Key technique of floods prevention information system based on GIS

New theory for construction of floods prevention information system based on geography information system (GIS) is presented in this paper. The new theory is called spatial temporal mathematical basis for large-scale GIS and the digital earth overcome the shortage of traditional spatial mathematical base. New theory based on the mother earth coordinates system adopt isometry skive column projection. The traditional transition between earthly surface and horizontal plane was be extended to the transition between earthly surface and horizontal surface by the new map projection proposed in new theory. In order to make scientific decision of floods prevention, the floods prevention information system of Xianning city was developed based on GIS technique. The new model was presented in this paper in order to enhance the efficiency of floods prevention information system construction and satisfy the requirement of digital earth. New model adopted vector and raster technique based on the new theory. And in the new model the digital raster graphics (DRG) were made as context reference of system, consumers can label the symbol of special entity as vector object at any time on such reference. The floods prevention information system based on GIS offered scientific assist for floods prevention and management of Xianning city. System obtains satisfactory effect and it indicates that the new theory and new technical model proposed in this paper have good foreground for employing to execution. Keywords-digital earth; spatial mathematical basis; DRG; floods prevention information system