The Key Technique Research Of Forecasting And Early-warning System On Flood-induced Heavy Rain

The heavyrain and flood is more frequently in the south of china,and the task of preventing or controlling flood is more heavily.so it is extremely urgency to build the Flood Forecast and Alert Decision Support System for the South of China,and flood Forecast and Alert is a key sub-system of it.the result of its forecast is a foundation of consulting,controlling and dispatching,information service,taking the gauge of disaster situation.the Research purpose was to apply the technique of real-time rectification base on Rainfall data that was provided by the system of real-time water,rainfall data and elephant product.Combined the expert's experience,it completed the different long predicting time and precision for main course of river.point flood control the reservoir in region,and serve for hydrology department to make the decision.This dissertation was composed summarize, basic theories, system module design,forecast process demonstrating and problem discussion. This dissertation elaborated the important factor of heavyrain forecast — Area Rainfall and the flood-forecast system based on the studying on the theories, model and practices of flood forecast. Especially, the dissertation studied how to improve the method of computing Area Rainfall, the fundamental structure of conceptual hydrological models and mathematical of flood-forecast, and then brought forward a new method to build new model named "model structure-parameter method". This method plus the computer technology make it possible to build flood-forecast model automatically for all the forecast stations of each of valley in the area selected.We could use model structure-parameter method to build model in the system and the user could choose the appropriate model based on the character of this valley. All the parameters was worked out and optimized by system using auto-optimize method. This avoided the subjective mistakes by man and saved a lot of time.Because of the technique advantage of data structure and data stream cause, the interactive river flood forecast could be realized in this system. The interactive flood forecast system's operation was more convenient, and the practical function was strong. It could availably exert expert's experience, so increased the forecast accuracy. That system could transfer and show the weather information directly, so the basis was objective to expert system to interactive forecast. At real time flood forecast, it could make use of the history rain-storm flood data, so could take the advantage of expert experience.which accumulated form forecasting process of history flood analysis.On the basis of carefully analyze flood forecast step, workflow and data streamprocess, flood forecast system design was compose of five function modules, which was the data pre-processing, the flood forecast model establishment and management,the putting real time query, flood forecast, the help on line and maintenance mold piece. The help mold can offer help on line whenever user demand.As forecast and alert decision support information application for meteorologicaldepartment and govenment, we tried to apply the computer technique ------Javatechnique ,the java3D API and the visual Java component library ViaAD.The total construction used the cross-platform's B/ S system, and the distributed processing network system.The application database system, which was a distributed processing real time application system, was established at the Sybase platform, which had strong ability of image processing, multimedia supporting and distributed processing. It made the GIS applied, Internet application, decision support system to combine, completing the system target together. With the databases backstage supporting, the relevant data'sshowing and outputting related to the geographical information of selected valley is displayed perfectly after the second development based on the visual component VisAD.In one word, this thesis brought up the modeling method, construction to count with parameter to combine together. The system development designed the expert interactive flood forecast mode. In the interface system, it was used modular design and object technique, and adopted various safety technique. Its interface was friendly,showed the process and results with the form of sketch, diagram or image. In the end,the system used ChangJiang valley as an example, to dissertate data pre-processing, flood forecast modeling and real time forecast computing simulation. The results were satisfy with demand.