Geometry model is the key of GIS software. This paper introduces three geometry models of OGIS, Oracle Spatial and ArcGIS. Their advantages and disadvantages are identified by comparisons among them. The hierarchy of OGIS geometry model is simple, clear and comprehensible. However, some aggressive relationships in OGC model graph were not so abstract because this model is not stable. In addition, Polygon and MultiPolygon in OGC. model is represented only using IineString. The Oracle Spatial geometry is also simple and has powerful extensibility and representability. But, it is more like mathematic geometry model rather than geographic geometry model. The representability of ArcGIS geometry model is most powerful comparing with two others, yet its hierarchy is disorder and dissimilar to OGC geometry. Finally, the authors appeal GIS workers to actively take part in the OGC Specifications for realizing Interoperability Program (IP) as soon as possible.

Considering the environmental features of Tibet, the method of snow information extraction and snow monitoring which is suitable to the large regional scale and global scale based on MODIS data was improved in this paper and then the method and technical route of snow information extraction which is suitable to Tibet based on MODIS data was put forward. It also analysed the dynamic changes of snow information and identified the existing problems and the solution schemes. The research result indicates that this method is more efficient for snow monitoring.

Wetland is a kind of key natureal resources and is an important environment for human survival. Because of natural and anthropogenic disturbances, wetland has been shrinking in large scale. The function of wetland has been lost. All these endangered the sustanable development of human beings. Taken Naoli River Basin as a case study, the spatio-temperal dynamics of the wetlands in the study area and its driving forces from 1954 to 2000 were analyzed. The results show that the wetland area were reduced from 519 917.96 hm² in 1954 to 105 008 hm² in 2000 with the areal percentage reduced from 61.27% to 12.39%. The wetland acreage in 2000 is only 1/4 as much as that in 1954. While arable land acreage increased from 223 173.54 hm² to 597156.25 hm². The acreage percentage increased from 25.31% to 70.45%. And the predominant driving force for wetland shrinkage in Naoli River Basin is the reclamation activities by human beings.

Landscape mosaic structure mainly refers to the distribution of patches, which are different in size and shape in space owing to the interaction of various ecological activities. The study on landscape mosaic structure provides valuable information for rationale management of the environmental resources and has been one of the key study areas in landscape ecology as a whole. This article firstly presents the dynamic change of land-use/land cover landscape in the last 6 years in Widgeon Lake wetland based on RS,GIS and GPS and discusses its environmental effect on wetland. And then based upon which, through selecting indices such as patch size, fractal dimension, fragmentation, diversity and dominance index, etc., it gives a detailed analysis of the change of wetland resources landscape mosaic structure in the last 4 years, supported by RS image with high spatial resolution. Widgeon wetland located in the range of 115°47′-115°54′E and 40°25′-40°30′N covers an area of 10000 hm2. Satellite imageries of different years, Landsat TM in 1996, Landsat ETM in 2002, Indian IRS in 2000 and 1:30 000 infrared color aerial photograph in 2001 were used to analyze the dynamic change of land use/land cover landscape and wetland landscape mosaic structure in this study area. For the images captured approximately in the same season, the change detection error introduced by mere seasonal difference was minimized. Following the interactive interpretation procedure, the distribution map of land use/land cover landscape in 1996 and 2002 and wetland landscape in 1998, 2000 and 2002 were obtained, which were geometrically registered to a common map projection. Software Arc View 3.3, MiragePro5.5 , PCI 8.2 and Excel 2000 were employed in the work. The study shows that the number of wetland resources patches in 2002 decreased by 48.5% compared with that in 1998, the index of the fractal dimension of the whole wetland landscape patches decreased from 1.464 in 1998 to 1.426 in 2002 and the index of fragmentation decreased from 0.9979 to 0.9959. In short, the impact of human activity on the Widgeon Lake wetland during 1998-2002 was not most important because some protective measures had been taken after the nature protected area was built up in 1997. The impact of drought on the wetland was the fundamental factor, especially from 1998 to 2002, but great attention should be paid to the impact of human activity.

The socio-economic information is defined as the database resources which reflect the regional economic development and status quo of society and are collected by government subdivisions in region or some administrative districts. The main contents consist of geography, natural resource information, census information, basic unit information and macro society information. The socio-economic information acts as an important reference to scientific decision-making and administration and serves as the important gists to get cognition of regional condition and to make decisions. It is very difficulty to organize, access and analyze a large volume of socio-economic data during constructing a socio-economic GIS. In the existing socio-economic GIS, the method of direct access database is widely used because of its good access speed. However, some problems appear in some systems such as: (1) some systems are less controllable and less flexible; and (2) unable to adapt to the chenges of structure or content of database. In this paper, the components and characters of socio-economic data are discussed. Also, a new method based on metadata to organize socio-economic data is presented. Finally, to support this method, a case study on socio-economic GIS of Qingshan district, Baotou city is provided.

A comprehensive application technology and method for various geo-scientific data like remote sensing, geo-physics, geology, etc. were discussed in this paper. From the application characteristics of multi-source remote sensing data in uranium resource exploration, the authors made researches on information fusion by taking the full advantage of aero-radioactivity gamma information, the characteristic information in uranium geologic field, and developed three types of fusion images of MR (Multi- spectrum-Radioactivity), MSR(Multispectrum-Synthetic aperture radarsat-Radioactivity), and HSR(Hyper-spectrum-Synthetic aperture radarsat-Radioactivity) based on four kinds of information of multi-spectrum remote sensing, synthetic aperture radar, hyper-spectrum and aero-radioactivity. On the basis of the above researches, the authors further overlapped the interpretation map of the above fusion images with other geo-scientific data like gravity, magnetic, geo-chemical, geological and so on. As a result, an integrated technologic system with characteristics of nuclear industry, based on remote sensing spectrum and airborne radioactive gamma energy spectrum, was established. The system has been used to geological mapping and uranium deposit exploration in vegetable-covered granite area, volcanic rock area and sediment basin. Good application effects were obtained.

Based on the analysis of certain achievements in the geological history, this paper mainly discusses eight issues concerning creative thought in the study of earth science. Those issues include: l)the creative thought is chained by old idea; 2) suspicion and dissatisfaction to the old idea is the starting point of the creative thought; 3) creative thought originates from the creative observation; 4) imagination and deduction is the important parts of the creative thought; 5) systemic analysis to the information is beneficial to the creative thought; 6) the effect of front and clearance in the creative thought; 7) contrast, focus and extension are the general way in the geological research; and 8) inspiration takes an important role in the creative thought.

The article summarizes the study of electronic maps and offers direction of development. It includs three sections. The first one, introduces the status of electronic map production. The electronic maps and atlases produced and published in China consist of three types, that is, reading type, interactive type and network type. The second one is about building system of electronic map. It introduces the model of electronic maps by adopting object-oriented approach; discusses how to establish the designing template of map layer and how to develop software system (EA-world) of electronic maps; and identifies some problems in designing electronic maps. The third one, points out the direction of development of electronic maps. it suggests to strengthen theoretic research in modern cartography in order to guide the production of electronic maps; to carry out study on web-cartography in order to share map information jointly; and to do more works in designing data model in order to improve the quality of electronic maps.

The problem of three-dimensional spatial simulation is discussed in this paper. Firstly, the threedimensional space where any geo-phenomenon is located is discretized in regular hexahedrons which topology and geometry are simple. Secondly, the attribute of every vertex in each hexahedron cell is calculated with the appreciate geo-model. Finally, the marching cube approach is used to process the scalar values of every vertex and the isosurface is tracked. The resulted iso-surface and further processed three dimensional contours are used to express the distribution and state of this geo-phenomenon. The smoke concentration in three-dimensional space pervaded from point sources is simulated with this simulating approach. The result shows that this three-dimensional simulation approach is effective and intuitionistic.

Retrieval and management of mega remote sensing image data need efficient approaches of content-based image retrieval. Now researches of content based remote sensing image retrieval focus on exploring the approaches for extracting low level vision features, such as color, texture, shape and so on. We are short of practical CBIR system. In this paper we present the architecture of RSIQuery system and discuss the data model and data organization. Finally we address some of the preliminary results on content-based remote sensing image retrieval and future work.

The university degree program for Cartography and Geographic Information System (GIS) is one of the three degree programs in geography, but the sphere of influence of GIS is not limited within geography or geosciences. In 2005 there are 114 universities offering bachelor's programs for Cartography and GIS (31 from teachers' universities, 27 from universities, 25 from universities of technology, 8 from agricultural universities, 6 from geological universities, 5 from forestry universities, 3 from universities of transportation studies, 3 from achitectural universities, 2 from universities of posts and communications, 1 from hydrologic university and 1 from economic university), and 16 universities and academies offering doctoral programs for Cartography and GIS (6 from universities, 5 from teachers' universities, 1 from university of ocean studies, 4 from the Chinese Academy of Sciences (CAS)). In 2004 there are 54 universities and academies offering master's programs for Cartography and GIS (18 from teachers' universities, 16 from universities, 3 from universities of technology, 3 from agricultural universities, 3 from geological universities, 1 from forestry university, 1 from university of information studies, 1 from university of ocean studies and 8 from CAS), spreading all over the country except Hainan, Xizang (Tibet), Ningxia and Qinghai, mostly concentrating in Beijing, Jilin, Jiangsu and Hubei in geographical and geo-scientific departments. There are 281 research directions in the master's programs (only 26 for cartography) and 126 research directions in the doctoral programs concentrating in science and technology (only 1 for cartography, 1 for economy and 1 for tourism).

The problems of how to manage the land and resources spatial data are presented based on the analyses of their characteristics. The land and resources spatial data are characterized by multi-sources, multiscales, multi-dimensions, multi-times, etc. The application of spatial database technique is the precondition of integrative management of land and resources spatial data. Multi-sources land and resources spatial data can be managed by converting them to the same format or can be accessed directly. In order to reduce the conversion error, metadata can be used while the land and resources spatial data be converted from one format to another. Multi-scales land and resources spatial data can be managed by metadata driving technique because the content of metadata includes the information of scale and projection. For historical spatial data, the paper gives the method of time sequence storage, when the parcels changed, they would be stored in the historical spatial database. All the changed parcels can be traced to their original state. Only by solving the above problems, can the integrative management of land and resources spatial data be realized.

“数字地球”国际学会2006年5月在北京正式成立,“数字中国”研究院2005年在北京大学揭幕,“数字城市”第二届国际会展和论坛,6月11日又接踵在苏州召开,得天时、地利、人和的优势,预祝大会把握机遇,胜利成功,成为引领“数字城市”浪潮的里程碑。我国城镇化速度空前,在城市规划建设、管理与服务各方面的数字化工程,方兴未艾。实现以信息化推动产业结构性调整,以“数字城市”建设夯实城乡跨越式发展的战略目标,提高城市的凝聚力、辐射力和竞争力;全面协调人流、物流、能流的规模和速率,以城镇带动郊区、农村的可持续发展;对保障“十一五”发展规划的协调、和谐社会建设是至关重要的举措。

To figure out some basic problems in current digital region construction, this paper puts forward the concept of digital region application infrastructure (DRAI), and analyzes the research background, reference model and application supporting platforms for information sharing. DRAI is on the top tier above network infrastructure and spatial data infrastructure. It is composed of a series of information service organizations, management regulations, standards and norms, key technologies and application supporting platforms, and provides fundamental supporting services for various regional information system projects, such as e-government, e-business, digital cities, digital communities, LBS, etc. Information service organization is the main body of DRAI, providing "bridge" for information consumer and information provider. The core parts of DRAI are application service platforms, which provide unified frameworks and solutions for regional information sharing and exchanging. Among the platforms, the metadata management and catalog services platform provides "one-stop" entrance for information registration and query; the information sharing and cooperation platform provides information sharing and exchanging services among distributed databases; the spatial information web services platform realizes the centralized sharing of geospatial information. Finally, the paper summarizes the achievements of Digital Fujian which based on DRAI, and images the requirements and development of Digital Fujian Project in 11th Five-Year Plan period.

This paper considers that there is a gap between mountain altitudinal belts and the traditional GIS, and that a "bridge" should be constructed between them. A "digital engine" is created, which makes it possible to digitize mountain altitudinal belts. Based on the collection of a great amount of data and resource about mountain vertical belts and their standardization in China, this paper makes use of the component AO of ArcGIS and VB programming language to develop a mountain altitudinal belt information system (1.0) for China. This system is object-oriented, and establishes the spatial connection between altitudinal belt spectra and geographical location, allowing the possibility for the digital analysis of vertical belts between multiple regions. The interface of this system is friendly, easy to operate. This information system provides physical geographers and ecologists with a perfect data collection of mountain altitudinal belts and an effective tool for spatial analysis of mountain altitudinal belts. Its successful development means that the study of mountain altitudinal belts has entered a digital era.

The Population Atlas of China is a sound tool which has integrated the fifth census data of China in the forms of maps, documents, digits and graphs to illustrate the actual development level of the population nowadays in China. The digital atlas system, designed for the census data input/output, category, storage, query, statistics, mapping, analysis and management, provides the basic information and modern tool for the decision makers and researchers for analyzing population problems and making the long-term exploration policy. This paper discusses several key matters regarding the population visualization, including its system structure, the main functionality models and the atlas inventory, etc. First of all, a system structure composed of four modules of map maker component, atlas management component, atlas viewer component and census database querying component is summarized, and the key models of the system, such as cartographic symbols model, index tree management of census database model and atlas integration model are analyzed and designed based on the running mechanism and workflow of the system. Secondly, by the consideration of "the fifth census data" and the population problems in China, about 200 maps relating to 10 map categories (environment, population distribution, sex and age, immigration, nationality, family and marriage, birth, education, employment, housing) are created for the atlas, which can visually provide information about the real situations, variation, distribution, and constitution of population in China. Finally the paper discusses several cases of population maps made by variant types of cartographic symbols which are used directly to reflect the regional differences and the variations of population in China.

Xingguo county is one of the areas suffering from most serious soil erosion in the hilly red soil region of southern China. In the recent years, the status has been changing positively by taking different methods to prevent soil and water losses. The main purpose of this paper is to master the trend of soil erosion during this period and soil erosion status in this county. It mainly introduces the dynamic monitoring method based on NDVI in combination with image classification to analyze soil erosion changes in the past 20 years. After rectifying TM data of 1987,1994 and 2000, thresholds are specified considering the assistant information from NDVI different histogram plots. Accordingly, the changes mask image is made available and used in classification. Then, to check the accuracy, classification result is contrasted with field samples. Finally, this paper concludes that the soil eroded area kept decreasing in the past 20 years. For the spatial distribution of soil erosion, the decreased soil eroded area are scattered around central part and some areas of the eastern part of Xingguo; the areas suffering from deteriorated soil erosion were limited, except for some places scattering around the county borders and the southwestern part of Xingguo. At present, the areas related to soil and water loss are mainly distributed in the places with an elevation below 500m and slope gradient less than 20.

Hyperspectal remote sensing acquires sequential object spectral images with high spectral resolution in special spectral ranges, and provides more subtle spectral information. It is propitious to select clear bands for identifying single object spectrum, which made it largely used in object identification. The article used absolute exponent as one of the methods of fuzzy diagnosis to identify and classify hyperspectral images, then evaluated precision of classification result based on pixel level.

Current research on land information systems mainly focuses on particular projects, thus causing a great lack of reusable components in the land management field. This is unfavorable to the development of land information systems. Besides, research on metadata is mainly concentrated on metadata standards, ways of metadata expression, metadata management and metadata contents. Research on and development of metadata applications in land information systems are quite inadequate. This paper introduces metadata technology into the development of components. It adopts metadata to define business rules and drives the running of components through metadata. When business changes, it only needs to change the definition of business rules in the metadata base and use components to meet the needs of business changes. This will improve the reusability of business components, expand the scope of metadata applications and lay a foundation for the rapid development of land information systems.

Two basic dimensions for describing the human social development and human cultural phenomena are space and time. Previous humanities research emphasizes much of the attribution of phenomena itself and time dimension because of the technologic limitation and epistemological difference. Sometimes these research ignored the space dimension or retained the attitude of excluding it. Fortunately, more and more scholars have rethought the importance of spatial coordination system and begun to use spatial thinking in their research. These scholars come from the discipline of history, philosophy, literature, economics, sociology, anthropology, archeology, geography, politics, statistics, etc. This article, based on the instructive thought of space and integrated humanities and social science research, intends to take modern geographic information science and methodology and related space technology as a platform, to tentatively discuss the spatio -temporal characteristics of multi-disciplinary humanity and social science research. Emphases are given particularly to the spatial attribute, space distribution, spatially mutual affection and space evolution rule of the economic and cultural phenomena in human society. In this article, the authors put forward the elementary thought of spatially integrated humanities and social science research which includes basic concept, research object, basic methodology and development direction and wish it can promote the discussion.

In the distributed environment, the existence of the distributed features in the presented object of spatial data, the source of the spatial data and the object of the spatial information service decided that GIS had the distributed feature, too. Meanwhile, the spatial information service has the demand of real time. The active spatial information service is the necessity for overcoming the illogicality between the distributed feature and real time of the spatial information service. Firstly, to resolve this illogicality, this paper advanced the conceptions of active geographic information and active geographic information system. Secondly, it advanced the architecture and active service rules of the active geographic information system by taking node of the distributed GIS as an example. Thirdly, it considered that a node of the active GIS includes a typical GIS, an event driven knowledge base and an event monitor. The realization of the active function depended on the event monitor scouting some event's arise and active service rulers in the event ruler base. Finally, it advanced basic event and its expression, event operation's methods and the expression of complex event, and studied the realization approaches and key technologies of the active geographic information system. The architecture,realization approaches and key technologies had been tried in an application GIS. The experiments indicated that the active geographic information system is efficient for providing real time spatial information service in the distributed environment.

1 北京南北中轴线不是正南正北向 北京南北中轴线(以下简称北京中轴线)不是正南正北,这中轴线不在子午线上。北京中轴线与子午线不重合,而是偏西北北方向。明朝以后,这中轴线南起永定门,北至钟楼,约8km。往北离永定门越远的建筑,离子午线就越远。以通过永定门的子午线为准,钟楼就向西偏离这条子午线近300m了。元、明、清三朝30几位皇帝的宝座都是歪的,歪得不太多,向逆时针方向偏转2度多。

This paper mainly introduces the design and technologies about the basic platform of Geo-Info TUPU System. Based on further study and discussion on the theory of Geo-Info TUPU, and according to the specific requirements of the system, the basic platform of Geo-Info TUPU System is designed and programmed by using presently advanced system designing theory, computer software engineering technology, and other programming technologies. The key technologies of the system such as embedding and editing OLE object in the TUPU table, the connections of the TUPU table and GIS data will be discussed in this thesis.

This article discusses the method of using Wavelet Transform and Mathematics Morphologic Subject to extract the canal of the area objects on the high resolution remote sensing image. As the experiment showed, after the veins partition of the images using the Wavelet Transform, the habitat extraction on the high resolution remote sensing image can be implemented by using the sorts of operators combined by the basic operation of Mathematics Morphologic Subject, choosing the right structure element and the vector tracking, the result of the method can be directly used in the application of GIS.

It is an important task in GIS research to efficiently access and manipulate the spatial data stored in database management systems. The author introduces the spatial data storage methods in database management systems, then puts forward a method accessing and manipulating geometric objects with LibPQ, which is provided by PostgreSQL DBMS. This method allows users to expand user_defined geometric models with inheritance from system geometric model. Moreover, the method can make full use of an expanded user_defined geometric model to process spatial operators. As a kind of open source database management system, PostgreSQL DBMS can provide users with conveniently operated procedures at a price lower than the non-open source database management systems. Users can code inside the database management system to solve some problems which can not be dealt using the non-open source database management systems.

Land resources are essential to human survival. To ascertain the actual situation of land resources and information of land change serves as a basis for overall planning of land use and macroscopic decision making on land resources. In order to raise the efficiency of land change survey, this paper designs a Land Change Survey System on Palm (LCSSP). Based on PDA, this system integrates GPS card, GSM and digital camera, which adopts real time differential process to improve positioning precision. Thus LCSSP becomes a pocket field land change survey system with high precision. Under Windows CE environment, functions of the system, such as land change survey, GPS data process, vector data edit and so on, are developed by using eVC (embedded visual c++ ) program language. LCSSP fundamentally solves some inherent problems including long cycle, low efficiency, and low precision in land change survey.

Supported by GIS, Landsat TM, ETM and CBERS data are the main information sourses. Using combinations of vector data with raster data, multi-sourse data with multi -period data, combination of multi-information extracted metheds, combination of RS data with eco-environment basic maps, indoor processing with outdoor investigation, as well as remote sensing information extration technique, remote sensing image processing and DOM making methed, major cities environmental analysis information system in Northeast China was built. Remote sensing dynamic monitoring and analysis of the city evolution law and trend were conducted to serve for environmental management and decision making.

This article analyses the disadvantage of traditional historical geography as the rapid development of GIS provides an opportunity for historical geography, describes the achievements, existing problems and tendency of the applications of GIS in historical geography and presents several ways for better combining historical geography with GIS.

GIS applications are being developed using the three-tier software architecture traditionally used for general-purpose information systems. Even though this architecture is suitable for GIS applications, the special nature and exclusive characteristics of geographic information pose special functional requirements on the architecture. Based on the research of the three-tier software architecture and the special nature and exclusive characteristics of geographic information, we propose a generic architecture for GIS that provides support for the special nature of geographic information and conforms with the specifications proposed by the ISO/TC 211 and the OGC. Finally, we have tried to apply the architecture that we proposed in the development of a GIS application, and the architecture was proved to be rational and feasible.

Nowadays the evolution of Internet has dramatically boosted the progress of Geographic Information System based on networking technology. Many organizations and companies have developed various application solutions that are expected to satisfy users' needs. This paper analyzes present WEB GIS technologies applied to both server side and client side. While illustrating their advantages and disadvantages, a GIS application model based on SUN's JAVA Web Start(JWS) technology was put forward. For the purpose of demonstrating the effect of this model, a GIS system was developed and built by using GIS data which conform to the County Level Standard Format of Land Use Database. This study presents the whole framework of the system and focuses on the aspects related to JWS. Finally, it concludes that this solution can solve the problem of deployments and system upgrades in the actual environment.