Historical Hypermap And Its Cartographic Visualization

As an important fusion point of historical geography and GIS technology,visualization of historical geographical information could restore geographical landscape in the past and find the rule of spatio-temporal variation,and makes great significance for history research and spatial turn of humanities and social sciences.It emphasizes the importance of the map as the space language,and using the map as a medium for the management,display,use and information mining of data.The emergence of hypermap provides a new idea for the visualization of historical geographical data.As the new style of map,it can realize information integration and navigation for multi-source heterogeneous data,and enhance map expressive in combination of multimedia and map.Therefore,hypermap,cartographic visualization and historical geographical information should be incorporated into a unified framework,and finally construct historical hypermap to reproduce the Nanjing during six dynasties.According to the research route of "theory-technology-practice",the study made efforts to explore the basic science issues,key technologies and concrete practice about cartographic visualization of historical and geographic information?We took Nanjing city during the Six Dynasties(Liuchao-Jiankang)as study area,used related literature,maps,photographs,and other media as the data base,made historical hypermap as a carrier of historical geographic information visualization and apply hypermedia information network as the organizational structure of the multi-source heterogeneous information.(1)Research on the theory historcial hypermap and its visualization.Based on the concept,model and development trend of cartographic visualization,and full consideration to the feature of history and geography information,the concept of"historical hypermap" was put forward for the platform of information visualization,furthermore,its concept,characteristics,visual emphasis and content were discussed.(2)The construction of the concept and logic model for historcial hypermap.The concept model described the characteristics of historcial hypermap from the content,the users,information structures and the display.The logic model was divided into the basic geographic information framework and the hypermedia information network layers.The former was the spatial information reference,while the latter as a core part of the model realized multi-source heterogeneous information integrated based on spatial cues.(3)The design of visual method for historcial hypermap.The technical methods of cartographic visualization were expored in terms of the historical space elements,historical events,hypermedia information network and other elements.Representation of historical space elements were through different combinations of visual variables,and prevented information overload by aggregation algorithm.Dynamic display of historical events was based on action,which action aggregation construct the sequence of events,and action decomposition into a specific unit to achieve structural display.Through the level division of the navigation structure,sort and merge of media elements Hypermedia information network applied a divergent hierarchical information navigation mode for each unit through the level division of the navigation structure,sort and merge of media elements.Other elements include the relationship network made by tree layout and Force-Directed Graph,as well as panoramic display based on real scene.(4)To establish prototype of historcial hypermap and hypermedia information system.Based on the theory and technology of historcial hypermap,this study collected about historieal geographical multimedia data during the Six Dynasties in Jiankang,and constructed hypermedia information system about the Six Dynasties Jiankang.The system displayed vector points,raster map and network map,historieal event in sequence,hypermedia information network hierarchical navigation and multimedia data.