Spatial-time Transformation Model And Algorithm In GIS

Along with the development of spatial information gathering methods, the updating speed of spatial data is much more faster and the relevant analysis is required to be dynamic and real-time. Current GIS systems, which could only represent geography elements at certain time are lack of the ability of temporal analysis. Therefore, temporal GIS (T-GIS) has been a important and focal aspect of GIS research.The contents of T-GIS could be included into two points. The first is the problem of spatio-temporal data model and spatio-temporal database. The other is the problem of spatial-time analysis and visualization. Both of the two problems are concerned in the research work but our most important research is on the latter problem. The main object of T-GIS is to build intellectualized data processing method and cognitive model which can be used in assisted decision-making based on spatio-temporal database.The research analyzed different spatio-temporal data model and spatial-time analysis techniques. Then spatial-time transformation models based on vector data and raster data are introduced individually. The models have been applied on the problem of shoal changes. The main contents of the research are listed thereinafter:1. Event-based spatio-temporal data model and State-based spatio-temporal data model are analyzed and compared in details. Different spatio-temporal data model are applied in spatial-time analysis on the basis of their own characteristics.2. The spatial-time transformation model based on vector data is introduced and achieves the interpolation ability. The model brings smooth and continuous visual effects in the case of few time-stamps.3. The spatial-time transformation model based on raster data is developed by improving classical cellular automata. The model could simulate geography process by confirming some transformation rules. It also overcomes some disadvantages of classical CA.4. The models above have been applied on the problem of shoal transformation and achieved considerable effects.