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    XU Xinliang, CAO Mingkui
    . 2006, 8(4): 122-128.
    The spectral information of remote sensing images has integrated and realistic characteristics. It has become an important means of using remote sensing information and GIS technology to estimate forest biomass in global change research area. Firstly,the development of using remote sensing information to estimate forest biomass was summarized in this paper. Then four methods which included the method based on relationship between remote sensing information and biomass, the method based on fusion remote sensing data and process model, the method based on K-Nearest neighbor and the method based on artificial neural network were discussed. Finally the shortcomings of current research and the emphases of future research were given in this paper.
    DING Feng, XU Hanqiu
    . 2006, 8(3): 125-130,135.
    Landsat TM has a thermal infrared band (band 6) which can be used to retrieve land surface temperature (LST). So far, three methods have been proposed to retrieve LST from TM6 data, they are Radiative Transfer Equation (RTE), Mono-window Algorithm and Single-channel Method. Due to the complicated process of computation and the general unavailability of in situ atmospheric profile at the satellite pass (especially for the images in the past), it is quite difficult to put the RTE method into real world application. The advent of the other two new algorithms has made it possible to retrieve the real LST from Landsat TM thermal band and with relatively high accuracy. The mono-window algorithm requires two atmospheric parameters (the total atmospheric transmissivity and the atmospheric water vapor content) while the single-channel algorithm only requires one (the atmospheric water vapor content). The land surface emissivity is the common key parameter of these two algorithms. In this paper, we make a comparison between the LSTs retrieved from the mono-window algorithm and the single-channel algorithm over a study area in Fuzhou city, Fujian, China. The Landsat TM image used in this paper is acquired on June 15, 1989. The research results show that: (1) when compared to each other, the retrieved LSTs from these two algorithms have similar overall temperature distributions, but, the LST retrieved from the mono-window algorithm is about 2.45℃ higher than that from the single-channel algorithm; and (2) when compared to the corresponding pixel brightness temperature, a higher difference value is obtained. For the mono-window algorithm, it is about 2.84℃, and for the single-channel algorithm, about 5.28℃.
    Lu zi, Bai Cuiling
    . 2001, 3(1): 63-66.
    Under the situation of network economy rising, the tour Web Site is one kind of new state of tourist industry development. At present, the tour Web Site brings the shock of revolutionary character to the intrinsic market rampart barrier in China tour market, and the new question is constantly emerged in large numbers. This text, analyses the development state and the tour concept of Web Site, advances the question of tour Web Site, and takes apart the cause, finally put forward the development trend of the tour Web Site in China.
    YANG Qingsheng, LI Xia, LIU Xiaoping
    . 2005, 7(2): 78-81,93.
    According to the studies of the use of Cellular Automata in land use, the emergent change of land use could be simulated by CA while the man-caused, uncertainty land use change could be simulated by Agent. This article simulated both of them by Agent and CA with test data in suburb. The result could reflect the effect of CA affected by Agent. The general CA model simulates the uncertainty of urban land change by stochastic model. This kind of stochastic model lack of the definite explanation in geography. In order to explan the stochastic model in geography, Agent was put into the model. In this article, the Agent was the owner of the land user. The subjective factors of the land owner were considered by Agent. United the CA and Agent, the change of urban land use was simulated with the continous changing and the stochastic changing. Finally, a test was made in the rapid development district-Zhangmutou town in Dongguan of China's Guangdong Province.
    ZONG Xiuying, LIU Gaohuan, QIAO Yuliang, LIN Song
    . 2009, 11(1): 91-97.
    In this paper,the information about wetland landscape features of the Yellow River Delta in 1986, 1996,and 2006 were extracted respectively based on TM images and by support of Remote Sensing(RS)and Geographic Information System(GIS)techniques.By analyzing the information,we investigate the spatial and temporal changes of wetland landscape and explore the driving forces for wetland landscape pattern change in the Yellow River Delta within the past 20 years.Our results show that:(1)the area of man-constructed wetland demonstrated a sharp increase,whereas the proportion of natural wetland decreased accordingly.As an important part of the natural wetland,the tidal flat and Chinese tamarisk shrub wetlands in the Yellow River Delta has significantly shrank in coverage and degraded during the past two decades.(2)Since 1990s,some of the important landscape indices such as the number of patches,Shannon's diversity index,and Shannon's evenness index have increased.This indicates that the fragmentation degree of wetland landscape in the Yellow River Delta intensified, the type of landscape was much diversified,and each type is distributed uniformly in the wetland landscape and no dominant wetland landscape types can be recognized.(3)Landscape style transfer occurred between wetland and wetland,wetland and non-wetland.During the interval from 1986 to 2006 A.D,about 18.1%Reed meadow had been transferred to farmland,26.6%Seablite meadow transferred to salt pan and 11.9%Reed swamp transferred to Reed meadow.(4)The driving forces for wetland landscape pattern change analyses were conducted, and the result implies that both natural factors and anthropogenic factors have played important role in altering the pattern.The former includes decrease of discharge and sediment,self succession,while the latter mainly consists farmland reclamation,exploitation of tidal flat and oilfield development and construction.
    WU Xuewen, YAN Luming
    . 2007, 9(3): 104-108.
    This article discusses about the thereunder of choosing the optimum semivariogram models and setting the key parameters based on ARCGIS and GS+software from characteristics and laws of data through understanding the ordinary Kriging interpolation theory, and carries through an in-depth exploratory spatial data analysis taking the spatial interpolation to January average temperature of Fujian province as an example, using the obtained parameters and semivariogram models to simulate the spatial distribution of January average temperature of Fujian province. The aticle offers a clear way for reasonable spatial interpolation.
    SUN Zhan-Li
    . 1999, 1(2): 32-37.
    The geographic phenomena, including global change, urban growth, land-use change etc. have been recognized as complex system. Considering the weakness of the traditional model based on the Newton mechanical model and differential equation, a new approach of applying the nonlinear methods, particularly cellular automata, has become the frontier field of geographical research. Here we bring forth a theory related to geographical model based on cellular automata (GeoCA) and try to simulate the complex geographical behavior dynamically. The advantages and the framework of the GeoCA model are described. Lastly, the growth of Ann Arbor, a city of Michigan in USA, which is witnessing dramatical growth recently, is simulated and forecasted using GeoCA model integrated with geographical information system.
    WANG Tianbao, WANG Erqi, LU Hao, HUANG Yuefeng
    . 2010, 12(1): 69-75.
    The WebGIS development represents a natural answer to the growing requests for dissemination and use of geographical information data.WebGIS originates from a combination of web technology and Geographic Information System.The new technology,RIA(Rich Internet Application),is more frequently used to enrich WebGIS in meeting the demand of high interactivity and rich expression in some extent.There were papers introducing the solution of RIA applied in WebGIS such as Flex,but they mainly discussed the architecture,the function model and so on.Base on the research of Silverlight,the combination between Silverlight and WebGIS is presented in this paper.Especially,the authors discussed how to represent geographic information in multi-scale by simulating and improving DeepZoom,which enables smooth loading and panning by serving up multi-resolution images and using spring animation.And then we integrated vector and raster geographical data by making use of XAML(eXtensible Application Markup Language).It would be much more appealing if taking advantage of animation.The algorithm for displaying huge amount of data was also designed,and it improved the performance efficiently.In addition,the key issue of geospatial web services aggregation and web cache was also mentioned.Finally,to evaluate and present results obtained by this work,this paper includes case studies concerning implementation of the idea.The authors believe that WebGIS based upon Silverlight will play a great role in representing geographic information and aggregating geospatial web services in future,and also,it is more effective.
    LIU Xuhua, WANG Jinfeng
    . 2002, 4(2): 38-44.
    The study of regional spatial weight matrix is of very importance and indispensability in the research of regional spatio temporal process in spatial econometics.Nowadays,when dealing with the regional data, we turn our attentions from pure information storing or staticstical analysis to exploring their growing and developing law by spatio temporal dynamics models. In time dimension, they have their own movement law, but in space the effects from their adjacent regions, that is, spatial dependence, can't be disregarded ,either. And this spatial dependence is expressed by the spatial weight matrix in the spatio temporal process model. Thus constructing the regional spatial weight matrix is one of the key steps of creating regional spatial dynamics equations. In this paper we have reviewed a series of specification forms of the spatial weight matrix, such as binary contiguity matrix, distance weight matrix, a combination of distance and perimeter weight matrix, a combination of distance and area weight matrix, etc. Therefore spatial researchers are at a loss when facing the weight matrix choosing problem and resort to the simplest binary contiguity matrix. But the simple choice of spatial contiguity matrix is very disputable. Hence, in practical application how to choose the form of spatial weight matrix calls for further studies. Although the use of binary contiguity matrix in constructing a sptial process model is dubitable, its simpleness helps the analyst to construct the sptial process model and analyse the data easily at first stage. As for a map of reams of analysis regions, it's fussy and likely to make mistakes to construct a binary contiguity matrix manually. In the paper we come up with the detailed algorithm by GIS software automatically to generate the binary contiguity matrix, which has been validated to be feasible and robust.
    LIAO Ke
    . 2002, 4(1): 14-20.
    Tu" in Chinese words, means maps representing spatial information in graphics , also including images, illustrates and other graphic forms of representing spa tial informatic;"Pu"is a system built according to thing's characteristics or time series. Geo Informatic Tupu has two characteristics with graphics and pedigree. Formed from a great deal of geo information in digit through graphic thinking and abstract generalization, Geo Informatic Tupu is a means and method of using computer multi dimensional and dynamic visualization technology to display and reveal the spatial configuration and spatial temporal change rule of earth system and its elements and phenomena. Five parts are discussed in this paper, they are: 1. the basic concept of Tupu; 2. the discussion of Geo Informatic Tu pu; 3. the basic process and steps of building Geo Informatic Tupu; 4.the example of Geo Informatic Tupu complex Informatic Tupu of natural landscape in China. 5. the meanings of and prospects for Geo Informatic Tupu.
    SONG Yachao, LV Guonian, ZHANG Hong
    . 2004, 6(1): 44-48.
    Internet GIS is one of the most important developing directions of GIS,to build a practical internet GIS system, we must resolve the key technology of multi-source spatial data integration in the internet environ-ment,and spatial meta-data services in the internet environment. Web Service is a new technology in distributed computing domain,and an ideal model to implement inter-operation of different systems. We first made researches on the structure of internet GIS based on Web Service by comparing different computing models and different internet GIS software system structures,and provided a solution to Internet GIS application integration based on standard protocols such as XML, SOAP. Then,we studied the inter-operation of multi-source spatial data in internet environment, compared different multi-source spatial data integration solutions such as spatial data conversation, spatial data directing reading,and provided a new idea in multi-source spatial data integrations based on Web Service. In order to discover spatial data quickly in internet environment,we need a spatial meta-data system,and set up the spatial meta-data service system based on Web Services. The result indicated that spatial meta-data service system should be an essential part in internet GIS system structure. Finally, we introduced a practical example of internet GIS application based on Web Service, Nanjing "Digital House Property" internet GIS system. It is a mixture structure of GIS system,which was built in B/S part using Web Service technology and effective result was gained.
    CHANG Jun, LIU Gaohuan, LIU Qingsheng
    . 2004, 6(1): 94-98.
    The Yellow River is well-known for its highest sediment contents of all rivers in the world. Due to the huge sediment to the coast, the Yellow River Delta is in a state of continuous dynamic change. The most recent shift occurred in 1976, and a new sub-delta is being created since then. This paper describes the method and technology for monitoring the coastline change of the Yellow River Delta using remote sensing. The multi-temporal Landsat and other satellite images were used as the monitoring data source. The images were registered to the high precision GIS database, and they were matched each other and matched with the database. All the images have the same coordinate system. A mean high water (MHW) model was developed for extracting coastlines from remote sensing images. 20 coastlines were extracted from different years. The result shows that a new territory of 330km2 was formed in the present estuary area from 1976 to 2000. At the same time, a territory of 137km2 was eroded in the Diaokou estuary area to the north of the Yellow River Delta. In conclusion, it is the substantial foundation for the water and sedimentation of the Yellow River to shape the delta. That is, it is the essential factor leading to coastline evolution.
    Wan Hongtao, Wan Qing, Zhou Chenghu
    . 2000, 2(4): 46-50.
    The hydrological model,which is a technology developed since 1960s,is a kind of mathematical methods for simulating the hydrological process in the watershed.The the simulation of hydrological process can be divided into two sub-hydrological process,one is the runoff generation simulation and the other is the routing of flow.In the lumped hydrological model the hydrological variable and parameter are assumed as uniform in the whole basin. Due to the Geography Information System technology the distributed hydrological model,which can dea with variety of hydrological variable and hydrological parameter,had got more attention and development. In addition the spatial information,needed by the distributed hydrological model,can be got more easily because of the development of the Remote Sensing technology.
    CHEN Shun-Qing
    . 1999, 1(1): 12-18.
    This paper approaches the topic in 4 steps. The first study concerns the forces of urban growth and the interaction theory of centripetal force, centrifugal force, and friction force. Supported by the new institutional economics, the centripetal force, centrifugal force , and friction force have had a solid fundament in microeconomics. The interaction of the three forces which impel urban growth has been demonstrated through the evolution of labor division, the firm clustering and industrial syntheses forming, and incubator process.The second one focuses on the theory of urban growth. The three stages of urban growth consist of the clustering stage, which is mainly driven by centripetal force, the suburbanization stage driven by centrifugal force, and the networking stage by the interaction of the three forces. According to the three stages of urban growth, urban structure and urban form of the Western developed countries in macroscale (interurban geography) and microscale (intraurban geography) dimensions are discussed. Comprehensive analyses show that the three stages of urban growth and the corresponding changes of urban form are the commonness of every country in the course of market economy.The third one discusses the theory of urban land value and value increment. In this study, the land value is considered a summation of social use value, economic value, and ecology value. The land value increment is classified into invested increment and public increment. Public increment, especially when it is induced by land use externalities, is the bottleneck of increment analysis. The transaction cost economics is introduced to analyze the externalities of urban land use. The fourth one tries to develop a comprehensive theoretic framework of urban growth and, land value increment. Starting with the classical model of urban growth and land value, a typical mode of land value increment of different stages of urban growth is explored. Finally, a six-phase urban growth and land value increment theory is deduced from the above studies.
    CHENG Changxiu, ZHOU Chenghu, LU Feng
    . 2002, 4(1): 86-90.
    This paper reviews the development history of spatial data model, introduces the data model of geodatabase, and explicates the objectClass, feature class, feature dataset, relationship class, domains and rules in the model. Based on the understanding to Geodatabase, the paper discusses the advantages and disadvantages of Geodatabase. In order to make the object oriented spatial model better, this paper gives some advice about restriction rules of compound objects, spatial temporal expression, breakthrough layers, etc.
    ZHANG Hong, FENG Jiangfan, LV Guonian, TENG Xuewei
    . 2007, 9(2): 37-42.
    Geographical Information Systems(GIS) are characterised by the ability to integrate geospatial data from a wide variety of sources.World Wide Web Geographical Information System(WebGIS) is the combination of Internet/Web technologies and Geographical Information System,it makes the Web publishing and sharing of geospatial information in the whole world possible and has exerted great influence on the national economic development and our everyday life.In the application of WebGIS,how to transfer efficiently the geospatial information,such as the user's spatial query submits and the result data from GIS database,through the network is a key factor to determine the capability of the system.This paper firstly analyses the problem existed in WebGIS,and then introduces the Rich Internet Applications,in short RIA,which is a brand-new Web application solution.Considering the trait of RIA,the thought for constructing WebGIS based on RIA is presented,and three key techniques adopted in RIA based WebGIS are summarized and analyzed.After that,this paper describes the framework of WebGIS based on RIA,consisting of five layers:client layer,presentation layer,business layer,integration layer and resource layer.In the design,the realization of client,server and protocol are discussed in detail.Finally,the thought given in this paper is proved feasible and effective with an experimental system,in addition,some future work in WebGIS based on RIA,such as security,interoperability are indicated and simply explored.The authors believe that with more research on WebGIS based on RIA,RIA will play greater role in publishing geospatial information,furthermore,the geospatial information web sharing will become easier.
    LUO Zhiyong, LIU Xiangnan
    . 2004, 6(4): 105-109.
    In recent years, how to use spatial database to store and manage spatial data has become a hot topic in the field of GIS. However, the study on spatial database structure design has been ignored relatively. Most investigations just emphasize the realization of special application of softwares which are relative to spatial database. Accordingly the author carried out a comprehensive and in depth discussion about the related questions in this article, including the difference between spatial database and general database, the key technology and frequently asked questions while building spatial database. In this article many important thoughts and rules for the different design stages are put forward and the importance of standardized design is also emphasized. In the structure realization stage, a detailed treatise about how to scheme out a perfect Geodatabase with CASE tools has been given. The facts proved the importance of UML and CASE tools in the design of spatial database.
    HU Peng, WU Yanlan, HU Hai
    . 2003, 5(3): 64-70.
    As an important information source, DEMs (Digital Elevation Models) have found applications in a wide variety of areas, such as view shed analysis, watershed partition, derivation of geomorphic features, etc Assessing the accuracy and quality of DEMs scientifically will assure the production, construction and right applications of DEMs. Except factors of data sources, instruments and man made, the major error of DEM roots in interpolation arithmetics. So,the assessment of the accuracy of DEMs is a kind of error analysis aiming at the interpolation accuracy mainly There exist two methods that have the specific theoretical context and accuracy analysis among numerous methods to generate DEMs. One method is TIN (Triangulated Irregular Network) interpolation based on discrete ground elevation points, the other is bilinear interpolation used for grid ground elevation points obtained by photogrammetry. This paper gives error models of the above two interpolation methods. The two error models explain some problems that can't be interpreted using RMSE. Nowadays, the two methods to generate DEMs have a wide range of application in practical DEMs productions. Both have own advantages and application fields At present, there are major methods to assess the accuracy of DEMs: test, transfer function, covariance and contour maps produced from DEMs. For test method, the sampling check points lack rigorous theoretical basis. While both methods of transfer function and covariance have difficulty to assess the accuracy of the whole DEM and render the factual distribution of errors,they also can’t estimate the status of the DEM coinciding with the factual topography. In the situation of lacking a valid theoretical accuracy assessment about DEMs presently, contour maps produced from DEMs serve as a natural method to evaluate the quality of DEMs. In fact, as long as the method applied to DEMs interpolation is right, the maximal difference of the original topographic map and the map generated from the corresponding DEM will be less than a half of the numerical value of contour-interval. And the overlay map of the original topographic map and the map obtained from the DEM is just an elaborate render of the whole DEMs error In a word, assessing the accuracy of DEMs rightly is of momentous practical significance and theoretical value. We must adopt truncation error to assess the accuracy of DEM abandoning RMSE. Comparison of the original topographic map with the map generated from the DEM is the most effective method to check the quality of DEMs.
    LU Zi, GUO Laixi, BAI Cuiling
    . 2004, 6(1): 67-71.
    The paper focuses on the impacts of IT in regional economic behavior, particularly explores the impacts of web technology, as a new type of IT, on tourism industry. The main contributions in tourism website development include: putting forward an evaluation system for tourism website, and according to the framework, Hebei province's tourism websites were evaluated from content setup, technology organization and service quality. At the same time, it established an online service functionality evolution framework and used the framework to orientate tourism website development in China, and identified current tourism website users and user satisfaction at online tourism service throughout the country. Academically, the study extends the research of communication geography.
    GONG Minxia, LU Guonian, ZHANG Shuliang, CHENG Suozhong
    . 2002, 4(1): 91-97.
    This paper makes an analysis on model base and the integration method of GIS and application models based on model base. After making a comparison on the integration method of model base with other old integration methods, the authors bring up a new scheme on integration of GIS and application models: spatial decision support model base system driven by intelligence. The new system is supported by data base, model base and knowledge base technique. The paper makes an analysis from how to build knowledge base serving model base, the decision flowsupported by intelligent model base and so on. It also gives an instance of basin environment pollution management based on intelligent model base system, which validates the feasibility and validity of the new model integration method.
    CHENG Weiming
    . 2002, 4(2): 61-65.
    Based on lots of materials and former research, this paper discusses classification and mapping course of landscape ecology inner and outside at present, typing of landscape ecology needs to link regional actuality, and classifies grade by grade; states familiar mapping course from image of remote sensing, takes the northern slope of Tianshan Mountains as an example, using ETM image, gets landscape types map of LUCC.
    LIU Jiyuan, ZHUANG Dafang, ZHANG Zengxiang, GAO Zhiqiang, DENG Xiangzheng
    . 2002, 4(3): 3-7.
    In the mid-1990s, we established the national operative dynamic information systems on natural resources and environment. In the process of establishment of the land-use database, 520 scenes of remotely sensed images of Landsat Thematic Mapper (TM) were interpreted at scale of 1∶100 000 under overall digital software environment after being geo-referenced and ortho-rectified. The vector map of land-use in China at the scale of 1∶100 000 was recently converted into a 1-km raster database that captures all of the high-resolution land-use information by calculating area percentage for each kind of land use category within every cell. Being designed as the operative dynamic information serving systems, monitoring the change in land-use/land-cover at national level was executed. We have completed the updating of LUCC database by comparing the TM data in the mid-1990s with new data sources received during 1999~2000 and 1989~1990. The LUCC database has supported greatly the national LUCC research program in China and some relative studies are incompletely reviewed in this paper.
    PAN Yuchun, ZHONG Ershun, ZHAO Chunjiang
    . 2004, 6(1): 36-40.
    Spatial database update is a matter of urgency, which will become the "bottleneck" to GIS application instead of spatial data production, hence it has become a focus in GIS research fields. The aim of this study is to provide reference to help solving the problem of spatial information update. In this paper, ways of land use spatial data update and the methods to achieve update are studied. Overlay analysis, spatial relationship between spatial entities and smart snap based on spatial analysis are the technical bases for spatial data update. Complete update and partial update are two main ways to spatial data update, and they have differences in many aspects, such as existing way of data sources for update, operational object, technologies for update and key technologies.
    FAN Zemeng, YUE Tianxiang, CHEN Chuanfa, SUN Xiaofang
    How to attain the high-resolution spatial climate grid data by high accuracy spatial interpolation method according to the climate observed data scattered over China, which can satisfied with the demands of ecological process, structure and landscape simulation model, and ecosystem integrated assessment model, is the focus issue in the field of ecological modeling. To address the above issue, the property feature data from 752 weather stations during the period from 1964 to 2007 are transferred into spatial feature data in terms of coordinate information supplied by every meteorological station meteorological data. SRTM DEM of China on a spatial resolution of 90m×90m is transferred into DEM on a spatial resolution of 1km×1km using the resampling method. The DEM is used as auxiliary data to develop the statistical transfer functions of mean annual temperature and precipitation. The spatial distribution trend model of mean annual temperature and mean precipitation are respectively developed by spatial statistical analysis method combined with the factors of elevation, longitude, latitude, aspect, and slope, which are integrated into the High Accuracy Surface Modeling (HASM) method. Spatial change trends of mean annual temperature and mean annual precipitation in China in the four periods of time of C1 (1964-1974), C2 (1975-1985), C3 (1986-1996) and C4 (1997-2007) are analyzed in terms of results from running these models. The simulation results indicate: (1) Mean annual temperature has shown an accelerating increase trend with the rate of speed of 0.28℃ per ten years since 1964, respectively rose 0.1631℃ during the period from C1 to C2, 0.3835℃ from C2 to C3 and 0.7007℃ from C3 to C4. (2) Mean annual precipitation increased by 4.7069mm during the period from C1 to C2, decreased by 2.1335mm from C2 to C3 and continuously decreased by 2.3735mm from C3 to C4. Furthermore, the conclusion can be got that the continuous and high-resolution climate data can be quickly attained from the observed climate data on scattered distribution by the HASM method integrated with the factors of elevation, longitude, latitude, aspect, and slope, and are available used to the parameters of spatially explicit multi-scale ecosystem model.
    PAN Zhiqiang, LIU Gaohuan
    . 2003, 5(3): 91-96.
    Evapotranspiration is an important parameter for water resource management Compared to the traditional ET computation methods, the ET computation method based on Remote Sensing has the characteristics of quickness, precision, large scale and visualization mapping SEBAL (Surface Energy Balance Algorithms for Land) is a model which is used to compute evapotranspiration in large scale region based on Remote Sensing images which have the visible, near infrared and infrared bands SEBAL model is based on surface energy balance equation which includes net radiance flux, soil heat flux and sensible heat flux and latent heat flux All these three heat fluxes are computed in sequence, then the latent heat flux which provides energy for evapotranspiration can be computed, finally instantaneous ET and daily ET can be obtained In this paper SEBAL model was used to compute the evapotranspiration for the Yellow River Delta where water resource is facing an urgent situation, in the end the evapotranspiration characteristics of Yellow River Delta are analyzed This study is helpful for better management of water resource of Yellow River Delta.
    CHEN Songlin, LIU Qiang, YU Shan, LIN Zhilei
    . 2002, 4(1): 61-65.
    This paper study on the method of the evaluation of land resource suitability supported by GIS, including selection of evaluation object, determination of classification system of the evaluation, selection of the evaluation factors, determination of target gradation and its fraction value (index) and weighed average value to the evaluation factors, and so on. Based on the evaluation of land resource suitability In Jianan district of Fuzhou, some suggestions on the rational exploitation and utilization of land resource are put forward.
    NIU Baoru, LIU Junrong, WANG Zhengwei
    . 2005, 7(1): 84-86,97-131.
    The paper analyzes three plans on extraction of vegetation cover rate using remote sensing, i.e., experience model plan,vegetation index plan and mix-pix analytical plan and identifies their force, precision and existing problems in actual application. It points out what affects the wide application of precision of vegetation index transform plan abroad is the choose of the maximum NDVI - complete vegetation cover.Based upon this it introduces an improved model of vegetation index transform plan using the maximum NDVI value of the high resolution satellite image as the homogenous pixel's NDVI value to replace the NDVI value of the middle resolution satellite image, set up vegetation cover extraction model so as to develop a method for obtaining large scale vegetation cover with the aid of middle resolution satellite image. Practice proves this method is simple and practical, suitable for large scale macroscopic monitoring by applying middle resolution satellite image.
    MAO Xiancheng, PENG Huarong
    . 2005, 7(1): 76-79,83.
    The handling of spatial data is a key issue of Geographic Information System (GIS). The spatial data can be analyzed and applied when stored and operated in GIS. So, it is important for GIS to store and manage spatial data. At first, this paper introduces the present research status, then analyses ESRI's Spatial Database Engine (SDE) and MapInfo's SpatialWare. It is concluded that the development direction that spatial data and attribute data are managed under Database Manage System (DBMS) is a necessary trend for unified storage and management. Then, depended on the practical technology, the paper discusses storage models of spatial data, and points out a good storage model is Relational Database Manage System (RDBMS) or Oriented Relational Database Manage System (ORDBMS). So, a data model of spatial graphical data storage in RDBMS is presented in this paper. Finally, in light of this model, the paper analyses a relational spatial-data structure based on SQL Server.
    ZHANG Mingbo, SHEN Paiwei, LU Feng, CHENG Changxiu
    . 2004, 6(4): 80-84.
    Integrated storing and accessing geographical features related information is one of the most important technologies for GIS application developments. It has been a consensus of opinion in the GIS society that storing and managing mass spatial data with current business relational database management systems under the support of extended relational models is an efficient and effective technology for developing mass data and network oriented spatial database management systems. In this paper, the authors analyzed and discussed some typical spatial database management platforms including ArcSDE, Oracle Spatial, Informix Spatial DataBlade, DB2 Spatial Extender and MySQL Spatial Extensions from the view of storing models, process management schema, spatial querying and indexing, and data cache approaches. It is argued that current business spatial data engines or extension technologies still deserve much more research and improvements, especially for topology representation within relational database management systems and application schema, adaptive spatial indexing and optimization methods, and user defined complex object representation, sharing and inter-operability.
    GUO Huancheng, SUN Yihui, REN Guozhu, LV Mingwei
    . 2008, 10(4): 453-461.
    As the capital of China,Beijing is one of the first groups of cities that developed agritourism and rural tourism in our country.With rich history and culture,Beijing also has pleasant climate and colorful agricultural resources.All these provide excellent conditions for the development of leisure agriculture and rural tourism.According to statistics,until the end of 2007,there were 1302 agritourism parks in Beijing,generating 1.31 billion yuan income.More than 13570 families and 40000 people are involved in rural tourism industry.More than 26 144 000 tourists have enjoyed their services and products.Now,three types of leisure agriculture and rural tourism have developed in Beijing:agriculture leisure,folk culture leisure and Leisure resort widely distributed in Beijing's suburbs.The present development layout of Beijing's leisure agriculture and rural tourism takes on a three-circled structure and forms ten development bases.To meet the requirements of leisure agriculture industry,Beijing is launching five new tourist routes special for rural tourism products,which provide a good opportunity for leisure agriculture and rural tourism development.Based on the research on development conditions,present situations and characteristics,development layout and tourist routes organizations;this paper gives a comprehensive analysis of the development of Beijing's leisure agriculture and rural tourism.It also puts forward some suggestions for its sustainable development:rational distribution;enhanced management;increased investment;intensive training;and effective legal protection.