Path planning is a process to find the optimal path from the starting node to the destination node.Tens of algorithms have been designed to resolve the shortest path problem,in which the Dijkstra algorithm is always thought to be the most mature and classical one.However,its higher time complexity greatly restricts its practical application.Besides,for most path planning algorithms,the road network is considered as an ordinary plane network and the spatial distribution characteristics are ignored,therefore,the path planning algorithm can not do well in real road network.In order to improve the searching efficiency of the traditional Dijkstra algorithm and to meet the requirement of real-time vehicle navigation,a path planning algorithm based on SuperMap is designed by utilizing the network editing function of SuperMap GIS platform.Firstly,with the spatial distribution characteristics,a road network is built in SuperMap.In this process,we take three-dimensional transport and one-way road network into consideration,making the road network built in SuperMap able to reproduce the real road network.For three-dimensional transport,we set the parameters of non-broken lines and make sure the roads not in the same plane have no intersections;for one-way roads,the forward resistance and reverse resistance are set with different weights.Secondly,in order to improve the searching efficiency of the traditional Dijkstra algorithm,we propose a method to restrict the searching area.According to the coordinate relationships of the starting node and the destination node,we create a hexagon area,which contains the staring node and the destination node,as the restricted searching area,and make the algorithm able to search the shortest path within the restricted searching area on the theoretical basis of the classic Dijkstra algorithm.Thirdly,based on the actual needs,the path planning algorithm with certain constraints is designed.The constraints are prohibit a certain way and must pass through a certain point.At last,we apply the algorithm proposed in this paper to urban road network and compare it with traditional Dijkstra algorithm.The results show that,due to the searching area is restricted reasonably,the two algorithms get the same shortest path,but the time spent by the algorithm proposed in this paper is much less.Besides,the algorithm proposed in this paper can do well in path planning with constraints.Thus,the improved Dijkstra algorithm based on SuperMap GIS has a strong practicability,and can be used in real-time vehicle navigation.

Geospatial data is a kind of strategic information resource and is widely used in economic,social and environmental applications.GIS vector data is closely related to the overall situation of socio-economic development and national security due to its high production cost and high precisions.In recent years,researches about copyright protection of GIS vector data mainly focus on copyright marking techniques.To meet the requirements of copyright protection for spatial data files,a real-time copyright protection scheme for spatial data files is proposed in this study,based on the Copyright Marking technology,especially on the Digital Watermarking technology which was only used for the authentication,file system filter driver technology and encryption technology,which can be used for dynamic encryption and decryption of data files and real-time detection of copyright marking.This scheme achieves the purposes to keep confidential,detect copyright marking in a real-time way and control access.In addition, it lowers the limitations on the capacity of copyright marking information and the robustness of embedding algorithms.

With rapid development of city construction,emergency events that endanger national security and people's safety occurred on occasion.It is necessary to establish an emergency management system and comprehensive emergency information system.Pipe analysis is a main application of GIS in the City Emergency Management Model.We can manage urban underground pipeline network and store information into computer orderly for data updating and resource sharing.The pipeline data in Guangzhou higher education mega center are used to demon- strate the application.A city emergency management model is built in the study by including three analysis modules (section analysis,vertical distance analysis,and analysis of pipe burst),and Guangzhou higher education mega center is selected as a study area for the three analyses by the visualization platform,By studying the Guangzhou higher education mega center pipeline network the authors analyze the three modules on the scope of application at the same time.The administrators of the pipe management can also make analysis of pipe burst,which is the most important spatial analysis function in pipe network analysis.The three modules of the emergency management model can be applied in pipe design,construction and service.

Based on the fact that the urban and regional geographic information development is quite uneven in China, this paper introduces an idea to measure the levels of geographic information development in urban areas using methods of questionnaire survey and case study. The authors discuss the natures and characteristics of geographic information from multiple perspectives, and present several development indicators such as professional and related organization, data investment and budget, data production and supply, data quality and standard, information infrastructure, related law, policy and regulation, application and benefit, and degree of data sharing. The related development degree index, questionnaire design, and case study design should consider these indicators carefully according to the research purpose. Finally, it is suggested that the government administrators and / or professional organizations should conduct a nationwide evaluation of urban geographic information development and formulate general strategies for China's long-term urban geographic information development and application.

Multi-source remote sensing data fusion is the development trend of remote sensing technology in depth. This paper analyzes in detail algorithmic application characteristics of multi-source remote sensing data from three levels of pixel-based, feature-based and decision-based fusion processings. Take Fengning County for example, specific applications of remote sensing data fusion methods in information extraction are illuminated. The data used in this study is firstly pre-processed, then the principal components of Landsat TM data in 1999 are analyzed, the first three principal components account for 97.8% of the total information, the resulted image of inversed principal components transformation is clearer and has more abundant levels. To extract information from remote sensing image, we select the fusion image from Landsat TM pan and multi-spectral bands after principal components transformation, color composition scheme of bands 4, 3, 2 and bands 5, 4, 3, and vegetation index and greenness index after tasseled cap transformation are analyzed, the remote sensing image information fusion with DEM and spatial data of GIS database can also improve the accuracy of remote sensing information extraction. Problems to be resolved and future direction of multi-source remote sensing data fusion are put forward.

Marine GIS has become one of the important developing domains of GIS sciences Both scholars in GIS and in oceanography are interested in it The basic representation is considered as one of the most important problems This article presents a data model to solve the problem It includes three database: basic database, data warehouse and database for marine phenomena; two data analyzing mode: data pre disposing and feature analyzing It uses multi level extended grid data structure with two kinds of global grid scheme One is equal angle, the other is equal area grid scheme They have some new marine chara cteristics.

With the advance of the society and economy,Landuse is changing rapidly.Which results in the difficulties in timely dynamic monitor and updating the information of land use using traditional methods.Therefore,A better method to solve this difficulity.This paper discusses the principles and methods for dynamic monitoring landuse changes and timely updating the database of landuse using the morden spatial information technology,which are called '3S' technology, and provides the system development model and technique system by studying on the application principle about implementing dynamic monitor and updating for land use change by combining RS and GPS. Change data delamination and integrating analysis,object-oriented superposition-updating process and establishing the data fusion index are key technologies.

This article estimated the precision of the precipitation simulated by 15 IPCC AR5 (the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, IPCC AR5) GCMs (Global Climate Models) and the multi-model ensemble (MME), based on the observed precipitation from 660 stations in China during 1996 to 2005. We firstly extracted the model simulation value at the corresponding position of the meteorological station, using the bilinear interpolation method, and took the average value of different models at the same station as the multi-model ensemble simulation value, then estimated the precision of the precipitation simulated by 15 IPCC AR5 GCMs and MME based on the observation of meteorological station. There were four evaluation parameters, including Corr (correlation coefficient), Bias, MRE (Mean Relative Error), and RMSE (Root Mean Square Error). Results show that the biases of the average daily precipitations simulated by IPCC AR5 GCMs present a gradually downward trend from northwest to southeast, and the RMSEs show a gradually increasing trend from northwest to southeast, while MREs in the east are less than those in the west. 82.3% of the average daily precipitations simulated by MRI-CGCM3 have relatively small biases, ranging from -0.5 to 0.5. The precisions of average daily precipitations simulated by BNU and MIROC-ESM are lower than that of others. Compared with other models, the MME simulation has the largest percentages of which the correlation coefficients are more than 0.5, MREs are less than 0.5, and RMSEs are less than 4mm, which accounted for 64.8%, 25.8% and 86.4% respectively. And the percentage of the biases ranging from -0.5 to 0.5 is relatively large, which is 56.7%, indicating that the simulation precision of MME is better than that of any other GCMs, and the MME can reduce the uncertainty of a single GCM simulation in future scenarios. Therefore, it is more scientific and reasonable to select the precipitation simulated by MME as the climate change condition, while studying subjects related to climate change.

The existing finite element numerical simulation method of groundwater flow has some defects in the three-dimensional visual spatial analysis and the expression of numerical calculation process and simulation results. In order to solve this issue, the key steps of the finite element analysis process including the conceptual model construction, spatial discretization, hydrogeological parameters extraction and initial condition assignment are taken into consideration respectively. Based on the finite element method and 3D GIS platform, the method and technique framework of the groundwater finite element numerical simulation under 3D GIS are proposed with the supports of GIS spatial analysis algorithms and computer graphics theory. In addition to describe the technique framework, the core algorithms’ implementation details are given and the complete process of 3D GIS groundwater flow simulation is presented. The groundwater simulation example demonstrates that the proposed method and technique framework are capable of simplifying the finite element analysis process and improving the calculation efficiency of the model. The whole technique framework can be integrated into 3D GIS platform, and furthermore the visualization of simulation process and calculation results can be achieved eventually.

Heatwave has become an extreme meteorological disaster which occurred frequently during the summer. Moreover, heatwave could evidently affect the healthy conditions of residents. Thus, study the spatial pattern of heatwave health risk would be helpful for us to prevent from and respond to the impacts of heatwaves. Using the historically meteorological datum of Xiamen, this study built a database of heatwave cases and analyzed the basic characteristics of heatwaves in Xiamen. Taking a heatwave event occurred in 2010 as a case, we analyzed the spatial pattern of heatwave health risk by using both the remote sensing data and the demographic data. It is concluded as the following statements. (1) The intensity of heatwaves in Xiamen is quite low, but its frequency is rather high. An intensive heatwave occurred occasionally. (2) The regions with high health risk are located in Xiamen Island, lying from the northeast toward the southwest. The regions with the highest healthy risk are located in the northern and southeastern Jiangtou sub-district, Huli district, and the most area of Xiagang sub-district and Siming district. (3) The human health risk pattern of Heatwave is associated with the spatial distribution of environmental and demographic factors. Generally, this study promotes and extends the scientific knowledge on the health risk of heatwaves.

The urban built-up area boundary is important basic information for urban studies, and is also the premise of the implementation of urban function space layout, the implementation of boundaries control. Accurate extract urban built-up area for urban construction, management and research has important guiding significance, but also reflects the city's comprehensive economic strength and the level of urbanization, one of the important indicators.The DMSP/OLS night light data has been widely used in the extraction of urban built-up areas. But due to the effects of saturated, diffuse, and low resolution problems, it is still a huge challenge to rely on the DMSP/OLS NTL mapping the urban built-up areas. In order to overcome the limitations of the data source itself, In this study, the application of hierarchical expert knowledge analysis, multi-source data extraction of the thematic information layer by layer into the extraction process, the construction of urban built-up area for the level of expert knowledge model to achieve the city built-area refinement extraction. The urban index （VANUI） was constructed by combining 250 m MODIS NDVI data with 1 km DMSP/OLS data. Based on the administrative boundary, the statistical area of the area is divided into the administrative boundary of each prefecture-level city, and the optimal segmentation threshold of each administrative unit VANUI feature image is calculated according to the regional segmentation method, so as to obtain 250 m urban boundary space information range. Meanwhile, Due to the low spatial resolution of the DMSP/OLS luminous data and the narrow range of light and light values, there is still a large gap between the optimal segmentation threshold and the built-up area. Therefore, this study proposed the maximum autocorrelation double threshold extraction method. The 30m Landsat 5 NDVI data were fused to obtain the maximum autocorrelation quadratic NDVI threshold in each 30m seed region by multi-scale segmentation of the regional threshold segmentation. According to the maximum autocorrelation threshold of each potential built-up area, each potential built-up area is revised one by one, and finally 30m urban built-up area is obtained. This paper takes the Beijing-Tianjin-Hebei region as the research area, the experimental results show that the total precision of extracting urban built-up area by multi-source remote sensing cooperative method is 92.9%, and it has higher validity and reliability in spatial distribution and statistical data. The results show that the results of the urban built-up area extracted by this method are not only the overall accuracy, but also the spatial extent of the visual interpretation, and the relative error of the statistical area in each prefecture-level city is small, which verifies the reliability and validity of the method in spatial distribution and statistical data, and avoids the error caused by subjective threshold selection. DMSP/OLS data can be used not only for urban area extraction, but also for the intensity and scope of human activities. Therefore, in the follow-up study, based on the identification of urban built-up area boundary, combined with the quantitative analysis of luminous data and evaluation of urban development area outside the expansion trend and internal dynamic changes for the DMSP/OLS luminous data to give full play to its effectiveness, Economic and historical values play a positive role in promoting.

Terrain position is the basic morphologic feature on the surface of the Earth. The classification and extraction of terrain position have been widely applied in many research fields such as landform evolution, digital soil mapping and landscape ecological mapping. Proposed by Kang X et al. (2016), the multi-scale Geomorphons method maps terrain position by recognizing the morphology of each interest cell in a DEM according to its relative altitudes within the neighboring window. Multi-scale Geomorphons method can avoid the shortnesses of other classificaton methods, which are caused by different terrain attributes and a single analysis scale. However, there are still some drawbacks in the multi-scale Geomorphons method. For example, the classification results are fragmented and the domain of the analysis scale is difficult to determine. To solve the above problems, this paper presents a new method to classify terrain position, which is based on object-oriented segmentation and multi-scale Geomorphons. First of all, we propose an approach of determining the domain of optimal analysis scale of the multi-scale Geomorphons method. Then, the multi-scale segmentation and classification methods are constructed according to the initial terrain position data via the multi-scale Geomorphons method. At last, the presented method is evaluated by the experimental data of the DEM with 5 m resolution in the loess plateau region of northern Shaanxi. The experimental results show that: (1) the method of mean change-point analysis can effectively solve the problem which is difficult to determine the domain of the analysis scale of the multi-scale Geomorphons method. The domain of optimal analysis scale of the sample area is 5×5 to 33×33 cells. (2) The layer of each terrain position type with the value 0 for non-type cells and 255 for type cells is suitable for multi-scale segmentation. The parameters (i.e. scale, weight of shape and weight of compactness) for multi-scale segmentation have deep influence on segmentation results. There is optimal segmentation parameters for a experimental region. There is optimal segmentation parameter for an experimental region. (3) Comparing with the multi-scale Geomorphons method, the classification results of the present approach are more integrity and reasonable in the aspects of morphology correspondence and geological interpretation.

Urban sprawl is a common problem in the process of rapid urban development. Due to differences in economic systems and other aspects, the characteristics and driving factors of urban sprawl in China are quite different from those in Western countries. The urban sprawl in China is accompanied by the disorderly development of land in the process of rapid urbanization. Based on the summary of domestic and international theoretical and empirical research, this paper chooses the elasticity of urbanized land to urbanized population to characterize the urban sprawl. This article analyzes the urban sprawl of 214 prefecture-level municipal districts from 1996 to 2014, and summarizes the following characteristics of its sprawl tendency: stable sprawl, adjustable sprawl, steady and high-speed sprawl, steady and low-speed sprawl. We summarize the following characteristics of its sprawl intensity: no sprawl, general spread and highly sprawl. In addition, we construct the panel model to explore the driving factors of urban sprawl from the aspects of the industrial structure, the government expenditure, the education development level, the traffic development level, the globalization level and market-oriented level. The results are as follows: (1) the issue of urban sprawl has a path dependence. Under the guidance of the development program with rapid economic growth, the high level of sprawl will continue for the rest of the year. (2) In the urban development mode oriented by economic construction, the development of secondary sector will significantly aggravate the urban spread. However, by promoting the development of the tertiary sector, local governments can attract foreign investment to optimize the structure of economic development and alleviate the problem of urban sprawl. (3) The influence of road construction, marketization level and college education level on the spread of cities is small or insignificant. Finally, we summarize the types, drivers and path dependence of urban sprawl and put forward policy proposals to control the urban sprawl from the perspectives of industrial structure and development.

Land use mapping using remote sensing techniques supplies essential datasets for scientific researches including global climate change, regional sustainable development and so on. The evaluation information on the accuracy of the land use mapping determines the integrity, reliability, usability, controllability and shareability of the land use maps obtained by the applications of remote sensing techniques. In this paper, the methods, processes and results of multiple temporal land use mapping for China's coastal zone using remote sensing techniques were overviewed, and the land use maps in 2010 and 2015 were selected for accuracy evaluation. The validation samples were collected based on Google Earth and the confusion matrices were established for the whole coastal zone and its sub-regions, respectively. Then, the overall accuracy and Kappa coefficient were calculated. Main findings are as follows: (1) Results of land use mapping in 2010 and 2015 using remote sensing techniques achieved high accuracy. For the entire coastal zone in China, the overall accuracy came to 95.15% and 93.98%, with the Kappa coefficients of 0.9357 and 0.9229 in 2010 and 2015, respectively. (2) The accuracy of land use mapping in China's coastal zone exhibited obvious regional differences. The best accuracy was found in the coastal area of Jiangsu province in 2010, and very high accuracy were found in the coastal area of Hebei-Tianjin, Shanghai city, Hainan province and Taiwan province in 2015, while the worst accuracy was found in the coastal area of Fujian province in both 2010 and 2015. (3) The accuracy of land use mapping in China's coastal zone exhibited obvious typological differences. The very high accuracy (both producer precision and user precision) were achieved for farmland, forest, grassland and saltwater wetlands, and the high accuracy for built-up, freshwater wetlands and human made saltwater wetland, while the worst accuracy for unused land. (4) The misclassification between cultivated land and forest land, construction land and grassland is quite significant. Inland water bodies were easily misclassified into cultivated land, forest land and construction land. Artificial salt water wetlands were easily misclassified into cultivated land and construction land, and unused land. It was easy to mistakenly classify the unused land as cultivated land. These are the issues that should be paid more attention during the continuous update of the land use maps in the future. This study provides supports for the dynamic monitoring and scientific researches on coastal land use changes.

The new generation of spaceborne laser satellite ICESat-2 (the Ice, Cloud, and land Elevation Satellite-2) of NASA (National Aeronautics and Space Administration) has adopted a newly designed micropulse photon counting system, which is the very first time that this technology gets applied in the space environment. Thanks to the high sensitivity of single photon detection technology, it can be seen from the currently released data product (both from the airborne simulators and the simulation data) that there is huge noise in the atmosphere and even below the ground. Therefore, preliminary research on these relevant experimental data to investigate the methods for separating signal photons from noise photons are important for the future applications. MATLAS data, which simulate the expected performance of the ICESat-2 ATLAS (Advanced Topographic Laser Altimeter System) instrument, was chosen to test our machine learning-based approach from two test sites in Oregon and Virginia in the United States. We first derived 12 features, such as the kNN (k-Nearest Neighbour) distance, based on the characteristics of photon point clouds data. Then we applied feature selection techniques by ranking variable importance using Random Forest. Three most representative features were chosen according to the variable importance ranking and we built a Random Forest classifier trained by the sample points we had selected. The established models were further applied to the whole study area. The final classification results indicate that the classifier we constructed had good performance to distinguish signal photons from noise photons. In terms of the mean values of the statistical indicators in the test sites, the overall classification accuracy was 96.79%, and the Kappa coefficient was 0.94. The producer and user accuracies were 97.1% and 96.8%, respectively. Additionally, the results show that our method not only worked well on data of relatively lower noise rate on flat terrain surfaces but also achieved good results for those with higher noise rate on complex terrain surfaces. To conclude, our method showes good potential to be applied to larger areas, for especially the classification of the photon counting LiDAR data in the future.

Land Use and Land Cover (LULC) classification products play an indispensable role in ecosystem assessment, climate change simulation, national geographical condition monitoring, and macro-control policy analysis at the global scale; consistency analysis is the precondition of applying various LULC classification products. This paper assessed the area consistency and spatial consistency of five LULC classification products - MCD12Q1-2010, GlobCover2009, CCI-LC2010, FROM-GLC2010 and GlobeLand30-2010- in the global coastal zones. The five products were compared in terms of the deviation coefficient, correlation coefficient, error matrix, and spatial confusion of LULC types. The main findings are as follows: (1) The spatial patterns of LULC in five products demonstrate relatively strong overall consistency, but can have significant local inconsistency. (2) The five products are qualitatively consistent yet quantitatively inconsistent in classifying the LULC in the global coastal zones ? in terms of structure, water ranks top one, followed by forest and unused land, next are farmland, grassland and shrubland, and lastly wetland and artificial surface, yet the exact area of each LULC type differs among different products. (3) For the correlation coefficient, overall accuracy and Kappa coefficient, MCD12Q1-2010/GlobCover2009 have the minimum values, 0.8814, 67.46% and 0.5748, respectively; while GlobCover2009/CCI-LC2010 have the maximum values, 0.9869, 81.50% and 0.7505, respectively; it is because GlobCover2009 and CCI-LC2010 obtained from the same production organization have the same classification system, while MCD12Q1-2010 is different from GlobCover2009 in terms of the production organization, data source, classification system, and classification method. (4) For the spatial confusion/misclassification between any two different products, grassland, shrubland, and wetland have the highest mix-up ratios, followed by farmland and artificial surface, and lastly forest, unused land, and water; this difference is because forest, unused land, and water have distinctive spectral characteristics and clear spatial textures, while grassland, shrubland, and wetland have similar spectral characteristics and fuzzy spatial distributions. (5) There are 28.81% land area in the global coastal zones with relatively low consistency, i.e., with severe spatial confusion; specifically, the misclassification of farmland, forest, grassland, shrubland, wetland, and unused land has direct influence on the spatial consistency of the five products. This paper is hoped to serve as a reference of selecting data from the five available LULC products for researching coastal zones.

Cadastre is a tool which is used to manage national land resources and assets.Traditional cadastre is two-dimensional one which takes parcel as basic management unit to administer land surface right,and its theoretical basis is consistency of the right nationality of the same parcel in the vertical direction,namely the ownership rights of underground,surface and ground space belong to the identical obligee.Due to the backwardness of the past economic development,land use mainly concentrated on the two-dimensional surface and it isn't necessary to extend land use into the third dimension.Therefore,traditional two-dimensional cadastre which takes surface right as core can satisfy social demands well.In recent decades,the rapid increase in population and intensified urbanization make the land use of urban areas,especially business centers under rising pressures.In order to provide more available space,city development extends unceasingly to the third dimension.Three-dimensional land use makes the subject of property become pluralism in the vertical direction,namely underground,surface and ground space can be stratified development and are distributed to different obligees.Tendency of Three-dimensional land use brings forth challenges to traditional land management theories and methods.Three-dimensional cadastre also needs a kind of basic unit like two-dimensional land parcel to register and manage property in three-dimensional space,this kind of three-dimensional basic unit is called property volume in this paper.We will take right entities such as land and property as basis,use right space as reference,research dividing mode of land and property in three-dimensional space,analyze existing form,dividing mode and space form of two kinds of basic unit,generalize theirs basic characteristic.Based on these substantive characteristics,we give the definition and representation of property volume,and test the correctness and validity of the given property volume.

Similarity measuring of spatial topological relations is the important part of similarity measuring of spatial data, and also is the basic and key technology of spatial data retrieval and spatial scene query. Its meaning is to measure the similarity of topological relationships between multiple data entities in different sources, different sources scales of the same region. Common topological relations have been abstracted into nine topological predications. Current researches mainly focus on the topological relations similarity measuring between two simple entities, but mostly do not involve topological relations similarity measuring for the entire data sets, as well as the complex line targets. In this paper we present a method of measuring simple topological relations based on 9- intersection matrix, that is, the distance between two 9- intersection matrixes as the simple topological relations distance to measure the differences between two simple topological relations, so that we can get a simple topological relations similarity. Then considering the quantity similarity and dimension similarity between entity sets, we can get the simple topological relations similarity measuring model between entity sets. In this paper we establish a similarity measuring model of complex topological predication by using the strategy of decomposing- combination based on the simple topological relations similarity measuring model. Firstly, the complex topology relationship is broken down into a number of local topological relationships. Then through a combination of local topological relations similarity, we get the complex topology relationship similarity measuring model. At last, the method is used to measure similarity of different scales and different sources data. Experimental results show that the selection of cartographic generalization impact the topological relations similarity between entity sets mostly, and other factors with smaller impacts to the experimental data in this article. Experimental results also demonstrate that the topological relations similarity can be used to measure the changing degree of topological relations caused by the cartographic generalization.

Taking Chengdu region(sheet number H-48,national standard division range 1∶ 1 000 000 geomorphologic maps) as an example,this paper studies the production method of relief shading maps using software of ERDAS,MicroDEM and Global Mapper,and data source of SRTM-DEM.Then,the relief shading maps are color adjusted,effect optimized Photoshop software.After overlaying the relief shading map and geographical base map,the final relief shading maps are produced.The research shows:(1) Although each production method of relief shading maps has merits and demerits,but as to the results' quality and effect,the relief shading map made by Global Mapper is better than it made by MicoDEM,and the quality and effect of the relief shading map made by ERDAS are the worst;(2) As a strong image processing software,Photoshop plays an important role in the effect adjustment and quality optimization of relief shading map production;(3) As the relief shading map can represent more information content and better color effect,it puts forward a higher requirement and challenge for cartographer in color use,and in the judgement and adjusting ability for the representing effect.

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.

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.

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.

This paper describes the concept and contents of digital agriculture, its current status and davelopment trend The information technology, spatial technology, and micro-electronics technology make a revolution to traditional agriculture It is based on cultivation of big farmland, using advanced technology as background It is an agriculture technology system with the characteristics of integration and information It means that whole procedure of the cultivation, semination, irrigation, fertilizer, farmland management, protection of forestry, estimate of product, store, and administration will be characterized by digital, network, and intelligence, using technology of remote sensing, telemetry, tele-control, and computer in order to make every square meter have optimized using It will constitute an information agriculture technology system for monitoring and estimation of crop, caltivated area, and soil, current or dynamics analyses of crop growth, and factors of environment, diagnose forecast, cultivation step, management planning and decision support We first describe the application of remote sensing and telemetery in agriculture forecast, then introduce GIS, GPS, and automatic agriculture device, finally give the component of digital agriculture system.

This paper mainly discusses the meaning and origin of the term "virtual city", and highlights the functions of a virtual city such as the examination and evaluation of urban planning schemes, virtualization of urban functions and evaluation of urban operations.

青藏高原是全球独待的地质地理单元,素有“地球第三极”和“世界屋脊”之称。1964年以后,中国科学院先后多次组织对青藏高原及周围地区进行了大规模综合科学考察。这些考察获得了大量丰富资料和重要调查研究成果,填补了该地区的研究空白,取得了许多新的发现和认识,包括高原的形成与演化,自然资源及其评价等等。

We try to summarize the techniques used for digital map compilation for the marine territory of China in this paper. The new version of 1:1000000 geological and geophysical map series of China Seas and Adjacent Regions include five maps, i.e. the Bouguer gravity anomaly map, spatial gravity anomaly map, magnetic anomaly map, surface sediment distribution map and regional geotectonic map. The mapping area also covers part of the land and adjacent areas in addition to China seas. The geological and geophysical maps have not been renewed since the last map series published 20 years ago. And the maps published then were drawn by hands. Either precision or quality is not able to meet the demand of users. This time, we compile maps with MapGIS as a platform. Various equipments, such as computers, advanced digitizers and other facilities, are adopted for the map compilation. At first, we, using digital map compilation technology, standardized and unified all the data, including both the old and new data, and the data collected with different methods and from different channels. Rationale fitting technique and reliable coordinates transform are used to guarantee the quality of the maps. In the process of map compilation, a GIS database has been constructed. All the maps, including the base map and specific maps, were drawn on the MapGIS platform using point, line and polygons as legends and layers were designed and constructed according to the data available and the contents the maps need. The use of the MapGIS platform made us possible to ensure the precision of the maps and enhance the efficiency of map compilation. It is believed that the compilation and publication of the new version of 1:1 000 000 Geological and Geophysical Map Series of China Seas and Adjacent Regions will certainly help the readers better understand the basic geological regulations of China.

Current studies of map symbols mainly concentrate on the basic visual variables such as color, shape and size, which are commonly used in two dimensional maps. Recent technical advances and the ubiquitous use of smart devices have made three-dimensional (3D) maps (e.g., Google Maps and AutoNavi) increasingly popular. However, 3D visual variables, such as field of view (FOV) and viewing angle (VA) which play fundamental roles in visual information processing of 3D maps and spatial scenes, have been rarely investigated. This paper leverages eye tracking technology to explore the influence of such 3D visual variables on the interpretation of vertical, horizontal, angle and shape information in 3D maps. Specifically, we have recorded forty participants’ eye movements in four tasks by varying the FOV and VA values. Participants’ performances were analyzed by the quantitative metrics of effectiveness and efficiency. Statistical tests (two-tailed t-tests or Mann-Whitney U tests) were applied to each metric to test the significance of differences between two groups. Results show that FOV can significantly affect not only the effectiveness of interpreting the vertical and shape information perception, but also the efficiency of interpreting the angular information. Meanwhile, FOV has no significant influence on the efficiency of interpreting the vertical and shape information, the effectiveness and the efficiency of interpreting the horizontal information, and the effectiveness of interpreting the angular information of 3D maps. VA has no significant influence on the perception of horizontal, vertical or angular information. But it affects the perception of shape significantly. Furthermore, FOV and VA have interactive effects resulting in the difference of interpreting the angular and shape information giving the marginal significance. The results can provide implications to design 3D maps with higher usability and can be applied to improve the user interaction in 3D environments.

Shoulder line is one of the most effective terrain structure line used to describe the loess landform. It plays an important role in the study of the spatial distribution and landform evolution of the loess landform. Shoulder line lies on the boundary of the positive and negative terrain, where the elevation and slope of the loess surface reveal obvious changes. Many efforts have been done for the extraction of shoulder line, but these methods have disadvantages, of which the experimental process requires human intervention or the shoulder line is discontinuous. P-N terrain method can effectively extract the shoulder line, but while using this method to segment the positive and negative terrains, it tends to produce large amounts of broken polygons and classification errors, which affect the accuracy of shoulder line. This paper investigates a region growing algorithm to improve the P-N terrain method. Using the highest elevation of the local area as a growing point for positive terrain and the outlet as a growing point for negative terrain, four-neighborhood growth were carried out until they reached the boundary of the positive and negative terrains or a slope threshold. Then the edge detection method was used to extract the critical boundary. Finally, the morphological image processing method was used to eliminate burrs to get the final shoulder line. In order to verify the result, this paper used the 0.6 m resolution remote sensing image to get the relatively accurate shoulder line by visual interpretation. And then different results were compared using overlay analysis. It is revealed that the shoulder line extracted using the improved method is closer to the visual interpretation results. This method is an automatic way to extract shoulder line, which solves the inaccurate location problem of P-N terrain method. Meanwhile, this method keeps the integrity and continuity of shoulder line and avoids the emergence of broken shoulder line and closure shoulder line. The use of morphological image processing method in burrs removal also ensures the accuracy.

The Nanji wetland of Poyang Lake is a typical wetland of the water-carrying type. It is quite difficult to accurately extract the information of wetland landscape from remote sensing images with the traditional information extraction approaches due to the complicated hydrology conditions and arduous field verification, and moreover, the mud flat, swamp and infested water (schistosomiasis) is widely distributed in the region. This study chose GF image as the data source, with the auxiliary data of digital elevation model (DEM), normalized difference vegetation index (NDVI) and normalized difference water index (NDWI) to ensure the accuracy of information extraction. And it uses the object-oriented classification method to extract the landscape information of the Nanji wetland, which achieved some reasonable classification results indicating in the following part; (1) Based on the object-oriented classification of domestic GF satellite remote sensing images, which contains the spectral, spatial structure and texture features, this study makes a comprehensive utilization of the multi-source data in the classification calculation, and the precision of its classification result is significantly higher than the object-oriented classification of single-source; (2) The object-oriented method of multi-source remote sensing data has better distinguish ability for mixed pixels. It obtains a higher overall accuracy of 94.3275% and a Kappa coefficient of 0.9324, which indicates a distinctive high degree of accuracy and reliability. It has effectively solved the classification problem in extracting the wetland landscape of water-carrying; (3) This method makes up the deficiency in the object-oriented classification method of single-source remote sensing image, and it acts as an important reference and has the practical significance for effectively extracting the information of water-carrying wetland landscape through the domestic GF remote sensing image. Finally, we put forward some issues to be resolved and illustrated the future research direction of the object-oriented classification of multi-source data.