Raster spatial database engine(RasSDE) is a key technique to achieve distributed query and efficient management of massive rater data. An object-oriented raster spatial data organizing model is proposed. A distributed four-tired architecture of RasSDE is designed. Database services,application interface and appli-cation services are analyzed. Core component framework and its object classes of RasSDE are discussed. MAMS V2.0 system based on RasSDE is given. The main aims of the system are to realize the object-oriented raster spatial data organization,integrative massive spatial data management and distributed spatial data computing. The comparison experiments of disk read-write and network transmission synthesized capabilities between RasSDE and ArcSDE are performed. The results show that raster data network transmission efficiency of RasSDE is higher than that of ArcSDE,and RasSDE can satisfy the demand of massive raster spatial data transfers.

As the core of managing spatial data in GIS, the field of spatial analysis in physical geography becomes broader and broader. In the geospatial data processing, GIS spatial analysis is the theoretic and technical basis for analyzing, simulating, predicting and regulating the spatial processes. The spatio-temporal data models for spatial analysis are the impotent means to analyse a series of regional or global geographical problems in geoscience, which bring new challenges and opportunities to physical geography. Viewing from the definition and application of spatial analysis, the author studies and explains definition and development trend of spatial analysis, and draws the following conclusion:Firstly, modern geography needs more and more spatial analysis technology while the field of spatial analysis in physical geography becomes broader. Secondly, the spatial analysis becomes a major technologic approach in the research of physical geography. The method of processing geospatial data must integrate with spatio-temporal model, data mining, visualization, and the relevance of factor in multidimensional information space. In the near future, the combination of spatial analysis technology and integrative research of physical geography not only widens the field of spatial analysis technology but also drives rapidly the development of Geo-information Sciences. In a word, the combination of spatial analysis and integrative research of physical geography has already been one of the most important trends in the development of both modern physical geography and geo-spatial information sciences.

The algorithm of optimum route analysis based on raster data model,which considers different influencing factors as driving time and expenses,confirms the optimum route through calculating the accumulative cost value minimumly.Taking road-network in the Pearl River Delta as an example,this paper introduces the simulation technologies of road shape and driving speed, and the analysis of the shortest driving time and expenses.Finally the shortest driving paths between the major cities in the Pearl River Delta are calculated.

With the gradual deterioration of the eco-environment,formation and perfection of "digital earth" strategy,digital ecology has gradually aroused the attention of relevant scholars at home and abroad.As an application system in the ecological professional field,digital ecology has not been ripened and perfected in terms of basic theories and frameworks yet.This paper holds that digital ecosystem is made up of the general information platform,the professional basic platform and the comprehensive decision platform,and the above three major information modules form the overall frameworks and the systems of digital ecology.At the same time,the basic frameworks and structures of the three major information modules have been explained in detail.Finally,the paper takes flood disaster system and remote sensing monitoring system of eco-environment as examples to expound the application of digital ecology.It points out that building the multi-level systems engineering of digital ecology needs supports of corresponding technologies,restrictions of the standard criterions,government's macro-management,guarantee of the policies and regulations,participants of experts with comprehensive knowledge.

Wetlands provide a range of environmental and socio-economic benefits,which range from their ability to store floodwater,improve water quality,provide habitats for wildlife and to support biodiversity and aesthetic values.The loss of wetlands,which was caused as a result of urbanization sprawl,and land cover change,has gained considerable attention now.The utilization of satellite remote sensing and GIS technology for wetland information extracting and dynamic monitoring has proven to be a useful application.The objective of this study was to find more efficient way to extract wetland information from remote sensing data.Decision tree models were designed and carried out for extracting wetland dynamic change information from TM/ETM+ image,which acquired on April 9,1988 and March 4,2001 respectively.And the results show that the precision is pretty high and satisfactory.

In the field of power GIS domain,there are some characteristics,such as high real time response and reliability,complex electric power network and large volume data. According to these characteristics,we build a network model and make a mapping between the real electric power network and geometric & logical network,which highly simplifies the complexity of data query & maintenance and network analysis. Furthermore,we apply this model into power GIS and implement the mapping between geographic graph and logical graph. By introducing complex edge and complex cross point,we resolve the problem of "crash point" and "crash edge". Because our model supports real time reconstruction of topological power network,it makes the network analysis and query maintenance easier. On the basis of the above analyses,we successfully implement this network model in the power GIS domain.

SWAT (Soil and Water Assessment Tool) is a physically based, distributed non-point pollution model system developed by USDA. It can be used to model multiple geographic processes as well as predict the impacts of different management practices on water, sediment, agricultural chemical yields and pesticide fate in a river basin scale. Due to complex structure and too many components, SWAT model is difficult to modify or to be integratively applied with other models. In this paper, the inner running structure of SWAT was discussed based on the analysis of its components, and the core configuration file using for running model was presented with an example.

Digital Earth now is becoming one of the leading technologies in the Internet GIS research and development.In this area,there are commonly two of the key techniques that a Digital Earth software system′s development process should deal with: one is the great amount of spatial data should be properly organized and stored in spatial databases,and the other is the spatial data should be effectively transported on networks such as Internet and/or Intranet.By the implementation of the Digital South China Sea(DSCS) system,this paper discusses several technical methods that can mainly be used for independently design and development of geo-relational database models and transport protocols on account of concerning the nation's information security issues.The resulting modeling solutions for the DSCS are: Firstly,the object-oriented ORM source model is adopted as a new spatial database data conceptual modeling technique.Secondly,the logical model of the spatial database is built by using the IDEF1X model which is more effective in semantic description.And thirdly,the storage model of the spatial database is based on relational database.Besides,the spatial data transport protocol is designed and implemented using the asynchronous unblock socket method together with the multithreading method in C++ programming,and directly on the basis of the TCP/IP protocol.It is proved by testing the DSCS system on networks that these technologies can make the spatial data efficiently and safely exchange between the three-dimensional rendering client system and the spatial data server system that are a necessity for a Digital Earth.The DSCS also supports most of the functions and manipulations which are similar to the Google Earth,e.g.the database storage of spatial data such as points,curves,polygons and images,data streaming and progressive transportation etc.For the fully possessed proprietary intellectual property right to the database model and the transport protocol,the DSCS can improve the development of China's national Digital Earth system and provide more safety guarantee to the important spatial data of the nation when transporting on the Internet.

In this paper, discontinuous stratum is partitioned into tetrahedrons for better representation and analysis of its inner structure. In the process, topological relationships of the spatial primitive data objects, such as nodes, edges, faces and voxels, are carefully designed and decomposed topologically at different levels. An object-oriented object manager is proposed to manage these spatial data. Considering the object manager, appropriate data structure and efficient indexing are adopted to organize the spatial objects so as to accelerate the process of confirming the uniqueness of any topological object in the storage list. With the object manager, both the generation of different levels of topological objects and the spatial inquiry efficiency are greatly improved. A case study proved that this method is efficient in real stratum segmentation.

Realization of a number of national and international programs dealing with spatial data infrastructures-SDI,such as the Digital Earth,has already made it possible to compile a uniform digital base and a universal toolkit for the integrated description of territories.SDI(spatial data infrastructures) may form a reliable basis of integrated digital territory models(IDTM) that are necessary for the realization of any models of sustainable development for these territories.The attempt of realizing this idea is carried out within the framework of information system "Sustainable development of Russia" developed in the Moscow State University.We are developing a test unit for processing a wide range of organic waste products as a part of GIS.

Slope is one of the crucial terrain variables in spatial analysis and land use planning.DEM based slope extracting method has been widely used in practice.However,the slope data uncertainty which is very important to the applications has always been neglected.This paper focuses on how resolution affects the uncertainty of the slope extracted from DEMs in Shaanxi Province.Taking 1∶50 000 DEM with a resolution of 25m with a total of 671 sheets of Shaanxi as source data.The research shows that the average slope reduction along with the DEM resolution assumes a conic trend,but when the DEM resolution reduces to a certain degree,the average slope would tend to be stable;and from the result of the comparison of the slopes derived from different resolutions,we can see that the slope uncertainty presents an obvious spatial constitutive distribution.

The evolution and the different study interests of Mobile GIS, Location Based Service and Geographic Information Mobile Service were introduced. Based on the comparison of the three main wireless internet access methods in mobile communication, WAP, i-mode and J2ME, the choices of wireless access implementation methods were proposed. WAP is the best way for future public Mobile Geographic Information Service and J2ME is more suitable for offering the personal assistant spatial-info service, like LBS for car-owners. The future research should be more focus on the key technologies about the new integration frameworks, cooperation and interoperation, nature language expression and more efficient geo-computation, in order to offering more powerful 4A public Mobile Geographic Information Service.

As a 3D-visual geospatial information platform based on geographic research and geographic analysis,the virtual geographic environment needs to allow sharing geospatial information resources which have different storage locations and diverse data formats. This paper studies organization and management of the geospatial information and the metadata of the virtual geographical environment. It defines the object-oriented idea to define the simple geospatial information object entity,and expresses the complex spatial information object entity according to the iterative combination. The XML description solution,which describes the geospatial information object and metadata information,is designed. A sharing platform which combines the centralized management of geospatial information object with distributed services of geospatial information is built. Web services of browsing,analyzing,and operating the geospatial information are afforded,which allow for multiple users located in different geographical areas to share distributed geo-information resources,and to implement coordinated work and decision making.

With the adoption of opening up and reform policy, the space of urban growth of Beijing city has been speeded up and a dramatic influence on its urban environment has been exerted. Urban growth, vegetation area changes and their influence on the thermal environment of Beijing city were analyzed based on the three scenes of Landsat5 TM data acquired on September 26th 1987, August 28th 1994 and August 31st 2001, separately. Radiometric normalization between the three images from different dates was made firstly, followed by information extraction of urban growth and vegetation changes. The generalized single channel algorithm proposed by Jiménez-Munoz J C, et al. in 2003 was applied to retrieve land surface temperature (LST) and thermal environmental changes were examined based on the normalized LST. The result shows that urban growth area coincides with the thermal intensified area and a good correspondence exists between vegetation increased area and thermal relieved area or no change area. The characteristics of urban growth and thermal intensified area changes were similar, both growing from the center of Beijing city to its outside in accordance with the ring road system.

The confirmation of spatial conflict is the key issue for detection and adjustment of spatial conflict.The method for confirming the spatial conflicts between line objects is discussed in this paper.Many factors such as the precision of spatial data,object types,the temporal and the semantic characteristics of objects are considered in this method.The metadata,DLG,DRG,image data and the experience of experts are also used to confirm the spatial conflict semi-automatically.

In order to deal with the complicated operation and poor expansibility in integrating spatial data,we design a grid oriented Java GIS framework for the spatial data access and integration as well as the key technology of GIS grid service upgrade.Also we put forward a cross platform Java GIS prototype to combine the topological model,Java rich client framework and data grid components together with the uniform standard to build high performance grid computing oriented Geographic Information System as well as to provide a best practice for the realization of prototype development efficiency towards grid environment.

Urban land-use change is a complex dynamic and spatio-temporal process and how to simulate this process is a key problem in the research field and Cellular Automata Model has obvious superiority.In this study,a TM image in 1988 and two ASTER images in 2001 and 2004 respectively of Fuzhou city were used to extract the urban land-use information of the research area and Cellular Automata Model was used to simulate the change of urban land-use in the following 20 years from 2001 and the precision was tested by the ASTER image in 2004.The result shows that urban land-use will expand at a speed of 7km²/y and the leading direction of development will be the Nantai island with rural urbanization as the other key factor,at the same time the urban green area will shrink.

In order to solve the problems occurred in the existing Marine Information Management System,one combined system structure-B/S and C/S based on .NET technology-was introduced,and a new base framework of the Marine Information Management System was also put forward. Because of the marine information,which was characterized by its abundance,hugeness and complexity,the method for those information management was studied and implemented. Finally,a new Marine Management System based on the ArcGIS Server technology was brought out successfully,the automation and digitization for the marine information management was carried out throughout Fujian Province.

As an important component of input data, soil information directly impacts the accuracy of the simulation of hydrologic model. Sensitivity of SWAT model to detailed soil information was investigated through comparison of the simulated stream flow produced by using SSURGO and SoLIM as different soil input data. A case study was conducted in Brewery Creek, a 19.5km² area catchment in Dane County, Wisconsin. The simulation results before and after model calibration both indicate that there is only slight difference between the simulated streamflow. This study reveals the weak sensitivity of SWAT model to detailed soil information in the hydrological modeling of a small watershed. The main reason for lack of insignificant difference is that soil information was highly aggregated in the model and that the use of Curve Number as means for representing soil variability in the model also muted the impact of detailed spatial information.

The process and characteristics of urban expansion are analyzed using fractal dimension and compactness based spatial morphologic measurement coupled with land use change survey. The Tianjin city is selected as a study case with nine Landsat TM images abstracted in 26 years. The results showed that there are two terms of high speed urban expansions in this period. The latter one expanded fast than the former one but its morphologic metrics change speed was lower than that of the former. This means the latter term was more rational and regular. The metrics of urban morphology and urban land use are compulsory to each other which can be used to satisfactorily describe the process and characteristics of urban expansion.

The research of Spatial Decision Support System is an important branch of modern GIS.This paper analyzes some problems facing SDSS today by introducing grid technology and open grid services architecture into SDSS,puts forward the architecture of a grid service-based SDSS,then describes the functions and logics of all parts of the architecture in detail,and discusses the running process of the architecture by taking the application to the hurricane surge field as a case.Finally,it identifies the advantages of the grid service-based SDSS.

This paper firstly depicts the necessity of the cyclic economy from the background of Cyclic Economy,then introduces the spatio-temporal characteristic of the object in the cyclic system,spatio-temporal flow characteristic of information and the increase and decrease of entropy,and selects a characteristic scientific demonstration district as its support to demonstrate the advantages of information flow used in this district.Lastly,the penman expounds his opinion about the effect of information technology in the course of cyclic economy development and the trend of cyclic economy.

Based on Digital Line Graphic(contour,scale:1/100 000) ,firstly,the authors produce DEM(Digital Elevation Model,30×30m ) of Fujian Province by GIS special interpolation technology under the environment of ARC/INFO software.Secondly,under the environment of hydrologic model of ARC/INFO software,through DEM pretreatment,flow direction analysis,flow accumulation analysis and watershed recognization,1 435 small watersheds are extracted.The result of the study shows:In the mountain area,the watershed boundary line is almost identical to the ridge line,but in the flat country,the result is less satisfactory because of DEM precision,devious coastline and bitty bay,the watershed boundary line needs revising artificially further.The fast extraction of the watersheds based on DEM saves manpower and material resources greatly,which is feasible according to efficiency and precision.With constant improvement of the precision of DEM,this method will lay solid foundation for the quick analysis of spatial combination characteristics of various physical geographic elements within the range of watersheds in the whole province,data management of observation stations synthetically,and the visual browse,inquiry,statistics and hydrology of model analysis,which will promote the implementation of eco-environment managements,such as eco-environmental protection,eco-environment con-struction,etc.

GML(Geographic Markup Language) is gradually accepted and widely used as an encoding,storage and exchange format for spatial information,and it offers a powful tool for implementing spatial information sharing and WebGIS development. As a graphic file format standard in the network era,SVG(Scalable Vector Graphic) represents graphic transmission development direction on the web,which integrates vector graphic,bitmap image and plain text merits and is naturally compatible with the network environment,so study on GML and SVG-based WebGIS and its application will have extensive practicality and application value. In this paper,GML and SVG are discussed firstly,especially in the role of open WebGIS,then an open WebGIS architecture is put forward which uses GML to store and integrate geographic information and using SVG to implement web display and operation for geographic information. Finally,taking a campus map issuing system as an example,an open WebGIS application system is set up and discussed.

Based on the historic literatures and remotely sensed images, this paper studies the spatial-temporal characteristics of Guangzhou city's spatial morphologic evolution in recent one hundred years, and summarizes the historic characteristics and the laws of urban development since the formation of Guangzhou, especially the period since the implementation of reform and open policies. On the whole, Guangzhou experienced two major stages, i.e., traditional urban development period before 1923 and modern urbanization development period from 1923 to 2004, covering several sub-periods of stabilization period and fast development period. The total increased built-up area of the city from 1979 to 2004 is 385.56 km², an expansion of 3.46 times, and the average expansion rate is about 15.43 km² per year. Many factors have contributed to the urban spatial morphologic evolution. But four major driving forces, i.e., economic development, institution and policy change, city planning and transportation system are the most important factors. Physiographic environment is the base of the city expansion;economic development is the inherent impetus for the evolution of the spatial morphology, and city planning plays a vital guiding role to the construction and development.

The purpose of intelligent GIS is to realize the natural language interaction between GIS and users.Two main problems of intelligent GIS are how to automatically extract spatial information from natural language and how to bridge the semantic gap between unstructured spatial information in natural language and structured spatial information in GIS.The previous research focuses on natural-language spatial relations.One of its basic tasks is to explore spatial terms and syntactic patterns in natural language.In this paper,the basic problems of natural-language spatial relations are described,and then Chinese spatial terms and syntactic patterns are discussed in detail.Finally, a few syntactic patterns are presented for query representation of natural-language spatial relations in GIS.

The implementation of circular economy is the important guarantee for the realization of the sustainable development.Based on the research results of regional sustainable development decision support system,this paper combines with the technique of spatial data mining and puts forward the design of regional circular economy framework.The application of SDM on regional circular economy is also mentioned.

Based on the conceptive model,a method of vision geographic modeling relevant to the virtual geographic environment was introduced.Utilized Object Oriented Programming,an extensible framework of vision geographic modeling was constructed.Moreover,the key techniques which were used to perform the visual geographic modeling were displayed as well.All these applications show that the framework is both extensible and adaptable,which not only supports the compound model constructed by the model components,but also benefits the realization of the geographic phenomenon,mechanisms and processes correctly.

Geocollaboration is a kind of group work that people take part in together to solve some geographical problems under a certain environment, such as map, virtual reality environment and so on. This article briefly reviews the state of the art of geocollaboration and its collaboration model, then it presents an agent-based collaboration model. Different from other collaboration models’ decomposing methods (such as the decomposing granularity of Activity Model is activities, and that of Role Model is roles, etc.), this collaboration model’s decomposing granularity is computing units, such as geographic models, user avatars, coordination controllers, message transport services, and so on, all these units can be encapsulated by agents. At the end of this paper it assesses the usability of the model, it is proved that agent-based collaboration model can exert the virtues of agent, such as autonomous, reactive, collaborative features as well as its high expansibility.

Multilayer Brower/Server model is a domain tend to the mature system design thought in computer network software engineering. Constructing WebGIS by the multilayered model thought is possible to solve many problems system deep level application development,hence it has become one of the GIS research hot spots. The lake scientific database WebGIS service system aims at promoting data sharing and providing basic data support for the scientific research workers. Based on the analysis of the comparison of the several kinds of domestic and foreign data issue system,taking the data warehouse idea as an instruction,this paper has designed lake database WebGIS system with the aid of multilayered B/S model. The onstage used the active server page (ASP) and the Web server used Microsoft Corporation Internet Information Server (ⅡS). The intermediate level used the SuperMapIS as map server,and the space database engine is used in the magnanimous data which managed SQL SERVER. This article,focusing on the method and the technology used in the process of constructing the system,has discussed the application and realization of WebGIS based on multilayered B/S model.