using 3D GIS modeling offers a flexible interactive system while providing one of the best visual interpretation of data which supports planning ... In city planning managing, the third dimension is becoming a necessity. Using 3D GIS modeling offers a flexible interactive system while providing one of the best visual interpretation of data which supports planning and decision processes for city planners. As a result, 3D GIS model expresses terrain features in an intuitive way which enhances the management and analysis of a proposed project through 3D visualization. This paper discusses the concept of 3D GIS modeling techniques using a simple procedure to generate a university campus model (real 3D GIS model) which will show the effectiveness of this approach. The 3D GIS model provides access to mapping data to support planning, design and data management. Intelligent GIS models and GIS tools help community planning and apply regional and discipline-specific standards. Integration of GIS spatial data with campus organization helps to improve quality, productivity and asset management. The following study built 3D GIS map and all utility information for AI al-Bayt University campus as an example. The primary objective is to improve data management (e.g., maps, plans, usage of facilities and services) and to develop methods using 3D spatial analysis for specific applications at the university. 展开更多
关键词 3D gis model ArcScene DATABASE AI al-Bayt University Jordan.
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An integrated method to calculate the spatial distribution of overburden strata failure in longwall mines by coupling GIS and FLAC^(3D) 被引量:14
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作者 Zhao Xiaodong Jiang Jian Lan Bochao 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2015年第3期369-373,共5页
The spatial distribution of overburden strata failure is of significant importance to affect the safety of underground mining. Because the traditional methods cannot be applied in all coal mines due to geological cond... The spatial distribution of overburden strata failure is of significant importance to affect the safety of underground mining. Because the traditional methods cannot be applied in all coal mines due to geological conditions or mining structures, a method of coupling FLAC3D with GIS was presented to calculate the spatial distribution of overburden strata failure in longwall coal mines. After building the spatio-temporal database from the calculation results of FLAC3D, the height of the mining-induced fractured zone in the overburden strata can be calculated by using the given height function. The results of case study show that the height of the fractured zone reached the maximum value at the face advance equal to about the panel width. The outcome of the work presented will be helpful in practice to improve safety in the production. 展开更多
关键词 gis Overburden strata Spatial modeling Coupling
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Quantitative evaluation of the risk induced by dominant geomorphological processes on different land uses, based on GIS spatial analysis models
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作者 Bilasco STEFAN Rosca SANDA +3 位作者 Fodorean IOAN Vescan IULIU Filip SORIN Petrea DANUT 《Frontiers of Earth Science》 SCIE CAS CSCD 2018年第2期311-324,共14页
Maramures Land is mostly characterized byagricultural and forestry land use due to its specificconfiguration of topography and its specific pedoclimaticconditions. Taking into consideration the trend of the lastcentur... Maramures Land is mostly characterized byagricultural and forestry land use due to its specificconfiguration of topography and its specific pedoclimaticconditions. Taking into consideration the trend of the lastcentury from the perspective of land management, adecrease in the surface of agricultural lands to theadvantage of built-up and grass lands, as well as anaccelerated decrease in the forest cover due to uncontrolledand irrational forest exploitation, has become obvious. Thefield analysis performed on the territory of Maramures Land has highlighted a high frequency of two geomor-phologic processes - landslides and soil erosion - whichhave a major negative impact on land use due to their rateof occurrence. The main aim of the present study is the GISmodeling of the two geomorphologic processes, determin-ing a state of vulnerability (the USLE model for soilerosion and a quantitative model based on the morpho-metric characteristics of the territory, derived from the HG.447/2003) and their integration in a complex model ofcumulated vulnerability identification. The modeling of therisk exposure was performed using a quantitative approachbased on models and equations of spatial analysis, whichwere developed with modeled raster data structures andprimary vector data, through a matrix highlighting thecorrespondence between vulnerability and land useclasses. The quantitative analysis of the risk was performedby taking into consideration the exposure classes asmodeled databases and the land price as a primaryalphanumeric database using spatial analysis techniquesfor each class by means of the attribute table. The spatialresults highlight the territories with a high risk to presentgeomorphologic processes that have a high degree ofoccurrence and represent a useful tool in the process ofspatial planning. 展开更多
关键词 risk evaluation spatial analysis gis modeling soil erosion LANDSLIDES spatial planning
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Using Multi Techniques Analysis in Biogeoclimatic Ecosystem Classification and Mapping of Mambilla Plateau in Taraba State Nigeria
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作者 Gabriel Salako Oluwasogo Olalubi +3 位作者 Henry Sawyerr Glenn Howe Abel Adebayo Abdulrasheed Adio 《Open Journal of Ecology》 2016年第7期412-426,共15页
This work used multi techniques analysis comprises GIS models, geostatistics, clustering analysis as against the traditional single layer thematic approach to characterize Mambilla Plateau, a cold highland in Taraba s... This work used multi techniques analysis comprises GIS models, geostatistics, clustering analysis as against the traditional single layer thematic approach to characterize Mambilla Plateau, a cold highland in Taraba state of Nigeriainto biogeoclimatic ecosystem zones needed for natural resources management. The principal criteria used in classifying and mapping the ecosystems are: climate and bioclimate data, physiography (slope, relief and aspect), vegetation/landcover data. In classifying and mapping the physiography of Mambilla Plateau, the topographic layer was produced from 90 m NASA/SRTM digital elevation model. Principal component analysis, agglomerative hierarchical cluster analysis (AHC) and geostatistical techniques (Kriging) were applied to develop bioclimatic layer. A combination of vegetation field survey conducted on selected sites, un/supervised classification and the application of NDVI values was used to produce landcover map and delineation of the Plateau into vegetation units. These layers of physiographic, bioclimatic and vegetation were spatially combined using fuzzy (sum) overlay in Arc GIS 10.2 to produce 5 major and 1 subunit biogeoclimatic ecosystem zones on the Mambilla Plateau and the adjoining landscape namely: humid lowland forest/humid shrubby forest, montane forest, escarpment stream valley forest, grass cypress cool mountain and, grass eucalyptus cold high mountain. It is expected that this approach to biogeoclimatic ecosystem mapping shall form the bedrock for vegetal/forest resources management not only in the region but find application especially in most of the highland of the world. 展开更多
关键词 Biogeoclimatic Ecosystem gis models Vegetal Resources Management Classification MAPPING
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A ubiquitous knowledgeable data representation model(UKRM) for three-dimensional geographic information systems(3D GIS) 被引量:2
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作者 ZHANG ShuQing ZHOU ChengHu +1 位作者 ZHANG JunYan CHEN XiangCong 《Science China Earth Sciences》 SCIE EI CAS CSCD 2016年第4期780-794,共15页
In the face of complicated, diversified three-dimensional world, the existing 3D GIS data models suffer from certain issues such as data incompatibility, insufficiency in data representation and representation types, ... In the face of complicated, diversified three-dimensional world, the existing 3D GIS data models suffer from certain issues such as data incompatibility, insufficiency in data representation and representation types, among others. It is often hard to meet the requirements of multiple application purposes(users) related to GIS spatial data management and data query and analysis, especially in the case of massive spatial objects. In this study, according to the habits of human thinking and recognition, discrete expressions(such as discrete curved surface(DCS), and discrete body(DB)) were integrated and two novel representation types(including function structure and mapping structure) were put forward. A flexible and extensible ubiquitous knowledgeable data representation model(UKRM) was then constructed, in which structurally heterogeneous multiple expressions(including boundary representation(B-rep), constructive solid geometry(CSG), functional/parameter representation, etc.) were normalized. GIS's ability in representing the massive, complicated and diversified 3D world was thus greatly enhanced. In addition, data reuse was realized, and the bridge linking static GIS to dynamic GIS was built up. Primary experimental results illustrated that UKRM was overwhelmingly superior to the current data models(e.g. IFC, City GML) in describing both regular and irregular spatial objects. 展开更多
关键词 Discrete curved surface(DCS) Discrete body(DB) Discrete structure Function structure Mapping structure "2D/3D" integrated representation 3D gis data model UKRM model
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Geographical Design of Riparian Buffers with Long-term Vegetation Cover Reconstructed in Agricultural Landscapes
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作者 LIU Wenbao GU Fengxia 《Journal of Northeast Agricultural University(English Edition)》 CAS 2009年第4期38-46,共9页
Reconstructing long-term vegetation cover along streams has become a popular practice for ecological restoration in fragmented agricultural landscapes. To maximize ecological restoration benefits with the least cost, ... Reconstructing long-term vegetation cover along streams has become a popular practice for ecological restoration in fragmented agricultural landscapes. To maximize ecological restoration benefits with the least cost, this paper developed a GIS- based model framework for the geographical design of the location and width of riparian buffers to be reconstructed with long-term vegetation cover. The framework integrated three models: the 0-1 mathematical programming model, an economical model and an ecological model. It was tested in an agricultural landscape with a drainage system consisting of 92 stream segments with cropland banks. Each segment had five restoration options in terms of buffer width: 0, 5, 10, 15 and 20 m, thus making a total of 460 decision units in the landscape. For each unit, the economical model estimated the annual rental payment to the farmer who owned the targeted cropland margin along a stream to be converted into a vegetation buffer, whereas the ecological model predicted its corresponding habitat benefits at the landscape level. The 0-1 programming model minimized the total payments, subject to the designed habitat improvement and proposed acreages of riparian cropland set-aside annually. The model identified a cost-effective combination of riparian buffers from 460 units. The results showed that achieving the habitat improvement goal at the least cost required a spatial configuration of vegetation buffers with variable width. This finding suggests that the size and location of buffers directly affect restoration costs and environmental benefits. Thus, the best management practices of agricultural landscape restoration can only be achieved by a specific geographical design with the model framework. 展开更多
关键词 spatial decision riparian habitat wildlife protection corridor gis cost-distance model
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Field strength prediction of mobile communication network based on GIS
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作者 CHEN Xiaoyong WU Hualing Tran Minh TRI 《Geo-Spatial Information Science》 SCIE EI 2012年第3期199-206,共8页
This article describes GIS-based models successfully developed for predicting the coverage of Cityphone cellular network,visualizing the predicted signal strength,and analyzing the field strength coverage.In order to ... This article describes GIS-based models successfully developed for predicting the coverage of Cityphone cellular network,visualizing the predicted signal strength,and analyzing the field strength coverage.In order to predict the signal coverage strength of communication network more accurately,the spatial and nonspatial databases of a mobile cellular network are combined by GIS and produce the necessary parameters.A GIS model named COST-231-Walfisch–Ikegami model(WIM)is developed for signal coverage prediction in Ho Chi Minh City.Radio-line-of-sight and nonradio-lineof-sight conditions can be determined by this model.In addition,in case of nonradio-line-of-sight conditions,average building height,building separation,building width,incident radio path,and road orientation with respect to the direct radio path were obtained using GIS.Road orientation loss,multiscreen diffraction loss,and shadowing gain were predicted more accurate by this model.The scale of maps in the experiment was 1:2000 and the average of floor height was 3 m because there were no exact building height measurements.Statistical results show that the path loss predicted by the COST 231 WIM overcame the real path loss of each cell station.And this method can be used for signal coverage prediction of mobile cellular network in urban areas.Compared to the current situation with the Ho Chi Minh City Posts and Telecommunications system,this model can be effectively applied to improve the Cityphone mobile network quality as well as capability.Developed GIS models can help designers in predicting cell station coverage using real spatial maps that make the results more reliable.This research can help network operators improve the network quality and capability with the best investment efficiently. 展开更多
关键词 mobile communication network gis model field strength prediction
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Surveys of rodent-borne disease in Thailand with a focus on scrub typhus assessment 被引量:1
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作者 Kriangkrai Lerdthusnee Joseph Nigro +8 位作者 Taweesak Monkanna Warisa Leepitakrat Surachai Leepitakrat Sucheera Insuan Weerayut Charoensongsermkit Nittaya Khlaimanee Wilasinee Akkagraisee Kwanta Chayapum James W.Jones 《Integrative Zoology》 SCIE CSCD 2008年第4期267-273,共7页
The epidemiology of many rodent-borne diseases in South-East Asia remains ill-defined.Scrub typhus and lep-tospirosis are common and medically significant,while other zoonotic diseases,such as spotted fever group Rick... The epidemiology of many rodent-borne diseases in South-East Asia remains ill-defined.Scrub typhus and lep-tospirosis are common and medically significant,while other zoonotic diseases,such as spotted fever group Rickettsiae have been identified,but their overall medical significance is unknown.Rodent surveillance was con-ducted from June 2002 to July 2004 in 18 provinces from Thailand.Traps were set up for one to three nights.Blood and serum samples and animal tissue samples(liver,spleen,kidney and urinary bladder)were collected.Chigger-mites,ticks and fleas were removed from captured rodents.Atotal of 4536 wild-caught rodents from 27 species were captured over two years of animal trapping.Rattus rattus was the dominant species,followed by Rattus exulans and Bandicota indica.Almost 43000 ectoparasites were removed from the captured animals.Approximately 98%of the ectoparasites were chigger-mites,of which 46%belonged to the genus Leptotrombidium(scrub typhus vector).Other genera included Schoengastia and Blankaartia.Tick and flea specimens together comprised less than 1%of the sample.Among the five species of ticks collected,Haemaphysalis bandicota was the predominant species caught,followed by Ixodes granulatus other Haemaphysalis spp.,Rhipicephalus spp.and Dermacentor spp.Only two species of fleas were collected and Xenopsylla cheopis(rat flea)was the predominant species.Using both commercial diagnostic kits and in-house molecular assays,animal tissue samples were examined and screened for zoonotic diseases.Seven zoonotic diseases were detected:scrub typhus,leptospirosis,murine typhus,tick typhus,bartonella,babesiosis and trypanosomiasis.Most samples were positive for scrub typhus.Other zoonotic diseases still under investigation include borrelosis,ehrlichiosis,the plague,and other rickettsial diseases.Using geo-graphic information systems,global positioning systems and remote sensing technology,epidemiological and environmental data were combined to assess the relative risk in different biotopes within highly endemic areas of scrub typhus in Thailand. 展开更多
关键词 gis model rodent-borne diseases scrub typhus surveillance surveys.
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Geomorphological monitoring of a highly dynamic estuary using oblique aerial photographs
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作者 I.Abou El-Magd P.F.Hillman 《International Journal of Digital Earth》 SCIE 2009年第2期109-121,共13页
Bad weather in many countries limits the use of optical satellite imageries in spatial and temporal monitoring of the environment.In this paper,a series of lowaltitude oblique aerial photos taken on daily,weekly and m... Bad weather in many countries limits the use of optical satellite imageries in spatial and temporal monitoring of the environment.In this paper,a series of lowaltitude oblique aerial photos taken on daily,weekly and monthly intervals were used to monitor the geomorphological changes in the upper part of the Mersey Estuary,northwestern England.This low-altitude aerial photo methodology reveals itself to be a satisfying compromise between cost,accuracy and difficulty of implementation.It offered a large amount of information on a spatial and temporal scale aiding in the understanding of channel mobility.This was an important consideration in the sitting and installation of new bridge pier foundations.This series of oblique aerial photos was used in a dynamic model to determine the migration of the ebb channel and was effective in identifying the main route of flow.Few uncertainties were encountered and the level of accuracy achieved in resolving these uncertainties in the images was in the range from 40 cm to a maximum of 1.7 m.This was compared with historical navigation charts and showed good correlation.Further applications are required to improve the quality of the data output from these images and the development of the technique. 展开更多
关键词 GEOMORPHOLOGY ESTUARY gis modelling oblique aerial photography UK
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Measuring the spatiotemporal variation and evolution of transport network of China's megaregions 被引量:11
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作者 SONG Ge YANG Jiawen 《Journal of Geographical Sciences》 SCIE CSCD 2016年第10期1497-1516,共20页
Megaregion has become a prominent feature of modern China. Reflecting upon China's recent path of transport infrastructure construction, this research examines the spatiotemporal characteristics of transport network ... Megaregion has become a prominent feature of modern China. Reflecting upon China's recent path of transport infrastructure construction, this research examines the spatiotemporal characteristics of transport network development and its accessibility impacts in China's ten megaregions from 1982 to 2010. Using historical transport network data and multiple national censuses (1982, 1990, 2000 and 2010), we computed two levels of indicators of megaregional transport network: megaregion level and county level, and analyzed the intra-megaregion and inter-megaregion disparities of transport network of the ten megaregions of China. Transport networks at the megaregion level are measured by three indicators: 1) transport network density; 2) infrastructure endowment per capita; and 3) size of transport network's standard ellipse. Two accessibility indicators for measuring transportation network at the county level are calculated: weighted average travel time and potential accessibility. The research results show the following: 1) Road and rail network densities witnessed the greatest growth during the 2000-2010 period, and growth was more significant for railway network. 2) By 2010, average road endowments per capita in inland megaregions became higher than in coastal megaregions, while average rail endowments per capita in coastal megaregions became higher than in inland megaregions. 3) The sizes and directions of the standard deviational ellipses of road and rail network changed continuously during the study period. However the changes of road network ellipses were relatively small, while the changes of railway network ellipses were more significant. 4) Megaregions have all benefited significantly from transportation infrastructure improvement in the past few decades in terms of WATT and potential accessibility, but the three giant megaregions benefited most. 展开更多
关键词 China megaregions transport network ACCESSIBILITY gis transport network model
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