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  • 2010 Volume 12 Issue 6
    Published: 25 December 2010
      
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  • ARTICLES
    Design and Development of the Carbon Accounting and Decision Support System of LULUCF in China
    ZHAO Zhiping, SHAO Quanqin, WANG Junbang, LU Heli, CHEN Zhuoqi
    2010, 12(6): 743-752.
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    Along with society development,more and more greenhouse gases,such as carbon dioxide,methane,and nitrous oxide,were released to atmosphere by humanity.Scientific researches showed that the fact of global warming was incontrovertible,and how to contain or slow down global warming became a global hot spot of scientific research.In order to meet demands on evaluation of carbon source/sink inventories,UNFCCC invited the Intergovernmental Panel on Climate Change to develop Good Practice Guidance for Land Use,Land-Use Change and Forestry.Based on the.NET and ArcGIS technology,the Carbon Accounting and Decision Support System of LULUCF in China was developed to meet the requirements of National Negotiation under the climatic convention and management of carbon cycle in terrestrial ecosystem.The system was developed completely based on the IPCC idea and method,and it could efficiently integrated existed observation records,data,models and methods for dynamic assessments of Chinese terrestrial ecosystem carbon balance,carbon sink effects of LULUCF and implementation policies.In this article,we first introduced the design and framework of the system.Then we made a detailed description of the system functions and the managements of database.Followed,we described the process of system development and the operating procedures showed in the interface of the system with C# as the development language.Finally we summarized the innovative characteristics of the system.The Carbon Accounting and Decision System of LULUCF in China has complete functions and strong expandability,and it could accept many types of schemes for comparison.Considering the actual national condition,the system adopted native scientific achievements as possible in method,data and parameter to reduce the uncertainty of carbon list checking and ratifying.It would supply reliable and efficient method for secondary national green house gas list compilation,and scientific basis for National Negotiation under the climatic convention and the implementation of the convention.
  • ARTICLES
    Spatial Variation of Soil Moisture Content in Mining Subsidence Areas of DaLiuta,Shenmu County,Shannxi Province
    ZHAO Hongmei, ZHANG Fawang, SONG Yaxin, JING Enchun, WEI Wen, HAN Zhantao
    2010, 12(6): 753-760.
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    It is significant for environment protection and land reclamation to find out the influence of mining subsidence to soil moisture content by study the distribution and spatial variation of soil moisture content.This paper takes Shuanggou mining subsidence of Daliuta in Shenmu County,Shannxi Province as the test area to analysis the spatial variation of soil moisture content characteristic of coal mining subsidence by methods of traditional statistics and geostatistics.We set 69 sampling sites at the test area and collect 7 soil moisture content values at each site by TDR(Time Domain Reflectometry).Then we use the drying method to revise the original data obtained by TDR.The analytic results indicated that: soil physical characteristics of granularity,bulk density and porosity of mining soil changed due to converting and recomposing of soil layer vertically.So that,soil moisture content of mining subsidence more significantly reduced than that of natural soil by 14.2 % to 21.9% at the depth of 0 to 60cm.And the vertical variability of soil moisture content of subsidence was also stronger than that of natural soil with the coefficient of variation tended to be19.2% to 50% higher at all depths in the subsidence area than that of the native area.The Kriging contour maps of soil moisture content in the depth of 0,20,40 and 60cm of the test area showed that low value of soil moisture content lies in the collapse crater of subsidence area.It proved that soil moisture retention capability has been influenced remarkably by those subsidence configurations such as ground fissures,collapse pit or collapse cave in the ground surface.Soil moisture content reduction and enhancing in spatial variation directly resulted in the deterioration of vegetation living conditions.Furthermore,the ground landscape was also badly destroyed.
  • ARTICLES
    Study on the Comprehensive Appraisal Index System for Energy Security Risk:A Case of Coal and Oil
    ZHAO Jian'an, LI Hongqiang, LANG Yihuan, ZHENG Jingyun
    2010, 12(6): 761-766.
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    Studies on the comprehensive index system are foundational works and important contents for energy security risk appraising.Coal and oil are the principal part of energy supply and consumption in China.The security risk sources of coal and oil come from five aspects,i.e.resources,production,transportation,market and consumption.In fact,the comprehensive appraisal for security risk of coal and oil is the integration and synthesis of possibility assessments based on the risk sources mentioned above.After that,the comprehensive risk index of coal and oil is obtained.Based on hierarchical analysis model and comprehensive appraisal methods used in relative researches,an index system with 4 layers(i.e.target layer,guideline layer,sub-criteria layer and the index layer) and 14 indexes is established,the comprehensive risk degrees are determined,and a risk degree assessment model for the risk sources is built.By calculation of the assessment model,the coal and oil security comprehensive risk index(ESCRI) is brought about.Furthermore,an integrated grade of security risk for coal and oil is divided,which,including 5 levels of risk possibilities,i.e.very low,low,medium,high and very high.The results of this study are helpful for assessment and management of security risk for coal and oil,or even for all kinds of energy.And this paper suggests an example both theoretically and methodically for identification,prediction and responds to risks.
  • ARTICLES
    Analysis and Comparison in Arithmetic for Kriging Interpolation and Sequential Gaussian Conditional Simulation
    ZHAO Yanfeng, SUN Zhiying, CHEN Jie
    2010, 12(6): 767-776.
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    In this paper,the relation in arithmetic between Kriging interpolation and sequential Gaussian conditional simulation(SGCS)were inferred and the statistical parameters for Kriging interpolation,for SGCS and for the original data were compared.It demonstrated that a stochastic realization of SGCS calculated by Monte Carlo Method could be divided into two parts by mathematic transform,one was Kriging value,and the other was a stochastic deviation which followed a normal distribution with the mean = 0 and the variance equal to Kriging error variance.The comparison among Kriging interpolation,SGCS and the origin data showed that the variance of Kriging interpolation value was lower than that of the original data with a reduction equal to one Kriging error variance.This was a result of demanding for optimal weights in estimating,which was attributed to the smoothing effect during Kriging interpolation.And because of the smoothing effect,the variogram for Kriging interpolation was lower than that of the original data,though it kept no change in autocovariance.By adding the missing variance back into the SGCS,the smoothing effect was corrected,and it kept no change in variance,variogram and covariance.But the error variance caused by SGCS was as 2 times as Kriging error variance which showed that the precision of local estimate of a single SGCS was lower than that of Kriging.However,SGCS could correct the shortage by adequate repeats because the mean SGCS and Kriging interpolation share a same expectation in theory.And then,in the function of geography mapping mean SGCS was comparable with Kriging.In practice it could be concluded that the advantage of Kriging method was to provide accurate estimate in a local zone though it underestimated spatial variation in the whole area.While the advantage of SGCS was to carry out uncertainty assessment for spatial estimate by providing multiple results about probability and reproduce the spatial variability in the whole area.
  • ARTICLES
    Design of Maps for an Atlas with an Example of "The Atlas of Evolution on Population and Environment of The People's Republic of China"
    HAN Jiafu
    2010, 12(6): 777-783.
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    Unlike a single map,the core of map design for an atlas is to compress massive information into serial maps with a logical order in order to convey an overall concept.This article is to introduce the compilation of The Atlas of Evolution on Population and Environment of The People's Republic of China and the characteristics of visualization in map design.Population and environment are two hot topics in China;the atlas summarized and expressed in means of visual map the evolution processes on China's population and environment by drawing on very current research and data as well as the most up-to-data mapping techniques.As a support,merged materials were adopted,which,collected from abundant investigation and research taken by various departments and authorities since the People's Republic of China was founded.On contents design,it deals with population and environment as a whole and sets up a matrix system from five aspects,i.e.population scale and structure,pressures on environment,environmental status,feedback and measures taken to control environmental changes as well as the establishment of a comprehensive database of evolution on population and environment.When design the map it emphasizes visualization characteristics of evolution on population and environment while showing current situation of relevant indicators,and clarifies the relationship between matrix systems through multi-dimension dynamic information map visualizing model in order to reveal the causes of the changes in population,environment,and their relationships.This paper introduces the design if the atlas by means of series maps,changes in structure and quantity,changes in percentage,change in quantity and the relationship involved,change in cumulative quantity,change in cumulative quantity with multiple indicators,changes relative to the annual average values,changes based on a certain point,change in statistical characteristics,and comparison of two periods.In technical aspect,based on basic theory,technology and methods of modern cartology,digital map printing technology were used to improve the quality and efficiency of its compilation and ensure it is up to date.Characteristic of visualization in map design is the main idea introduced by this article.
  • ARTICLES
    Study on the Relationship between Land Use Spatial Patterns and Topographical Factors for Mountainous Region:Taking Jiangxi Province as an Example
    ZHANG Fangfang, QI Shuhua, SHU Xiaobo, LIAO Fuqiang
    2010, 12(6): 784-790.
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    Regional land use has been a hot spot for resource science and Global change researches,and land use change has been taken as one of the most important aspect by most environmental scientists.The mass flux and energy flux are affected by the topographical features such as elevation,slope and aspect especially for mountainous regions,and the land use spatial pattern also showed some relationship with the topographical factors.The ecological frangibility are the concomitant for mountainous regions,and irrational land use can caused ecological hazard such as soil erosion,debris flow,etc.It is important to analysis the relationship between land use spatial pattern and topographical factors in mountainous regions.Jiangxi Province is mountainous and abundant in water and energy resources,but the territorial red soil is infertile,and serious soil erosion can be caused by irrational land use.In this paper,Jiangxi Province was studied in order to find the relationship between land use spatial pattern and topographical factors.SRTM(Shuttle Radar Topography Mission) data was used to extract the Digital Elevation Model(DEM) for Jiangxi Province.The study region was divided into several subareas by elevation,slope and aspect respectively,then the land use structure happened in each subarea was analysed by the spatial analysis functions provided by ArcGIS software.It showed that:(a) the topographical factors are extremely important as they can affect the land use patterns in Jiangxi Province;(b) farmland mainly distributed in regions with elevation smaller than 80m and slope smaller than 3° and it is obvious that farmland area in sunny slope are greater than that in shady slope;(c) area proportion for forest is increasing when the elevation is under 400 meter,and is steady when above 400 meter;and(d) area of grassland has a trend of decreasing when elevation increases,but the area proportion for grassland is increasing slowly when elevation increases.
  • ARTICLES
    Rough Set-Based Research on the Relationship between Traffic Road and Urban Land Use Expansion
    CAO Feng, SONG Hairong, GE Yong, LI Deyu
    2010, 12(6): 791-796.
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    Traffic road plays an important role in transportation and is a major driving force of urban land use expansion.Therefore,traffic road has great impact on urban expansion and development.Also,urban expansion has new demands for the development of traffic road.The relationship between traffic road and urban land use expansion is complex and uncertain,so we need to study it with a variety of research methods and from various aspects.Currently,a large number of mathematical methods and spatial models have been effectively used to analyze the relationship between traffic road and urban land use expansion.In order to analyze the interaction model and impact of traffic road on urban expansion effectively,however,new technical methods should be explored.Rough set theory,proposed by Pawlak in 1982,is an extension of set theory in analyzing data with insufficient and incomplete knowledge and has been demonstrated to be useful in fields such as pattern recognition,machine learning,and automated knowledge acquisition.Rough set theory does not need prior information in analyzing data and can derives the classification or decision rules according to a knowledge reduction procedure while keeping its classification ability unmodified.Thus,rough set theory can mine the objective and inherent rules contained in the data.Rough set theory is still not commonly used in research of the relationship between traffic road and urban land use expansion.In this paper,urbanization of Guangdong Province is taken as an example and the relationship between traffic road and urban land use expansion is studied with rough set theory.The result shows that the decision rules of traffic road and urban land use expansion extracted with rough set theory can effectively reflect the relationship between traffic road and urban land use expansion and can provide some guidance on urbanization researches.
  • ARTICLES
    GIS Based Analysis on Spatial Disparity of Economic Growth in BTHMR
    DONG Guanpeng, GUO Tengyun, MA Jing
    2010, 12(6): 797-805.
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    The aim of the paper is to study the spatio-temporal dynamics of per capita GDP in the Beijing-Tianjin-Hebei Metropolitan Region(thereafter short for BTHMR).A sample of 140 county-level regions over the period 1995-2007 provides clear evidence of global and local spatial autocorrelation or autodependence as well as spatial heterogeneity.Transition probability matrices were used to verify the robustness of our conclusion.Based on techniques of exploratory spatial data analysis,several conclusions are draw as follows:(1) The economic disparity and spatial concentration of the BTHMR is enlarging,as indicated by coefficients of variation and global Moran's I.The economic disparity and spatial concentration have a positive relationship,indicating that with the increase of spatial concentration,economic disparity may also enlarge.(2) With the Moran scatter plot,the heterogeneity takes on two distinct spatial regimes.One corresponds to the HH scheme including Beijing,Tianjin and Tangshan mainly,the other to the LL scheme including mostly Chengde,Zhang Jiakou and Baoding municipalities,which are surrounding Beijing and Tianjin.(3) The annual average growth rates of per capita GDP also reveal high spatial autocorrelation.Regions with relatively high growth rates are localized close to other regions with relatively high growth rates more than if this localization is purely random,and the statistical significant HH cluster falls mainly into Beijing and Tianjin,indicating that at present,the polarization effect rather than the spread effect of growth pole is dominating.(4) The relationship between initial log per capita GDP and average growth rates is different according to various patterns of local spatial autocorrelation of the initial year.In the HH scheme,initial log per capita GDP and average growth rates have a negative relationship,as an evidence of standard β-convergence models,while for LL scheme,the local autocorrelation type of growth rates of most regions remain falling into the LL scheme,indicating that there are no β-convergence.
  • ARTICLES
    Study on Development of Topological Relations among Area Objects Based on Variable Precision Rough Set in GIS
    LIAO WeiHua
    2010, 12(6): 806-810.
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    Spatial topological relations are the hotspot for GIS studies.We introduced rough set theory on the basis of overall analysis of area object topological relations in this text.We took area object of RCC model as equivalence class of Pawlak rough set,when not considering boundary fuzziness and boundary itself,the expressing model of those relations is identical with RCC model.We introduced β most contain factor in the variable precision rough set,and took X as x,Y as X,then X can be expressed as β lower approximation for Y in TPP(X,Y) and NTPP(X,Y) model without considering boundary fuzziness and boundary itself,and Y can be expressed as β lower approximation for X in TPPI(X,Y) and NTPPI(X,Y) model.X is certainly belong to β lower approximation for Y and Y is certainly belong to β lower approximation for X in EQ(X,Y) model.X is possibly belong to β lower approximation for Y and Y is possibly belong to β lower approximation for X in EC(X,Y) model.X is certainly not belong to β lower approximation for Y and Y is certainly not belong to β lower approximation for X in DC(X,Y) model.and these relations are particular case for β=0 in the variable precision rough set.There are common intersect parts of two area objects in PO(X,Y) model,via X∩Y≠φ,then we can divide two area objects into β coefficient including and β coefficient separation by the proportion of the two area objects.So,when the common elemental constituent of X and Y is greater than 50% of X(C(X,Y)≤β),We can obviously get conclusion for Y⊇βX.Therefore,we reach a conclusion that the two area objects of PO(X,Y) have two set expressions Y⊇βX and Y⊄βX in the variable precision rough set,and we mapped POI(X,Y) and PO(X,Y) figure of area object intersect relations in the variable precision rough set.
  • ARTICLES
    Spatial Information Grid Services Based on WSRF and Their Management
    GAO Bingbo, XIE Chuanjie, ZENG Shaobin
    2010, 12(6): 811-818.
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    Applying grid into spatial information area forms the Spatial Information Grid.Spatial Information Grid can aggregate kinds of spatial information resources,perform integrative management,support resource share and provide "on-demand services"."Service on-demand" means to provide diverse services according to the requirements of users,that's to discover spatial information resources or their combinations that satisfy the users' requests,then evaluate them and choose the best ones following some goals to provide service.However,the dynamism of grid environment makes it difficult for users to get current information of the distributed spatial information resources,and reduce the ability to provide reliable "on-demand service".Directly applying the traditional spatial information services into grid cannot overcome this issue.To improve this situation,the plan to design spatial grid services and their management services based on WSRF(Web Service Resource Framework),which is "a generic and open framework for modeling and accessing stateful resources using Web services" and support the separation of states and services is given.The plan is composed of two parts,namely spatial information grid services and the management service.The spatial information grid services are deployed at the nodes that contribute spatial information resources by providing standard accessing services and at the same time organize and publish the state of the resources to be accessed or subscribed following WSRF.The key technologies of how to design the services and the WS-Resource are discussed.The management service is deployed at center node which collects,maintains and manages the information of services and resource state of child nodes and provides access interface to support the resource selection which is necessary for "on-demand service".At last a spatial data grid implementing the plan is described.The spatial data grid contains three kinds of services,they are spatial data grid service,spatial computing grid service and management service.In spatial data grid service,the interfaces are organized complying WFS and four kinds of WS-Resource(service,request,loading and spatial data) are designed.Like spatial data grid service,the interfaces are organized complying WPS and four kinds of WS-Resource(service,request,loading and spatial algorithms) in the spatial computing grid service.The management service is made up of three parts: service register management module,sources and services information management module and public thematic service.
  • ARTICLES
    Study on Communication of Massive 3D Spatial Data Based on ACE
    TIAN Yiping, PENG Yuan
    2010, 12(6): 819-827.
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    Three-dimensional visualization has become a GIS development trend,and it will inevitably lead to an explosion of spatial data,hence the study on storage and management of massive three-dimensional geospatial data is of great significance.The C/S framework,consisting of database of massive three-dimensional geospatial data for server and a large number of normal PC for clients,has become a basic idea to solve the problem.It is deeply discussed and researched how to realize massive three-dimensional data server related technologies in this paper.Based on analysis of the data dispatch of GIS application thoroughly,a protocol of application layer for high-performance network transmission is designed.The layered strategy that based on the ACE proactor framework and thread pool technology was designed to build a transmission framework for massive three-dimensional geospatial data.The I/O strategy to handle the large-customer communication and the concurrent architecture based on it are discussed.Designed server with modular ideas increases the expansivity greatly.The architecture of the object oriented framework is described in this paper,which supports multiple server policy configurations.Because it is a dynamically ordered structure,it can systematically order these strategies and can statically and dynamically change their behaviors.The framework has solved the transmission problem of multi-level cache and concurrent access problem and realized a highly efficient and stable transmission of massive three-dimensional geospatial data.
  • ARTICLES
    Application of Google Earth COM API and KML in Tourism Information System Development
    MA Liguang, CAO Yanrong
    2010, 12(6): 828-834.
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    The development of information technology,especially the development of geographical information system and the open source software has promoted the progress of tourism information system.With the enhancement of awareness of ecological and environmental conservation,eco-tourism has been gradually integrated into tourism information management fields and this extended the scope of tourism information system.Based on the free Google Earth COM API and the open KML data standard,the development methods of tourism information system were discussed in this paper.Application of KML based data model helps to organize/manage and classify tourism data hierarchically.Methods of using the Google Earth 3D Digital Earth platform interface to realized the visualization of tourism landscape and resources were introduced.The developing skill about the tourism resources retrieval,searching and spatial position function as well as the landscape resource touring means with Google Earth COM API on 3D platform was explained in detail.Finally,the authors have designed the tourism information system by integrating Google Earth COM API with C#.NET,which has the capability in tourism information query and browse,and customized touring for both public and tourism manager on an independent software package.The development skill and experience as well as the matters need attention in developing process were summarized.The practice proved that the application of Google Earth COM API components and KML data specification for tourism information system development and tourism data management is feasible and effective.The example,method and key points provide in this paper are repeatable to other programs.
  • ARTICLES
    Monitoring Inter-annual Vegetation Variation in Middle Inner Mongolia through MODIS NDVI
    WANG Junbang, TAO Jian, LI Guicai, ZHUANG Dafang
    2010, 12(6): 835-842.
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    In this paper,we investigated the response of inter-annual vegetation variation to climate change in middle Inner Mongolia based on 250m MODIS NDVI data in 2000-2008 and climate data from meteorological stations during 1960-2008.After applying S-G filer process to deduct the noisy and abnormal points,the mean of 8-day NDVI in a year was calculated to indicate the vegetation status in that year.Then the trend of inter-annual vegetation variation in 2000-2008 was calculated with the linear regression coefficiency,that is the slope of a line,and analyzed through the regression significant level.The average NDVI by vegetation type was calculated according to vegetation map with a scale of 1:100 000.During the study period,79.60% of the vegetation area keeps a relatively steady state,and 17.33% changes to better.But 3.06% of the grassland is in degradation or desertification where is in the Farming-Pastoral Transitional Zone.The climate factors that caused inter-annual vegetation variance were quantified.The warmer and dryer climate change happened in this region was regarded as main reason.Between two climate factors of temperature and precipitation,the variance of precipitation has more effect on the change of NDVI than temperature.The ratio of standardized regression coefficients of precipitation and temperature is in range of 0.89(Suolun) to 11.50(Siziwang Qi).At Xilinhot,the ratio is negative which may be explained as combined influence of unmatched temperature and precipitation.However,the inter-annual variance of grassland was affected not only by climate,but also by human activity.In this paper,however,the latter factor was not analyzed though it is very important for assessing the technique on ecosystem protection and recreation.Quantificationally assessing the effect of human activity under global climate change is an interesting and challenge research field for us in future.
  • ARTICLES
    Evidential Reasoning Remote Sensing Image Classification Method and Application
    WU Yan, LI Huapeng, WANG Yuguo
    2010, 12(6): 843-849.
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    Remote sensing classification is always a core problem in the remote sensing research field.However,traditional classification method should be caught into question when the context information is complex.Besides the classification accuracy is not ideal,there is also a classification flexibility problem.This paper introduced an evidential reasoning "soft" classification method which has a high degree of flexibility for classification.The results can be adjusted easily for improved classification accuracy based on users' knowledge and experience combined with visual interpretation.We chose a TM image of Xiaoxinganling mountain area to assess the performance of evidential reasoning classification method.The TM image spectral characteristic of typical surface categories of the study area was analyzed,and the results showed that the spectra overlap phenomenon was serious for each band.We chose the 4,5,7 band with light spectra overlap phenomenon as evidence sources.Through the combination rule of evidence,we got distribution maps of cumulative belief value for different categories.Then we produced a theme classification map with the maximum cumulative belief value as pixels divided rule.We compared classification accuracy between maximum likelihood classification(MLC) and evidential reasoning(ER) based on confusion matrix,and the results illustrated that the overall accuracy improved from 78.74% of MLC to 82.28%,the kappa coefficient also improved from 0.67 to 0.71.For a better accuracy,we set different CBV thresholds of different categories based on visual interpretation and "soft" classification mode,and produced a higher classification accuracy map with 87.80 % overall accuracy and 0.81 kappa coefficient.This study proved that the evidential reasoning method has more advantages than traditional the method,not only in its classification accuracy,but also in its flexibility in remote sensing classification processing.
  • ARTICLES
    Vector Edge Extraction from Multi-Spectral High Spatial Resolution Remotely Sensed Imagery(MHSRRSI) Based on Multi-Color space
    LIU Jianhua
    2010, 12(6): 850-854.
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    MHSRRSI has much more rich spectral information for detecting edges than single band imagery,and thus flexibly selecting tactics on edge detection and extraction according to feature properties is more important.Since its advantages in detecting edges from monochrome imagery,Canny operator is improved by means of the strategy of output fusion so as to be suitable for detecting vector edges from MHSRRSI.The improved Canny algorithm contains the following steps.Firstly,in order to effectively wipe off geometrical details and mini-spot noise in the inner of geographical semantic feature object,we apply the Gaussian smooth filter to the original imagery.Secondly,we get the multi-dimension gradient vector imagery based on the smoothed imagery.Thirdly,we utilize the method of non-maximum restraining to acquire the primitive vector edge imagery based on the gradient vector imagery.At last,we use the technique of couple thresholds to gain the finally vector edges from the primitive vector edge imagery.Based on Visual VC++.NET platform,the algorithm is implemented to effectively extract vector edges in the multi-color space from the study area in Fuzhou.Because of discrepancies among the spectral range of those components of MHSRRSI,it will result in remarkable differences of response extent of edge detection among different kinds of geographical features.The response extent of edge detection among different kinds of geographical features in multi-color space is also analyzed.The conclusions of this article benefit feature selection for edge detection among different kinds of geographical features and the subsequent edge extraction.Meanwhile,it indicates that the parameter and the selection of color space will give remarkable impacts on the extraction of vector edges.
  • ARTICLES
    Monitoring and Analyzing Urban Landscape Pattern Change Using Beijing-1 Small Satellite Remote Sensing Data:Taking the Urban Area of Xuzhou City as an Example
    DU Peijun, SHAN Dandan, XIA Junshi, LIU Pei
    2010, 12(6): 855-862.
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    In order to push the applications of Beijing-1 small satellite remote sensing data to urban landscape ecology studies,the panchromatic high resolution data,medium resolution multi-spectral data and fused data of panchromatic and multispectral images of Beijing-1 were used to analyze urban landscape pattern from class level to landscape level.By comparing different classifiers,support vector machine(SVM) was selected to classify the land cover and landscape component types,and spectral and textural features were integrated to improve classification accuracy.After a comparison to some fusion algorithms including IHS,Brovey,PCA and Gram-Shmidt algorithm,we chosen IHS algorithm to fuse the panchromatic and multispectral images.The classification results of multispectral images on two dates were employed for landscape change analysis at first,and the results showed that the landscape from 2007 to 2008 had obvious changes,which were also evidenced by the statistics of landscape metrics from landscape level to class level.By comparing the landscape pattern indices derived from panchromatic and multispectral images,we can find that the overall properties keep similar on two data sets,but 4m panchromatic image was good for revealing more detailed features,and the 32m multispectral images were effective to show the overall trends and patterns.The fusion image of panchromatic and multispectral images outperform any individual data sets in analyzing urban landscape pattern owing to the combination of high spatial resolution and multispectral capacity.The results show that Beijing-1 small satellite remote sensing data are effective to monitor and analyze urban landscape pattern,especially,the band allocation of 4m panchromatic image and 32m multispectral images can describe and reveal the landscape pattern and process on different levels.
  • ARTICLES
    Optimization and Application of Object-oriented Information Extraction Methods Based on Geographic Understanding of Remote Sensing Images
    XU Xiao, YANG Xiaomei, GONG Jianming
    2010, 12(6): 863-869.
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    In the academic domain of remote sensing information extraction,per-pixel spectral classification and object-oriented classification method are two main approaches.Presently,the application scope of object-oriented classification method is becoming enlarged so as to meet various needs of image processing and information extraction towards diverse ground objectives.The object-oriented method has been a useful helper in many cases;unfortunately it has not developed into a great approach.In fact,several problems have been spotted when applying object-oriented methods.This paper intends to deal with the problems in executing object-oriented information extraction and proposes a new concept,which is to combine the per-pixel classification and object-oriented classification,based on above mentioned delicate problem-studying.The methodology of this paper is presented as follows.To begin with,the priori regional knowledge is first obtained by means of geographic analysis based on traditional per-pixel maximum likelihood classification.By doing this,the spectral confusion between different types of ground objects and the complexity of the whole image can be described both quantitatively and qualitatively,in order to reflect the difficulty and technological requirements regarding image processing and information extraction.Subsequently,the knowledge gained via pre-analysis is then used to direct the technique taches in image processing,as well as to optimize the segmentation parameters and the classifier construction in the workflow of object-oriented extraction.A major objective of the abovementioned technique is to conquer the blindness of parameters setting and the multiformity of segmentation results.Finally,compared to the object-oriented result without the support from geographic understanding and analysis,this proposed method is proved good at partitioning the real elementary objects and improving the classification accuracy,efficiency and the training performance.
  • ARTICLES
    Information Extraction of Karst Rocky Desertification Using Remote Sensing
    HU Shunguang, ZHANG Zengxiang, XIA Kuiju
    2010, 12(6): 870-879.
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    China South-western karst rocky desertification has been more and more concerned due to its increasingly far-ranging influence on economical society and ecological environment.By remote sensing,a wide range of rocky desertification information can be practicably obtained.However,information extraction of rocky desertification based on remote sensing is not just an isolated technology,but a process of comprehensive analysis and feedback.To further explore the technology on information extraction of rocky desertification,this paper is mainly related to illustrating current developing of information extraction technology on rocky desertification,and on the basis of this,a new strategy for information extraction of rocky desertification has been raised.Specifically,we firstly analyze current researches of rocky desertification classification system,and then make a comparison between karst area and rocky desertification region.Furthermore,we illustrate the relationship between land use and rocky desertification,and summarize the current key technology of extracting rocky desertification information.Finally,we have drawn four aspects of conclusions as following: Firstly,due to huge differences in the aspects of classification amount,classification index and classification regions in current classification system of rocky desertification,it is useful to introduce the scale division method into the system,which can unify different classification types of rocky desertification levels.Secondly,the content-based characteristic discerned algorithm is a helpful research taste for karst area extracting,which can raise the precision of extracting rocky desertification information at last.Thirdly,it is an important way to transfer land use vector data into rocky desertification information by rationally using the corresponding relationship between different types of land use data and different rocky desertification levels.Fourthly,traditional research methods that building rocky desertification symbol,improving vegetation index model or establishing spectrum relationship model to extract rocky desertification information cannot well compromise the comprehensive characteristics of rocky desertification,so an extraction method based on rocky desertification comprehensive index has been put forward as a result.
  • ARTICLES
    Useing Digital Photography to Measure Vegetation Coverage in Qinghai-Tibet Plateau
    JIA Jianhua, HU Yong, LIU Liangyun
    2010, 12(6): 880-885.
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    As an important indicator of vegetation,vegetation coverage,which is generally estimated by visual measurement,is always used as an important index in vegetation evaluation and a key parameter for remote sensing inversion.But this method strongly depends on individual variables,and without the reproducibility of the results.That is to say,different observers almost certainly record different measurements with the same quantity.The advent of digital photography and automated image processing promises a revolution in the way vegetation coverage is measured.Recently,an automatically extracting algorithm for vegetation coverage was studied based on color features and some threshold values,and have a high accuracy when it is used to calculate the winter vegetation coverage with vertical digital photographs.However,this automatic method isn't suitable for Tibetan Plateau due to its various types of vegetation and background.Though analyzing on the color characters of vertical photographs,we found a named excess green method,which is sensitive to green vegetation and enhances the contrast between plant and soil background.A k-means clustering algorithm was designed to divide photographs into plant and background,and calculate vegetation coverage automatically.Compared with the result from the manually supervised classification method,the root mean square error was less than 5%,but it spend less time than supervised classification and had a higher accuracy than that of visual methods.Moreover,some approaches to improve classification accuracy were discussed by analyzing the error source of automatic classification.
  • ARTICLES
    Extraction of Structural Line Features of Tomb Sites Based on Remote Sensing Data:A Case Study in Wuling Hills of the Western Han Dynasty,Shaanxi Province
    2010, 12(6): 886-891.
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    At present,it is widely believed that remote sensing technology is an important means for modern archaeological research.When remote sensing technology is used to assist in archaeological research,it can not only give us more effective means of scientific analysis,but also opportunities to discover or recover the historical monuments that traditional ways can not achieve.In contemporary remote sensing archaeology single source of image data are always used,which recognize the ground or underground ancient ruins with visual interpretation according to expert experience by remote sensing data analysis on the basis of landscape morphology,surface features shadow,frost or snow,land temperature,vegetation and various signs.In this study,high-resolution image DOM,ALOS multi-spectral data and QuickBird fused data are used in detecting tomb archaeological remains in Wuling Hills,Shaanxi Province.Structural line features are extracted based on image fusion algorithms and edge detection algorithms.The results show that: firstly,compared to single data source,the image fusion based on multi-source data can not only maintain the spatial detail of high-resolution images but also the spectral signature of multi-spectral images.Hidden line features can be enhanced by image fusion obviously.It can be a valuable approach for extraction of structural line features of the site.Secondly,the amount of spatial information and spatial distribution patterns will be different based on different spatial resolution and image fusion methods.In term of line feature extraction of the remains,higher resolution does not mean a more suitable data resource to the archaeological research.The fusion of DOM,ALOS+NDVI images based on Gram-Schmidt algorithm is the most effective method for structural line features retrieval.Finally,the edge detection method will enhance the linear characteristic of the remains.The explicit and a large number of implicit linear characteristics can be obtained by edge detection method using Canny algorithm.It is an important indicator for inspection and interpretation of the remains.