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  • 2009 Volume 11 Issue 3
    Published: 25 June 2009
      
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  • ARTICLES
    Spectral Identification and Inversion of Composition and Component of Objects with Hyperspectral Remote Sensing
    WANG Runsheng
    2009, 11(3): 261-267.
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    The principal advantage of hyperspectral remote sensing is to identify composition and components in objects and inverse the physical and chemical parameters according to the acquired and rebuilt pixel spectral signatures.This paper reviewed the composition and components of rocks,soils,atmosphere,vegetation,water body and manmade structures that can be recognized with hyperspectral remote sensing,described spectral identification methods and then,discussed some key characteristic techniques comparing with multispectral remote sensing,such as spectral matching,spectral unmixing,endmember selection,and quantitative inversion as well.
  • ARTICLES
    Application of New Types of Remote Sensing Technology in Uranium Deposit Prospecting
    LIU Dechang, YANG Xu, ZHANG Jielin
    2009, 11(3): 268-273.
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    With the development of remote sensing,there are a few new types of sensors from which can acquire abundant new types of remote sensing data.These data have been applied successfully in many different fields of national economy.In this paper,applications of four new types of remote sensing data in uranium deposit prospecting,i.e.multi-spectral,high-spatial-resolution,hyperspectral and radar data,have been summarized.
  • ARTICLES
    Discussion on Applicational Comparison between New Type of Multi-spectral ASTER Data and ETM+ Data:A Case Study on Extracting the Reduced Alteration Information of Gas and Oil in Bashibulake Uranium Ore District
    YE Fawang
    2009, 11(3): 274-281.
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    Based on analyzing the spectral characteristics of the reduced alteration sandstone of gas and oil in Bashibulake uranium ore district,and the difference in illustrating the spectral feature between ASTER and ETM+ data,two kinds of technologic ideas were proposed to study the remote sensing reduced alteration information directly and indirectly.Following the two ideas,different effects in using ASTER and ETM data were compared respectively.Studies showed that both ASTER and ETM had equal and good effect in extracting the ferric information to reflect the law of reduced alteration of oil and gas indirectly,but in aspect of extracting the reduced alteration information,ASTER data showed obviously better effect than ETM+.Those enhanced reduced alteration information was of great significance in addressing the alteration law in Cretaceous system and uranium prospecting in the outer parts of Bashibulake uranium ore district.
  • ARTICLES
    Research on Background-Anomaly Sub-space Model of Hyper(Multi-) spectral Data
    ZHANG Yuanfei, YANG Zian1, ZHANG Pubin, SHI Feifei, ZHANG Jianguo
    2009, 11(3): 282-291.
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    The article quoted a number of important theory thoughts of independent component analysis and blind signal separation,classified and explained the distribution of probability density from the basic statistical characteristics of remote sensing hyper(multi-) spectral data and,established the connection between background and anomaly of image data.On this basis,it deeply analyzesed the spatial geometry structure of hyper(multi-) spectral data lattice distribution,concluded that high-dimensional space of remote sensing hyper(multi-) spectral data belong to low-dimensional geometry structure-"hyperplane" shape,and anomaly point group which includes alteration information usually dissociates out the "hyperplane".Then,the paper extended the signal-noise model of principal component analysis(PCA),proposed the dividable concept of background-anomaly signal sub-space of remote sensing image multi-data set high-dimensional,and gave the threshold estimated method of sub-space division.At the same time,it discussed the relationship among the pixel number of remote sensing image,the intrinsic dimension of multi-band data set,and the main background object number.Finally,through analysing two types of remote sensing data for Qulong area,Tibet,it explained the correctness and practicality of spectral data space low-dimensional structure and the application of analysing remote sensing hyper(multi-) spectral data to background-anomaly sub-space model.The results show that: although the spectral change of different landscape areas is complex,the low-dimensional geometry structure which spectral data space belongs to,and the practicality of background-anomaly(including noise) sub-space are the essential characteristics which they all possess.In a statistical sense,the alteration anomaly of remote sensing hyper(multi-) spectral data set is identifiable.
  • ARTICLES
    VGEs-Oriented Multi-sourced Heterogeneous Data Integration
    SU Hongjun, SHENG Yehua, WEN Yongning, CHEN Min
    2009, 11(3): 292-298.
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    Virtual geographic environments(VGEs),which as the opposite of the real environments are the reflection of real environments in mental scene.It is not just a framework which emphasizing data sharing in GIS,and has become a knowledge sharing platform which emphasizing both database and model database simultaneously.As a research platform for earth system science,VGEs are oriented to geographic investigation and analysis of multi-domains.It is a very meaningful tool for geographic modelling,simulation and geographic problem solving.The world of today heavily relies on spatial data to manage the natural and built environments,also to construct VGEs.In this paper,the characteristics of mutli-sourced heterogeneous spatial data in VGEs were discussed,and heterogeneity in spatial data can be divided into five types,namely data values,schema,data model,syntactic and semantic heterogeneity.A Data Representation Model oriented to VGEs(DRM) which provides a common data model to define a data representation structure for traditional data and spatial data was designed in this paper.The DRM not only provides a clear description of geographic data,but also defines the relationships between geographic data.The processes and framework of mutli-sourced heterogeneous spatial data integration were proposed based on the above discusses.The integration consists of the following subparts: geographic data parsing,interaction between geo-data and geographic model,and geographic model parsing,running and results output.Also,spatial data parsing and the communion between mutli-sourced heterogeneous spatial data and geographic model were discussed especially.Lastly,the platform system of multi-sourced heterogeneous spatial data integration was designed and developed under the VS.NET2005 development environment combined with XML technology,and it can solve the bottleneck problems arise in geographic information resources which under heterogeneous environment.Some experiments were designed and discussed,and the results show that the platform we developed can be integrate multi-sourced heterogeneous spatial data effectively and can work better than other similar platform systems.
  • ARTICLES
    Using Remote Sensing Data to Monitor Landslide-dammed Lakes Caused by Wenchuan Earthquake
    PAN Shibing, LI Xiaotao, SONG Xiaoning
    2009, 11(3): 299-304.
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    There happened a scale of 8 on the Richter calculations earthquake in Wenchuan County,Sichuan Province on May 12th of 2008.It caused a lot of landslides in Beichuan County and many landslide-dammed lakes had been formed,some of the lakes are at very urgent risk of dam breaking and would threaten downstream people.Results of an investigation on landslide-dammed lakes are analyzed after Wenchuan earthquake using various types of remote sensing data including aerial,visual,and SAR satellite data.This paper discusses the general role of distribution and variation of landslide-dammed lakes.The dynamics of the Tangjiashan landslide-dammed Lake,which is the largest one,is analyzed in detail.Area changes of the Tangjiashan landslide-dammed lake in different periods,including the course length and the water surface area of inundated region are obtained from images between May 14th and 26th.The course length and the water surface area were about 7.39km and 1.14 km2 on 14th May,respectively.By 26th May,the course length and the water surface area reached 17.6km and 4.09km2,respectively.The results provided basic information for disaster reduction of the landslide-dammed lakes in this region.
  • ARTICLES
    Thin Cloud Cover Removed from High-Resolution Remote Sensing Images Based on the Adaptive Filtering and Gray-scale Transformation
    HE Hui, PENG Wanglu, KUANG Jinyu1
    2009, 11(3): 305-311.
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    There are sometimes some uneven thin cloud-fog effects in the remote sensing images from optical remote sensors,especially in cloudy and rainy areas.A new method based on adaptive filtering and gray-scale transformation was proposed to remove the cloud-fog cover of the high-resolution remote sensing images in this paper.This comprehensive technology program was applied to process the SPOT5 image with heavy thin cloud-fog cover acquired from Zhuhai,China.And to test its superiority,a comparative experiment with two other available methods named homomorphism filter and an approach based on Laplacian enhancement and histogram transformation was carried on.Several objective indicators,such as PSNR(Peak Signal-to Noise Ratio),average absolute deviation and spectral correlation coefficient(proposed by Li Yuechen[1]),were used to evaluate the resulting images.Besides,to verify the general reliability of the framework proposed,more image data from different sensors,such as TM and CMB satellite,in the cloudy and rainy areas were selected for the corresponding experiment.The results indicate that the experimental results for different data source are consistent,which show that the proposed integrated methods can remove the thin cloud-fog cover effectively and maintain the true spectral features of the original image to a large extent.Furthermore,as a result of the application of different parameters of filtering and gray-scale transformation for different spectral band,the spatial details and true spectral information are remained as more as possible.
  • ARTICLES
    Dynamic Monitoring on Water Level of Angulinao Lake and the Causes of Its Drying up
    ZHAO Yuling
    2009, 11(3): 312-318.
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    Angulinao Lake is located in Zhangbei County,Hebei Province.It is the largest lake formed by continental rivers in Haihe basin.The lake covered up to 18000 hm2 when it was the largest.And it was getting completely dry in recent years.Based on MSS\TM\ETM\CBERS-1\CBERS-2 remote sensing data and GIS Technology;this paper studied the evolution of the water level of Angulinao Lake from 1975 to 2007.The results showed that the surface area of Angulinao Lake changed greatly,while the upriver reserviors changed little.The surface area of the lake is about 4300hm2 in 1975,changed to about 5100hm2 in 2000,and then reduced the scope every year.These changes corresponded well to the climate changes in northern China and to the changes of upriver discharge capacity during the same period.Dry climate and the weak period of the upriver discharge capacity responds to the period of small surface area;while damp climate and the strong period of the upriver discharge capacity corresponds to large surface area.The study also showed that the Eco-environment has degraded in recent years.The salinized area had increased about 170km2 from 1977 to 1987,and increased about 120km2 from 1987 to 2007.These changes corresponded well to the surface area changes of Angulinao Lake.The causes resulting in drying up of the Angulinao Lake have been studied.The geological factors,such as faults,strata,earthquake,have no influences on it.The main reasons are climate change and human's activities,such as the excessive interception of upriver reserviors and over extraction for groundwater.Dry climate and lower upriver discharge capacity are the killers of the Angulinao Lake.To keep balance between economic development and environmental protection,there is a long way to go.
  • ARTICLES
    DEM Construction and Application Based on HASM
    CHEN Chuanfa, YUE Tianxiang
    2009, 11(3): 319-324.
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    High Accuracy Surface Modelling(HASM)constructed on the base of fundamental theory of surfaces is more accurate than the classical methods for surface modelling.However,the traditional solving method for HASM is to employ an invariable resolution to simulate the whole computational domain,which causes a huge computation cost and an enormous amount of data.In general,under the same amount of sampling points,the accuracy of HASM depends on mesh spacing.The finer the finite-difference mesh,the more accurate the solution is.Unfortunately,due to limitations in computational resources,it is often impossible to use a single uniform mesh to solve a given problem to the desired accuracy.On the other hand,it is often the case that the finest resolution is only required in regions which only make up a small fraction of the computational domain.Computing an unnecessarily fine solution outside these regions represents a waste of computational resources.Adaptive mesh refinement method can select the simulation resolution adaptively with the terrain complexity or accuracy requirement,which places more grid points in regions where the terrain is complex,while using fewer grid points in flat regions.Based on the adaptive mesh refinement theory,we constructed the adaptive algorithm of HASM.Dongzhi tableland was selected for validating the effectiveness of HASM.The results show that the adaptive algorithm of HASM reduces much computation cost and data volume under the same accuracy of traditional HASM.
  • ARTICLES
    A Study on the Method of DEM Generation from Contour line Using HASM
    SONG Dunjiang, YUE Tianxiang, DU Zhengping
    2009, 11(3): 325-332.
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    DEM can be constructed from many kinds of data sources among which traditional contour lines from manual interpretation of landforms is still a nontrivial ones.This paper proposed a new method to construct DEM from contour lines based on the HASM(High Accuracy Surface Modelling) which used to handling discrete points only.Firstly,a regular grid points' are set up,on which each elevation will be predicted using the new method,each grid point represents the square grid area surrounding itself.Secondly,contour lines are discretize according to several rules: a) if a grid is traversed by a contour line,then the distance from the center point of the grid to the contour line will be computed,and if the distance is less than or equal to one-fourth of the side length of the square grids,this grid will be set with values of the contour line's height;otherwise,this grid will be not set with values;b) if four connected grid points whose grids were traversed by a contour line,and their distances to the contour line are greater than one-fourth of the side length,then the last grid point will be set with values of the contour line's height.Numerical surface based on Gaussian synthesis is used as an example,setting up grid points with extent of x,y∈,75×75,and contour lines are derived from true numerical results in ArcGIS 9.0.Then these methods,such as Thin Plate Spline(TPS),TIN(Triangular Irregular Network) and HASM are used to construct DEM from the derived contour lines.Resulting DEMs are used to derive contour lines,which shows that contours from HASM are of most fidelity to the original contours,then the TPS and TIN.There is only one artifact contour line for HASM method,while two contour lines are missed on peaks and a contour missed on the saddle for TPS,altering the basic shape of the terrain.TIN has preserved the basic shape of the terrain,but it has produced zigzag contour lines and even illogical discontinuous contour lines.The result and method proposed in this paper is useful for further studies on HASM method and related contour line researches,such as contour-based terrain analysis.
  • ARTICLES
    Geographic Problem-Solving Oriented Data Representation Model
    CHEN Min, SHENG Yehua, WEN Yongning, SU Hongjun, GUO Fei
    2009, 11(3): 333-341.
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    Extensible Geographic Environments(XGE) is a collaborative modeling environment which is designed for cooperative modeling by experts from different domains.In order to solve the problem of using multi-source heterogeneous data in XGE,a data representation model which named as XGE-DRM is proposed in this paper.Based on study of expression approach and organization criterion about multi-source,heterogeneous and multi-domain geo-data,XGE-DRM is divided into two levels,i.e.: the atom representation level and the object representation level.Prototype,semantic,metadata,expression,spatial reference and unit about data expression are discussed in atom representation level,and the expressions about relationships among data are also mentioned.The expression of geo-Entity is studied in the object representation level considering atom expression.In this level,each Entity has different aspects;each aspect is designed for different research domains,and can be saved as template with XML technology for reuse.Based on XGE-DRM,data construction and semantic can be parsed by a uniform way,and can be explicitly expressed.Owning to legible expression for data construction and semantic,geo-data can be shared expediently by different actors in collaborative modeling environment such as data owner and model builders who expressing their data and converting data from different kinds of data which is heterogeneous.Lastly an experiment about groundwater mining was designed in this paper;it involves integration of time series model and groundwater model.The experiment has shown that this XGE-DRM can meet the requirement of commom expression and efficiently using of geo-data,and it can support the geographic problem-solving oriented modeling environments.
  • ARTICLES
    Equivalent Elliptic Nested Structure and Its Application in Variogram Nesting
    ZHANG Shuo, LU Xuejun, ZHAO Yingjun, ZHANG Chunxiao
    2009, 11(3): 342-348.
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    Existing business software of Geographic Information System(GIS) generally could not take the function as a Geostatiatical Analyst.Even if some of them can do this,it is just at the level of simple variogram calculation and basic variogram nesting method,which hardly fit the need of spatial analysis for spatial variance quantitative analysis,and from the perspective of industry application,it also can't meet the requirement on analysis precision.Taking the biggest GIS technology providing company-ESRI as an example,its product-ArcGIS have a tool in its Toolbox called Geostatiatical Analyst Tool(GAT),but it is weak at the link of interaction between user and computer.So it is inevitablly troublesome that variogram with outlier can't be nested appropriately.And this tool can only handle 2D data,and can do nothing for 3D data.This paper analyzes the need of spatial analysis in 3D data set and common nest methods,including simple variogram nesting method,equivalent elliptic variogram nesting method and so on,and compares the difference and applicability of them.In focusing on the equivalent elliptic variogram nesting method,it is found that by some modification,equivalent elliptic variogram nesting method can be used in 3D environment,and can output a reasonable result.After that,this paper studies the cross validation in order to test whether the result is accurate enough,and discuss the Kriging variance for testing the result of equivalent elliptic variogram nesting method.Finally,with some drilling data and mineralization information,this paper calculates the variogram of X-axis,Y-axis and Z-axis,and with adapted equivalent elliptic variogram nesting method,have the result.After Kriging interpolating and cross validation,with kriging variance,there come to a conclusion that the result from equivalent elliptic variogram nesting method is acceptable.
  • ARTICLES
    Geographic Epidemiology Methods for Analysis of Disease Outbreaks in An County after Wenchuan Earthquake
    YAN Lei, REN Yuhuan, CHEN Cheng, YAO Jianyi, CHEN Wei, HUANG Xiaoxia, WANG Shiwen
    2009, 11(3): 349-354.
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    At 2∶28 p.m.on 12 May,2008,a devastating earthquake measuring 8.0 on the Richter scale hit Wenchuan County,Sichuan Province in southwest China,and resulted in death of thousands of people.The author went to An County that located close to Beichuan County as an emergency response team member of public health.Some geographic epidemiological methods were used to explore the geographic features and distribution of the diseases and high risk population in An County after Wenchuan earthquake.Thematic maps,curves and statistics tables were developed.The methods are tools to help public health workers to understand the sanitation situations after earthquakes visually,gradually and directly.According to the results mentioned above,the discussion on geographic epidemiology methods has been carried out from different aspects,such as their inherent advantages,key points and modes of their implementation,and the direction of further study in the field.The important conclusions obtained are:1)the successful usage of the geographic epidemiology is relied on the quality of epidemiology data with positioning accuracy,the frequency of updating and completeness of content;2)the targets of the study in the field must extend from the outbreak description to the forecasting of the outbreaks and decision making for their control and prevention as soon as possible;3) dynamic method will be used in future studies to demonstrate real in situ circumstances on time;4) decision support,early warning and forecasting will be the new outcome of the geographic epidemiology.It will be done in future studies.
  • ARTICLES
    Evaluation Measures of Web Maps and Their Application
    ZHANG Xueying, SHEN Qijun, LONG Yi
    2009, 11(3): 355-362.
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    A web map is a web-based service on the Internet that provides maps for users to search and browse spatial information,such as place locations and routes.With the increasing development of Internet,web maps have become popular on the Web due to their convenience,low cost,and dynamic characteristics.The evaluation of web maps is useful to improve the services of web maps and their popularization.The previous methods considered only parts elements.Moreover,it is difficult to quantitatively compute the performance of web maps with them.To overcome these problems,this paper discusses four hierarchical elements correlated to the performance of web maps.Based on the assumption,an evaluation system with the definition of 39 measures is proposed,and then the quantitative and qualitative evaluation approaches are described.Finally,nine Chinese web maps such as MAPbar、MAPabc、Baidu、51map、Google Map、Microsoft Live search、Sougou、Aiwen、Yahoo are analyzed with these measures.The results indicate that 51map achieves the best performance,Google map provides the best interface but with lower performance because of the shortage of data.In conclusion,there are still many problems in Chinese web maps,especially standardization of named places,natural language search,and incompletion of map data etc.
  • ARTICLES
    Research on WebGIS Based Basin Flood Management System
    WAN Hongtao, CHENG Xiaotao, HU Changwei
    2009, 11(3): 363-369.
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    WebGIS based Basin Flood Management System is an advanced high technology based platform for supporting the large river conservancy commission in flood forecasting and warning,emergent operation of flood works,flood damage assessment,flood water utilization,and decision making for flood fighting.Based on Computer,internet and intranet,WebGIS,Datebase software,hydrological and hydraulic model,flood damage assessment model,the WebGIS based Basin Flood Management System is designed and developed.In this paper,firstly the framework of the basin flood management system is discussed in detail,then the database structure and the hydrological and spatial data introduced.As a pilot project,Songhuajiang Basin Flood Management System is developed.Its function includes the basic flood information management,flood monitoring and warning,flood forecasting and works operation,2D flood simulation,flood damage assessment,and flood fighting management.The analysis models include Songhua River Basin Flood Real-time Forecasting model,which consist of Basin Rainfall Runoff Simulation based on MIKE NAM and 1D River Network Hydrodynamic Simulation based on MIKE11 HD,and Flood Damage Evaluation Mathematical Model,2D Flood Simulation Model based on MIKE 21 model in four important City and 2 Flood Detention Basin,and flood damage estimation model.As the first Basin Flood Management System in China,the issue and experience for design and development of Flood Management System is helpful for further researches.
  • ARTICLES
    Tobacco Geographic Information System based on Spatio Temporal Feature Analyzing Technique
    GUO Jifa, LIU Zhen, CUI Weihong
    2009, 11(3): 370-375.
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    The tobacco geographical information analysis system is important for tobacco planting,production and distribution.The necessity and application requirements were analyzed.In.Net framework,this system was built by using ArcEngine and ArcSDE which is Client/Server structure,and Oracle was used as spatial database and vb.net as the language.The system structure and realized functions were introduced;these realized functions include map services,tobacco geographical information query and statistics,tobacco geographical information spatio-temopral analysis and decision-making.Some crucial techniques were summarized at last,including spatio-temporal database,tobacco spatio-temporal event analyzing model based on spatio-temporal serial and Web services and so on.The spatio-temporal data include two types: business data and district data.For the district data,the life circle of a district and the changing events should be recorded at the same time.The historical data of one district can be gotten through the district changing table,and then spatio-temporal analysis could be realized.This system had profound influence in tobacco planting and management.
  • ARTICLES
    Design and Development of Flood/Waterlogging Disaster Risk Model Based on ArcObjects
    LIAN Jian, GONG Huili, LI Xiaojuan, ZHAO Wenji, HU Zhuowei
    2009, 11(3): 376-381.
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    China often suffers from different natural disasters,especially flood and waterlogging,so,risk analysis and assessment of flood disaster is an important part of flood control and disaster mitigation.As current risk analysis process of flood disaster are cumbersome generally,in this paper we proposed a method to develop a flood/waterlogging disaster risk model.This method considers the characteristics of watershed flood disaster,chooses some important influence factors,and adopts the ArcObjects development language,AHP method to construct a flood disaster risk model based on the COM component framework.With this risk analysis model,the effects of each factor to flood disaster are quantified,map of flood disaster distribution and condition of flood disaster vulnerability distribution are achieved respectively.In the end,we take Dongting Lake region as a case studying area to test the flood disaster risk model.The results show that the model is easy to be operated,and has a better effect for regional flood disaster risk analysis.
  • ARTICLES
    Process of Transformation from Wetland to Farmland and Driving Mechanism Analysis in Luobei County of Sanjiang Plain
    HUANG Ni1, LIU Dianwei, WANG Zongming, ZHANG Bai, SONG Kaishan, LI Fang, REN Chunying
    2009, 11(3): 382-389.
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    Based on RS and GIS technology,six periods of land use data in Luobei County of Sanjiang Plain since 1954 were obtained.By the methods of GIS spatial analysis and landscape pattern analysis,the process of transformation from wetland to farmland in the study area in the past fifty years was analyzed.From both natural and human factors,driving mechanism of transformation process from wetland to farmland in study area was discussed.The results showed that wetland is the main source of emerging farmland.Farmland transferred from wetland accounts for 93.51% of emerging farmland area from 2000 to 2005 and the annual velocity is the rapidest in all the six periods.Spatially,wetland patches become more and more dispersed and wetland landscape fragmentation becomes more and more serious.Meanwhile,farmland has the trend of connecting into each other.Now,farmland has become the basic landscape in study area.Transformation from wetland to farmland is easier to realize in the Plain which has low and flat terrain,relatively small slope angle,good soil and landform conditions.With the decrease of wetland resources,people begin to reclaim wetland landscapes which have relatively worse terrain,soil,and landform conditions.Climate warming accelerates the step of transformation from wetland to farmland.Population growth and the guiding role of policy have important influences on process of transformation from wetland to farmland in study area.
  • ARTICLES
    Analysis on the Characteristics of Land Cover Change in Nature Reserves in the Three River Source Region during Recent 30 Years
    CHEN Hao, ZHAO Zhiping
    2009, 11(3): 390-399.
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    Using three-phase land cover data(i e,late-1970s,the end of 1980s and 2004),this paper gave detailed description and analysis on characteristics of land cover in 2004,and land cover change from late-1970s to the end of 1980s and from the end of 1980s to 2004 in the 18 nature reserves in Three River Source Region.The result indicated that by the year 2004 the main land cover type was grassland and the proportion of acreage was 65.68% in the 18 nature reserves of Three River Source Region.The largest proportion of grassland acreage was 83.0% in Yueguzhonglie Nature Reserve,and the smallest was 31.48% in Geladandong Nature Reserve.Arrangements of land cover condition index of 18 nature reserves by 2004 from high to low were Makehe,Duokehe,Jiangxi,Maixiu,Zhongtie-jungong,Baiza,Dongzhong,Tongtianheyan,Nianbaoyuze,Animaqing,Angsai,Zhalinghu-elinghu,Dangqu,Guozongmucha,Xingxinghai,Suojia-qumahe,Yueguzonglie and Geladandong Nature Reserves;Arrangements of land-use change degree from high to low from late-1970s to 2004 wereXingxinghai,Zhalinghuelinghu,Makehe,Duokehe,Nianbaoyuze,Jiangxi,Baizha,Maixiu,Animaqing,Tongtianheyan,Guozongmucha,Zhongtie-jungong,Yueguzonglie,Suojia-qumahe,Dangqu,Geladandong,Angsai and Dongzhong Nature Reserves.Since late-1970s,14 out of 18 nature reserves' land cover conditions turned worse,and the degree from severe to slight were Xingxinghai,Animaqing,Zhalinghu-elinghu,Nianbaoyuze,Duokehe,Baizha,Yueguzonglie,Tongtianheyan,Suojia-qumahe,Guozongmucha,Maixiu,Zhongtie-jungong,Angsai and Dongzhong Nature Reserves.There were 4 nature reserves' land cover conditions got better: Dangqu,Geladandong,Makehe and Jiangxi Nature Reserves.
  • ARTICLES
    Comparison between Color Normalized and HSV Sharpening Methods in Extracting Urban Vegetation Information from ASTER Image
    QIN Peng, CHEN Jianfei
    2009, 11(3): 400-404.
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    The Ministry of Land and Resources has initiated national remote sensing dynamic monitoring project for land use.Through analysis of satellite images of different periods,land use change information can be extracted and analyzed.This research work is mainly based on the operator experience engaged in the project in recent years.Many image fusion methods were developed in recent years accompanied by the development of multi-sensor,multi-temporal and multi-spectral remote sensing technologies.These fusion methods are widely used.However,the traditional image fusion is to increase the image spatial resolution and multi-spectral resolution.This paper is to merge different bands in the same image,attempting to make full use of multi-spectral and higher spatial resolution characteristic of ASTER image,even to mine their potential which can be used in land use and land cover changes.This paper may provide scientific reference for cosmically monitoring land use and land cover change.In order to highlight the edges of images,the line or the areas where a great change has in brightness,an ASTER image was used to extract urban vegetation information of the research area by color normalized and HSV sharpening methods.A comparison was made between the two classified images which were processed by parallelepiped method.Urban green spaces were paid more attention by compared tries.The analysis was made to explore the effects of the two methods based on ASTER images,in order to find a better access to spatial information of urban green spaces by remote images and provide basic data for the assessment in city ecological and the construction of landscape ecology.The result shows that color normalized method has a better performance in the distribution of urban green space,which was good at monitoring dynamically the distribution of urban green space.The structure and the adjacent of urban green spaces were clearly indicated by the fused images.The differences between urban green spaces and other land use types were amplified by the effect of region amplification,different types of edges and manual interpretation,which could highlight the distribution,structure and ecological characteristics of urban green spaces.