Modeling And Rendering Of Floods And Forest Fire Disaster Based On Three-dimensional Digital Earth

With the rapid development of modern society, the population grows faster and faster, and the density turns to thicker and thicker. In case of floods and forest fire disasters occurred, the lack of effective affected area simulation method would cause more serious damage. Now most of the researches, limited to specific region, which are based on two-dimensional geographic information systems, can not provide global decision and damage assessment services. Nowadays, great progress has been made in these two disaster domains, as the representative of the digital three-dimensional GIS matures, all these technologies provide strong support to the paper.This thesis focuses on building a global common use of flood and forest fire disaster model. In detail, the main work and contributions are described as follows:A three-dimensional Digital Earth based computation region extraction method is put forward. A Digital Earth based computation gird simplified model is constructed, and a computation region extraction method which reduces computation amount is proposed.A digital earth-based two-dimensional flood simulation and rendering model is constructed. After deep research on the two-dimensional flood numerical simulation, the paper constructs the two-dimensional numerical flood model on digital earth platform, and simulates the flood routing.A DEM based flood inundate rendering algorithm is proposed. With reasonable analysis, the flood algorithm is able to calculate the flood submerged region quickly and easily gets assessment data, which is superimposed geography information.Under the premise of accuracy, a forest fire spreading simulation and rendering model is constructed. Based on digital earth platform rendering requirements and existing conditions, the paper simulates the forest fire disaster.A flood and forest fire disaster modeling and rendering prototype system is designed and implemented. There are user interaction, simulation and rendering, reserved interface, and other functions in the prototype system ,and it tests all the key technologies in this paper and provides effective support for forces emergency duty.In summary, the thesis, based on three-dimensional digital earth platform, builds a global common use of flood and forest fire disaster simulation rendering model, which builds solid ground for other relevant applications.